Peptide Guide

46 compounds for weight loss, healing, and optimization. Each profile includes research evidence with PubMed citations, dosing protocols, side effects, and FDA status.

GLP-1 / Weight Loss Peptides

The most effective peptides for significant weight loss. FDA-approved options available.

Semaglutide

glp1-weight-loss

Semaglutide is a GLP-1 receptor agonist originally developed for type 2 diabetes that has demonstrated significant weight loss effects in clinical trials. Sold under the brand names Ozempic (diabetes) and Wegovy (weight management), it is the most prescribed anti-obesity medication worldwide as of 2026. Semaglutide works by mimicking the incretin hormone GLP-1, reducing appetite, slowing gastric emptying, and improving insulin sensitivity. The STEP clinical trial program — spanning over 10,000 participants across multiple studies — established semaglutide as a breakthrough treatment for obesity, with average weight loss of 14.9% over 68 weeks. An oral formulation (Rybelsus for diabetes, oral Wegovy for weight loss) expanded access beyond injection-only delivery. Semaglutide also demonstrated cardiovascular benefits in the SELECT trial, reducing major adverse cardiovascular events by 20% in overweight adults.

Tirzepatide

glp1-weight-loss

Tirzepatide is a first-in-class dual GIP/GLP-1 receptor agonist that has demonstrated greater weight loss than any other approved anti-obesity medication. Sold as Mounjaro (diabetes) and Zepbound (weight management), it activates two complementary incretin pathways simultaneously. The SURMOUNT clinical trial program showed average weight loss of 20.9% at the highest dose — with over half of participants losing 20%+ of body weight. In the landmark SURMOUNT-5 head-to-head trial against semaglutide, tirzepatide produced statistically superior weight loss (20.2% vs 13.7%). Developed by Eli Lilly, tirzepatide represents a paradigm shift from single-receptor to multi-receptor approaches in obesity treatment.

Retatrutide

glp1-weight-loss

Retatrutide (LY3437943) is a first-in-class triple hormone receptor agonist developed by Eli Lilly that simultaneously activates three metabolic pathways: glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucagon receptors. No other obesity medication in clinical development targets all three receptors in a single molecule. The compound emerged from Eli Lilly's incretin research program, with Phase 1b results published in The Lancet in 2022 (PMID: 36354040) demonstrating approximately 9 kg of body weight reduction in just 12 weeks — enough to advance rapidly into Phase 2. The Phase 2 obesity trial, published in the New England Journal of Medicine in 2023 (PMID: 37366315), produced what was then the highest weight loss ever reported for any pharmaceutical agent: 24.2% body weight reduction over 48 weeks at the 12 mg dose. Every participant in the highest dose group lost at least 5% of their body weight, and 83% lost at least 15%. A parallel Phase 2 trial in patients with type 2 diabetes, published in The Lancet in 2023 (PMID: 37385280), demonstrated dual metabolic benefits: up to 16.9% weight loss alongside a 2.02% reduction in HbA1c at 36 weeks. A dedicated liver fat substudy, published in Nature Medicine in 2024 (PMID: 38858523), showed near-complete resolution of hepatic steatosis — 86% relative reduction in liver fat at the highest dose, with 86% of participants dropping below the 5% threshold that defines normal liver fat content. Retatrutide entered Phase 3 in 2023 through the TRIUMPH clinical trial program — a novel basket trial structure testing the compound simultaneously for obesity, obstructive sleep apnea, and knee osteoarthritis across four major studies enrolling over 5,800 participants (PMID: 41090431). The first Phase 3 readout came in December 2025 from TRIUMPH-4, which tested retatrutide specifically in adults with obesity and knee osteoarthritis. Topline results showed 28.7% average body weight loss at 68 weeks (26.6% placebo-adjusted, approximately 71.2 pounds) at the 12 mg dose — peer-reviewed publication pending. The trial also demonstrated a 75.8% reduction in knee osteoarthritis pain scores, with one in eight participants becoming completely free of knee pain. However, TRIUMPH-4 also revealed a new safety signal not seen in Phase 2: dysesthesia (abnormal sensations of touch), occurring in 8.8% of participants at 9 mg and 20.9% at 12 mg versus 0.7% on placebo. While generally mild and infrequently leading to discontinuation, this finding is being closely monitored in subsequent TRIUMPH readouts. Seven additional Phase 3 readouts are expected throughout 2026, including data on obstructive sleep apnea and cardiovascular disease populations. If results remain positive, Eli Lilly is projected to submit a New Drug Application to the FDA in late 2026, with potential approval in the first half of 2027. Retatrutide is not currently available by prescription, through compounding pharmacies, or from research peptide vendors — the FDA has explicitly stated it cannot be legally compounded.

Liraglutide

glp1-weight-loss

Liraglutide is an older GLP-1 receptor agonist requiring daily injection. Sold as Victoza (diabetes) and Saxenda (weight loss), it has been largely superseded by weekly semaglutide but remains widely prescribed.

Survodutide

glp1-weight-loss

Survodutide is a dual GLP-1/glucagon receptor agonist developed by Boehringer Ingelheim, currently in Phase 3 trials for obesity and metabolic liver disease.

Cagrilintide

glp1-weight-loss

Cagrilintide is a long-acting amylin analog being developed by Novo Nordisk, studied in combination with semaglutide (CagriSema) for enhanced weight loss.

Mazdutide

glp1-weight-loss

Mazdutide is a dual GLP-1/glucagon receptor agonist developed by Innovent Biologics, primarily studied in Chinese populations.

Tesofensine

glp1-weight-loss

Tesofensine is a triple monoamine reuptake inhibitor (serotonin, norepinephrine, dopamine) that reduces appetite through central nervous system pathways different from GLP-1 agonists.

Metabolic & Fat Loss

Peptides that target fat metabolism, visceral fat, and body composition.

AOD-9604

metabolic

AOD-9604 is a modified fragment of human growth hormone (hGH fragment 176-191) that stimulates fat breakdown without the growth-promoting effects of full HGH.

MOTS-c

metabolic

MOTS-c is a mitochondrial-derived peptide that regulates metabolic homeostasis and has been called an "exercise mimetic" for its ability to activate AMPK pathways.

SLU-PP-332

metabolic

SLU-PP-332 is an ERR (estrogen-related receptor) agonist that mimics the effects of endurance exercise on gene expression and metabolism.

Follistatin

metabolic

Follistatin is a glycoprotein that inhibits myostatin, the protein that limits muscle growth. By blocking myostatin, follistatin allows for enhanced muscle development.

Healing & Recovery

Tissue repair, gut healing, and injury recovery peptides — including GLP-1 side effect support.

BPC-157

healing-recovery

BPC-157 (Body Protection Compound-157) is a synthetic pentadecapeptide consisting of 15 amino acids derived from a protective protein found naturally in human gastric juice. First isolated and characterized by researcher Predrag Sikiric and his team at the University of Zagreb in the early 1990s, BPC-157 has become one of the most extensively studied peptides in preclinical research, with over 100 published studies investigating its effects across multiple organ systems. The compound earned the nickname "the Wolverine peptide" in biohacking communities due to the breadth of tissue repair observed in animal studies. Research spanning more than three decades has documented effects on tendons, ligaments, muscles, bones, skin, corneas, the gastrointestinal tract, liver, and nervous system in preclinical models. A 2025 systematic review published in HSS Journal (PMID: 40756949) analyzed 36 studies conducted between 1993 and 2024, finding that BPC-157 consistently improved outcomes across musculoskeletal injury models. Despite this extensive preclinical evidence, human clinical data remains extremely limited. As of March 2026, only three small human studies have been published: a 2-person intravenous safety pilot (PMID: 40131143), a small retrospective knee pain study, and a 12-patient interstitial cystitis pilot. The knee pain study reported significant relief in most participants at 6-12 months, and the cystitis pilot reported substantial symptom improvement. Neither of these smaller studies has been published with full peer-reviewed PMIDs. A Phase I safety trial (NCT02637284) was registered by PharmaCotherapia but the sponsor never published results, raising transparency concerns in the research community. BPC-157 is classified as a research compound and is not FDA-approved for any human use. In 2023, the FDA placed BPC-157 in Category 2 of its list of bulk drug substances under evaluation for compounding, meaning it does not meet safety criteria for pharmacy compounding. The World Anti-Doping Agency (WADA) added BPC-157 to its prohibited substances list in 2022 under the S0 category (non-approved substances). Despite these regulatory designations, BPC-157 continues to be widely discussed in peptide research communities and functional medicine circles. The compound is available in injectable and oral forms. Most preclinical research has used subcutaneous or intraperitoneal injection, though studies have also demonstrated activity when administered orally, particularly for gastrointestinal conditions. An important distinction exists between the acetate salt and arginate salt forms. The arginate form reportedly demonstrates significantly better oral bioavailability and stability, though head-to-head bioavailability studies have not been published in peer-reviewed journals. A comprehensive preclinical safety evaluation published in Regulatory Toxicology and Pharmacology (PMID: 32334036) tested BPC-157 across multiple species including mice, rats, rabbits, and dogs. The study found no test-related adverse effects in single-dose or repeated-dose toxicity evaluations, no genetic toxicity, and no embryo-fetal toxicity at doses up to 20 mg/kg over six weeks. However, the absence of large-scale human safety trials means that the long-term safety profile in humans remains unknown. The primary mechanisms through which BPC-157 appears to exert its effects involve the promotion of angiogenesis, modulation of nitric oxide synthesis through multiple pathways, upregulation of growth factor receptors, and interaction with the dopamine and serotonin neurotransmitter systems. These mechanisms have been documented across dozens of studies spanning multiple research groups. BPC-157 occupies a unique position in the peptide landscape. Its broad preclinical evidence base across tissue types, combined with the near-total absence of human clinical trials, creates a significant gap between what animal research suggests and what has been demonstrated in people. All information on this page reflects published research and is presented for educational purposes only.

TB-500

healing-recovery

TB-500 is a synthetic version of Thymosin Beta-4 (Tb4), a naturally occurring 43-amino-acid protein that constitutes 70-80% of all beta-thymosins in the human body (PMID: 36464872). While the name "TB-500" is sometimes described as a fragment, most commercial TB-500 products contain the full 43-amino-acid Thymosin Beta-4 sequence. The key active region is the actin-binding domain (amino acids 17-23, the sequence LKKTETQ), which is responsible for promoting cell migration, angiogenesis, and tissue repair — the properties that have driven research interest since the early 2000s. Thymosin Beta-4 was originally isolated from the thymus gland in 1981 and initially studied for its role in immune function. Researchers later discovered broader tissue repair properties, leading to the foundational dermal wound study (PMID: 12581423) which demonstrated accelerated wound closure through enhanced cell migration, collagen deposition, and new blood vessel formation in animal models. This established the mechanistic rationale for all subsequent TB-500 research. The only published human clinical trials for Thymosin Beta-4 are in ophthalmology. RegeneRx Biopharmaceuticals developed RGN-259, a topical eye drop formulation containing 0.1% Thymosin Beta-4, which completed two Phase 2 randomized controlled trials for dry eye disease. The first trial in severe dry eye patients including those with graft-versus-host disease showed a 35.1% reduction in ocular discomfort and 59.1% reduction in corneal staining versus placebo (PMID: 25826322). A second trial in 72 subjects showed a 27% reduction in discomfort scores described as safe and well tolerated (PMID: 26056426). Note: primary endpoints in the second trial did not reach significance, though secondary endpoints showed improvement. Effects from the first trial persisted 28 days after treatment ended. Three subsequent Phase 3 dry eye trials (ARISE-1, -2, -3) did not meet their pre-specified co-primary endpoints, though secondary endpoints showed some statistical significance in pooled analyses. Cardiac repair represents the most researched preclinical application. Multiple animal studies demonstrate that Thymosin Beta-4 protects cardiac tissue after myocardial infarction by reducing oxidative damage, inhibiting fibrosis, and promoting new blood vessel formation (PMID: 35712678, 34335970). RegeneRx developed a clinical program for acute myocardial infarction treatment and completed Phase 1 safety protocols, but Phase 2 cardiac trial results were never published and the program appears to have stalled. Hair growth is another well-researched preclinical area. Mouse studies show that Thymosin Beta-4 overexpression leads to faster hair re-growth, higher hair shaft counts, and follicle clustering through P38/ERK/AKT/VEGF signaling pathways (PMID: 26083021). A 2021 review confirmed that exogenous Tb4 accelerates hair follicle cycle transitions and promotes migration of hair follicle stem cells (PMID: 33393222). No human hair growth trials have been published. A 2024 pharmacokinetic study introduced a finding that may reframe understanding of how TB-500 works: the metabolite Ac-LKKTE — not the parent TB-500 molecule — showed significant wound repair activity in vitro (PMID: 38382158). This suggests TB-500's reported effects in earlier studies may have been driven by its metabolic breakdown products rather than the intact peptide. Thymosin Beta-4 also demonstrates potent anti-fibrotic properties. It prevents fibrosis across multiple organ systems in animal models, and its N-terminal fragment Ac-SDKP can not only prevent but reverse established fibrosis in liver, lung, heart, and kidney tissue (PMID: 36580759). TB-500 is not FDA-approved for any indication. The FDA classified it as a Category 2 compound, restricting it from compounding pharmacy preparation. In February 2026, the Department of Health and Human Services announced plans to potentially reclassify certain peptides including Thymosin Beta-4, which could affect future regulatory accessibility. TB-500 is prohibited by the World Anti-Doping Agency (WADA) at all times as a Non-Specified Substance under category S2 (Peptide Hormones, Growth Factors, and Related Substances), with first-offense violations carrying a four-year ban. The U.S. Department of Defense has adopted WADA categories, making TB-500 prohibited for all military personnel. Despite its research-only status, TB-500 has been widely used in veterinary medicine, particularly in equine practice for soft tissue injuries — one of the earliest real-world applications that drove interest in human research. The combination of TB-500 with BPC-157, commonly called the "Wolverine Stack" in peptide communities, is one of the most discussed recovery-focused protocols, though no published studies have tested this combination in humans or animals.

Thymosin Beta-4

healing-recovery

Thymosin Beta-4 is the full-length naturally occurring protein from which TB-500 is derived. It plays a central role in tissue repair, cell migration, and immune modulation.

KPV

healing-recovery

KPV is a tripeptide fragment of alpha-MSH with potent anti-inflammatory properties, primarily studied for gut inflammation and inflammatory bowel conditions.

LL-37

healing-recovery

LL-37 is a human antimicrobial peptide (cathelicidin) that plays a key role in innate immune defense against bacteria, viruses, and fungi.

ARA-290

healing-recovery

ARA-290 is a non-erythropoietic peptide derived from erythropoietin (EPO) that provides tissue protection and repair without stimulating red blood cell production.

Growth Hormone

GH secretagogues for body recomposition, sleep, and recovery.

Ipamorelin

gh-secretagogue

Ipamorelin is a synthetic pentapeptide and growth hormone releasing peptide (GHRP) that stimulates the pituitary gland to secrete growth hormone through selective activation of the ghrelin receptor (GHS-R1a). Developed in the late 1990s by Novo Nordisk, it was characterized in a landmark 1999 study as the first GHRP to release GH with absolute selectivity, meaning it does not significantly elevate cortisol, prolactin, ACTH, FSH, or LH at pharmacological doses (PMID: 10580762). This hormonal selectivity distinguishes it from older GHRPs like GHRP-2 and GHRP-6, which produce meaningful cortisol and prolactin elevations that can complicate long-term use. Ipamorelin is most commonly combined with CJC-1295 (a GHRH analog) to produce synergistic GH release through dual-pathway stimulation. The two peptides act on different receptors and when administered together produce GH output substantially greater than either compound alone. This combination has become one of the most widely used peptide protocols in anti-aging medicine and performance-oriented use. Ipamorelin was placed on the FDA Category 2 bulk drug substance list in 2023, restricting compounding pharmacy production, though regulatory status remained in flux following a February 2026 announcement from HHS regarding potential reinstatement of certain peptides.

CJC-1295

gh-secretagogue

CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH) engineered to dramatically extend the half-life of natural GHRH signaling. Developed by ConjuChem Biotechnologies in the early 2000s, it exists in two distinct forms that are frequently confused: CJC-1295 with DAC (Drug Affinity Complex) and CJC-1295 without DAC, also known as Modified GRF (1-29) or mod GRF 1-29. Understanding this distinction is essential — they share a name but have fundamentally different pharmacokinetic profiles. The DAC version uses a reactive chemical group called maleimidopropionic acid (MPA) that forms a covalent bond with serum albumin after injection. This albumin binding shields the peptide from enzymatic degradation and extends its half-life from minutes to 5.8-8.1 days (PMID: 16352683). Native GHRH has a half-life of approximately 7 minutes, making this roughly a 1,000-fold improvement in duration. The landmark Teichman et al. trial demonstrated that a single CJC-1295 DAC injection produced dose-dependent GH increases of 2- to 10-fold sustained for 6 or more days, with IGF-I levels rising 1.5- to 3-fold for 9-11 days (PMID: 16352683). The no-DAC version (mod GRF 1-29) has four amino acid substitutions at positions 2, 8, 15, and 27 that improve stability against dipeptidylpeptidase-IV (DPP-IV) cleavage compared to native GHRH, but without albumin binding, its half-life is approximately 30 minutes. This shorter duration preserves the natural pulsatile pattern of GH release — the body's own rhythm of GH spikes followed by quiet periods — which many researchers and clinicians consider preferable to the continuous elevation produced by the DAC form. A critical finding from the Ionescu and Frohman study confirmed that even the DAC version preserves GH pulsatility: basal GH levels increased 7.5-fold, but GH pulse frequency and magnitude remained unchanged, meaning the pituitary's natural secretory rhythm was maintained rather than overridden (PMID: 17018654). This is a meaningful safety distinction from exogenous HGH, which produces flat, supraphysiologic GH levels that suppress the body's own production. CJC-1295 has never been FDA-approved for any indication. A Phase II clinical trial of the DAC version for HIV-associated lipodystrophy was halted in July 2006 after a participant died hours after his 11th injection at an Argentine study site. The cause of death was confirmed as acute myocardial infarction. The attending physician attributed the MI to pre-existing asymptomatic coronary artery disease unrelated to CJC-1295 treatment. The study enrolled 192 HIV-positive participants with significant cardiovascular risk factors, and ConjuChem eventually went bankrupt without completing the trial. The FDA flagged cardiac concerns when reviewing CJC-1295 during the 2024 PCAC process, indicating the regulatory signal was not fully dismissed. This remains the only reported fatality associated with CJC-1295. CJC-1295 was placed on the FDA Category 2 bulk drug substance list in late 2023, effectively prohibiting compounding pharmacies from preparing it. In September 2024, the FDA referred it to the Pharmacy Compounding Advisory Committee (PCAC), which flagged cardiac side effects and immunogenicity concerns. On February 27, 2026, HHS Secretary RFK Jr. announced that approximately 14 of 19 restricted peptides would return to legal compounding status, though the specific list has not been officially published and CJC-1295's inclusion remains uncertain due to its cardiac flagging. CJC-1295 is prohibited at all times by WADA under S2: Peptide Hormones, Growth Factors, Related Substances and Mimetics.

Sermorelin

gh-secretagogue

Sermorelin (GRF 1-29) is the shortest fully active fragment of growth hormone-releasing hormone (GHRH), consisting of the first 29 of 44 amino acids in natural GHRH. It holds a unique position among growth hormone secretagogue peptides as the only one that was ever FDA-approved — marketed as Geref by Serono Labs, first approved in December 1990 for diagnostic evaluation of pituitary growth hormone secretion, then approved again in September 1997 for therapeutic treatment of idiopathic growth hormone deficiency in children. EMD Serono voluntarily withdrew Geref from the market in 2008 — not because of safety concerns, but because recombinant human growth hormone (rhGH) had become the standard of care for pediatric GH deficiency. The FDA formally confirmed this in a March 2013 Federal Register notice, stating that Geref "was not withdrawn from sale for reasons of safety or effectiveness." This distinction matters: sermorelin has a formal FDA safety determination that no other GH secretagogue peptide can claim. Unlike exogenous growth hormone, which bypasses the body's regulatory mechanisms, sermorelin stimulates the pituitary gland to produce and release GH in the natural pulsatile pattern governed by the hypothalamic-pituitary axis. Somatostatin — the body's GH brake — remains functional, preventing the supraphysiologic GH levels that can occur with direct HGH injection (PMID: 18046908). The result is a self-limiting system: the body cannot be pushed into GH excess through sermorelin alone. Clinical evidence spans multiple domains. The landmark Thorner multicenter trial demonstrated that sermorelin at 30 mcg/kg/day increased height velocity from 4.1 to 8.0 cm/year in GH-deficient children, with 74% showing good response at 6 months (PMID: 8772599). In aging adults, Corpas et al. showed that 14 days of twice-daily GHRH(1-29) at the highest tested dose restored GH and IGF-I levels in a small group of elderly men (n=10) to ranges comparable to young controls (PMID: 1379256). A 16-week placebo-controlled trial by Khorram et al. found significant increases in lean body mass (+1.26 kg in men, P < 0.05), improved insulin sensitivity, enhanced skin thickness, and increased IGF-I levels (PMID: 9141536). Cognitive benefits have been demonstrated in the GHRH class. A large randomized controlled trial (n=152) using tesamorelin (a related GHRH analog acting on the same receptor) showed that 20 weeks of treatment significantly improved executive function (P = 0.005), with benefits comparable across healthy older adults and those with mild cognitive impairment (PMID: 22869065). A companion NIH study using sermorelin acetate specifically confirmed improvements in working memory, planning, and processing speed, along with decreased body fat and increased lean mass (PMID: 22034239). Sleep is one of sermorelin's most consistently reported effects. Research shows that GHRH administered during the first half of the night increases slow-wave sleep and enhances GH release, though timing is critical — morning administration does not produce the same sleep architecture benefits (PMID: 9089471). Sermorelin was never placed on the FDA's Category 2 bulk drug substance list during the 2023-2024 peptide regulatory actions that restricted compounds like CJC-1295, ipamorelin, and BPC-157. It remains legally compoundable under Section 503A of the FD&C Act and available via prescription through licensed compounding pharmacies. It is not a controlled substance. For athletes, sermorelin is prohibited by WADA under S2: Peptide Hormones, Growth Factors, Related Substances and Mimetics, at all times in and out of competition.

Tesamorelin

gh-secretagogue

Tesamorelin (brand name Egrifta) is a stabilized synthetic analog of growth hormone-releasing hormone (GHRH) and the only FDA-approved GH secretagogue currently on the market. The FDA approved it in November 2010 for reducing excess abdominal fat in HIV-infected patients with lipodystrophy, a condition where antiretroviral therapy redistributes fat from the limbs to the abdomen and trunk. This approval rests on two pivotal Phase 3 trials published in the New England Journal of Medicine showing tesamorelin produced a 15-18% reduction in visceral adipose tissue (VAT) compared to placebo over 26 weeks (PMID: 20395564). Tesamorelin is a 44-amino acid peptide, identical in length to endogenous GHRH, with a trans-3-hexenoic acid modification on the N-terminus that slows enzymatic degradation and extends its half-life. Unlike sermorelin (29 amino acids) or CJC-1295 (which extends half-life through albumin binding), tesamorelin achieves its stability through chemical modification of the peptide backbone itself. It acts exclusively on the GHRH receptor (GHRHR) using the same mechanism as endogenous GHRH, stimulating pituitary somatotrophs to release GH in the body's natural pulsatile pattern while preserving the somatostatin feedback loop. Beyond its approved lipodystrophy indication, tesamorelin has been studied in two additional populations: healthy older adults and patients with mild cognitive impairment (MCI). A large NIH-funded 152-subject RCT found that 20 weeks of tesamorelin significantly improved executive function (P = 0.005) across both healthy aging and MCI groups, with no worsening of glucose tolerance in non-diabetic subjects (PMID: 22869065). A separate RCT found it significantly increased muscle density and lean muscle area across four trunk muscle groups in HIV patients compared to placebo (PMID: 31237318). These findings have driven off-label interest in anti-aging and cognitive health applications.

GHRP-2

gh-secretagogue

GHRP-2 (Growth Hormone Releasing Peptide-2) is a synthetic hexapeptide that stimulates growth hormone release by activating the ghrelin receptor (GHS-R1a) in the pituitary gland and hypothalamus. It was developed as a second-generation GHRP with greater potency than GHRP-6, its predecessor, while producing somewhat less dramatic appetite stimulation. GHRP-2 occupies a middle ground in the GHRP family: more selective than GHRP-6, which triggers extreme hunger, but less selective than ipamorelin, which produces minimal cortisol or prolactin elevation. Research in healthy adults and GH-deficient patients has documented robust GH pulses following GHRP-2 administration, typically peaking within 15 to 60 minutes of injection (PMID: 9467542). Because GHRP-2 also raises cortisol and prolactin, its side effect profile is broader than ipamorelin but narrower than GHRP-6 or hexarelin.

GHRP-6

gh-secretagogue

GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide and the original member of the GHRP family, first synthesized in the 1980s as part of the search for orally active GH secretagogues. It was the compound that established the GHRP drug class and led to the eventual development of GHRP-2, ipamorelin, hexarelin, and the oral ghrelin mimetic MK-677. GHRP-6 acts as a full agonist at the growth hormone secretagogue receptor type 1a (GHS-R1a), producing robust GH release alongside the most pronounced appetite stimulation of any injectable GHRP. This intense hunger effect, caused by potent central ghrelin receptor activation, makes GHRP-6 the compound of choice for individuals struggling to eat enough calories, whether due to illness, extremely high metabolic demands, or recovery from muscle-wasting conditions. For users who do not need appetite stimulation, the appetite effect is a significant drawback, and other GHRPs offer similar GH stimulation with less interference with hunger control (PMID: 9467542). GHRP-6 also produces measurable cortisol and prolactin elevation, more so than ipamorelin but similar to GHRP-2.

Hexarelin

gh-secretagogue

Hexarelin is a synthetic hexapeptide and the most potent growth hormone releasing peptide (GHRP) by raw GH output, producing larger GH pulses than GHRP-2, GHRP-6, or ipamorelin at equivalent doses (PMID: 9467542). It shares the core GHRP mechanism, acting as a full agonist at the ghrelin receptor (GHS-R1a) to stimulate pituitary GH release, but its higher receptor binding affinity and potency also produce the steepest desensitization curve and the most pronounced cortisol and prolactin elevation in the class. These tradeoffs make hexarelin a specialized compound: its peak GH output is useful for short-burst protocols where maximum GH exposure over a 4 to 8 week window is the goal, but it is unsuitable for longer cycles because receptor desensitization progressively blunts its GH-stimulating response (PMID: 7671860). Beyond its GH-stimulating properties, hexarelin has attracted research interest for cardioprotective effects that appear to operate through a GH-independent pathway, making it one of the few GHRPs with potential cardiac applications outside of GH optimization (PMID: 10594485).

IGF-1 LR3

gh-secretagogue

IGF-1 LR3 is a modified version of insulin-like growth factor 1 with a longer half-life, promoting muscle growth and recovery.

MGF

gh-secretagogue

MGF (Mechano Growth Factor) is a splice variant of IGF-1 produced in response to muscle damage, promoting satellite cell activation and muscle repair.

Anti-Aging

Longevity, skin health, and cellular health peptides.

GHK-Cu

anti-aging

GHK-Cu (glycyl-L-histidyl-L-lysine:copper(II)) is a naturally occurring tripeptide-copper complex discovered in 1973 by biochemist Loren Pickart. His laboratory found that older human liver tissue exposed to GHK-Cu produced proteins more characteristic of younger tissue — a finding that launched over five decades of continuous research into this peptide's regenerative properties. The molecule consists of three amino acids (glycine, histidine, lysine) bound to a copper(II) ion, and it occurs naturally in human plasma, saliva, and urine. In young adults, circulating GHK-Cu levels average approximately 200 ng/mL. By age 60, those levels decline to roughly 80 ng/mL — a reduction of more than 60% that correlates with visible signs of aging and diminished tissue repair capacity (PMID: 35083444). GHK-Cu is one of the most broadly studied peptides in the research literature, with effects documented across skin, lung, bone, liver, stomach, and nervous system tissue. Gene profiling studies using the Broad Institute Connectivity Map have identified over 4,000 human genes whose expression changes in response to GHK-Cu treatment, making it one of the most broadly active gene modulators among known bioactive peptides (PMID: 26236730). Key pathways with direct experimental confirmation include collagen synthesis, DNA repair, antioxidant defense, inflammatory signaling, and cellular senescence — though not all 4,000+ gene changes have been individually validated beyond the computational profiling. The strongest evidence clusters around four areas: skin regeneration and anti-aging (with collagen synthesis data dating to 1988), wound healing (across multiple tissue types), lung protection and COPD reversal (four separate studies demonstrating gene expression normalization in diseased lung tissue), and gene modulation (three major reviews covering the 4,000+ gene dataset). A 2025 study extended the research into gastrointestinal health, demonstrating GHK-Cu's ability to alleviate ulcerative colitis in mice through the SIRT1/STAT3 pathway (PMID: 40672369). In the cancer research context, GHK-Cu presents a paradox that warrants caution. While it promotes angiogenesis (blood vessel growth) — which could theoretically support tumor growth — a computational gene expression screen (Connectivity Map) of 1,309 bioactive compounds found that GHK was one of only two whose transcriptional profile reversed a 54-gene metastatic signature in colorectal cancer (PMID: 20143136). This reflects gene expression pattern matching, not direct anti-cancer testing, and no follow-up cancer model studies have been published since 2010. Individuals with active or suspected cancer should consult their oncologist before using GHK-Cu. GHK-Cu is available in multiple delivery formats. Topical serums and creams (typically 1-3% concentration) represent the most common and well-studied application, with decades of published human data supporting skin improvements. Injectable GHK-Cu provides systemic delivery at higher tissue concentrations but relies primarily on animal and in vitro evidence for most indications. Microneedling combined with topical GHK-Cu has emerged as a popular middle-ground approach, with research showing that microneedle-treated skin absorbs significantly more peptide than intact skin alone. GHK-Cu is also known by its cosmetic industry name, Copper Tripeptide-1 (INCI designation). Its chemical structure naturally occurs within the alpha 2(I) chain of type I collagen, suggesting that the body releases GHK-Cu at wound sites through proteolytic breakdown of damaged collagen — a built-in mechanism for initiating local repair (PMID: 3169264). The regulatory landscape for GHK-Cu differs between topical and injectable forms. Topical copper peptide products are classified as cosmetics and remain widely available over the counter. Injectable GHK-Cu was placed on the FDA's Category 2 list in September 2023, restricting compounding. In February 2026, HHS Secretary Robert F. Kennedy Jr. announced that approximately 14 of 19 Category 2 peptides would be reclassified back to Category 1 — GHK-Cu is on that list. As of March 2026, the formal FDA list update has not yet been published, with implementation expected through mid-2026. GHK-Cu has never been FDA-approved as a drug for any indication, and injectable use remains an off-label prescription through compounding pharmacies. GHK-Cu is not on the WADA prohibited list.

Epitalon

anti-aging

Epitalon (also spelled Epithalon) is a synthetic tetrapeptide with the amino acid sequence Ala-Glu-Asp-Gly (AEDG). It was developed in the 1980s by Professor Vladimir Khavinson at the St. Petersburg Institute of Bioregulation and Gerontology in Russia, derived from epithalamin — a polypeptide complex extracted from the bovine pineal gland. In 2017, mass spectrometry confirmed that AEDG is the specific active component within the natural pineal extract, comprising part of the 22.10% tetrapeptide fraction identified in the complex (PMID: 29124531). Epitalon's primary research interest centers on telomerase activation — the ability to stimulate the enzyme responsible for maintaining telomere length during cell division. In 2003, Khavinson's group first demonstrated that Epitalon could reactivate telomerase in normal human somatic cells (PMID: 12937682). A follow-up study showed treated cells bypassed the Hayflick limit, completing 44 passages compared to 34 in untreated controls while maintaining normal cell morphology (PMID: 15455129). In 2025, an independent Western laboratory confirmed dose-dependent telomere extension in normal human cells, providing the first replication of the core claim outside of Russia (PMID: 40908429). Beyond telomere maintenance, Epitalon research spans five overlapping mechanisms: telomerase activation, epigenetic remodeling (chromatin decondensation in aged cells), circadian rhythm restoration via melatonin synthesis, antioxidant enzyme induction, and immune system modulation. This multi-target profile distinguishes it from most anti-aging compounds that address a single pathway. The human clinical data comes primarily from studies using epithalamin (the natural extract rather than synthetic Epitalon). The longest study — a 12-year trial in approximately 79 elderly patients with coronary disease (39 treated, 40 control) — reported 28% fewer deaths and 2-fold lower cardiovascular mortality in the treatment group, though the small sample size and unspecified blinding methodology limit the strength of these conclusions (PMID: 17426848). A separate 6-8 year study of 266 elderly patients found epithalamin treatment reduced mortality 1.6-1.8-fold (PMID: 14523363). An important caveat applies to all Epitalon research: the vast majority of published studies originate from Khavinson's group at the St. Petersburg Institute. Until the 2025 independent replication (PMID: 40908429), no Western laboratory had confirmed the telomerase activation claims. While the consistency of results across 25+ years and multiple species is noteworthy, the concentration of research in a single laboratory represents a meaningful limitation in the evidence base. No Phase III clinical trials or FDA-reviewed studies exist. The cancer/telomerase paradox is central to understanding Epitalon's safety profile. Telomerase is reactivated in approximately 90% of human cancers, raising theoretical concern that stimulating telomerase could promote tumor growth. However, animal studies tell a more complex story. In HER-2/neu transgenic mice (genetically predisposed to breast cancer), Epitalon treatment reduced tumor incidence, delayed onset, decreased metastases, and extended lifespan (PMID: 12459848). A 2025 independent study found a cell-type-specific mechanism: in cancer cell lines, Epitalon extended telomeres through ALT (Alternative Lengthening of Telomeres) rather than telomerase upregulation, while normal cells used the telomerase pathway (PMID: 40908429). However, ALT is itself a pro-tumorigenic mechanism used by 10-15% of cancers, associated with genomic instability. Whether this differential pathway explains the anti-tumor animal results or introduces a different risk is an open question that cannot be resolved by one in vitro study using two cell lines. Epitalon is classified as research-only by the FDA. In late 2023, the FDA placed it on the Category 2 list (do not compound), citing immunogenicity risk. In February 2026, HHS Secretary Robert F. Kennedy Jr. announced that approximately 14 of the 19 Category 2 peptides were expected to return to Category 1, which would allow licensed compounding pharmacies to prepare them under physician prescription. As of March 2026, the formal FDA updated list has not been published. In Russia, epithalamin-based preparations have been used clinically for menopause, anovulatory infertility, and as adjunctive therapy for hormone-dependent tumors.

FOXO4-DRI

anti-aging

FOXO4-DRI is a senolytic peptide designed to selectively destroy senescent (zombie) cells that accumulate with aging and contribute to chronic inflammation.

SS-31

anti-aging

SS-31 (Elamipretide) is a mitochondria-targeted peptide that restores mitochondrial function and has been studied in clinical trials for heart failure and mitochondrial diseases.

NAD+

anti-aging

NAD+ (Nicotinamide Adenine Dinucleotide) is a coenzyme essential for cellular energy production and DNA repair that declines significantly with age.

Humanin

anti-aging

Humanin is a 24-amino-acid mitochondrial-derived peptide (MDP) encoded within the 16S ribosomal RNA gene of mitochondrial DNA. Discovered in 2001, it was the first identified MDP and has demonstrated neuroprotective, cytoprotective, and metabolic regulatory properties in preclinical research. It is being studied for its role in Alzheimer disease, type 2 diabetes, and age-related decline.

Cognitive

Brain-targeting peptides for focus, memory, and neuroprotection.

Semax

nootropic

Semax is a synthetic peptide analog of ACTH(4-10) developed in Russia, used clinically there for cognitive enhancement, stroke recovery, and neuroprotection.

Selank

nootropic

Selank is a synthetic analog of the immunomodulatory peptide tuftsin with anxiolytic and nootropic properties, approved for clinical use in Russia.

Cerebrolysin

nootropic

Cerebrolysin is a porcine brain-derived peptide preparation used clinically in many countries for stroke recovery, traumatic brain injury, and dementia.

Dihexa

nootropic

Dihexa is an extremely potent cognitive-enhancing peptide reported to be 10 million times more potent than BDNF at promoting new neural connections.

Pinealon

nootropic

Pinealon is a tripeptide (Glu-Asp-Arg) that crosses the blood-brain barrier and has neuroprotective properties, developed by Russian researchers.

Other

Additional peptides covering immune support, sexual health, and more.

PT-141

other

PT-141 (Bremelanotide) is FDA-approved for hypoactive sexual desire disorder in women. It works through the melanocortin system rather than the vascular system like Viagra.

Melanotan II

other

Melanotan II (MT-II) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH) developed at the University of Arizona in the 1980s by researchers Victor Hruby and Mac Hadley. Originally designed as a sunless tanning agent to reduce skin cancer risk, MT-II turned out to be far more pharmacologically complex than anticipated. As a non-selective melanocortin receptor agonist binding MC1R, MC3R, MC4R, and MC5R, it produces a constellation of effects spanning skin pigmentation, sexual function, appetite regulation, and energy homeostasis. The first human clinical trial (PMID: 8637402) was published in 1996 in Life Sciences. Three healthy male volunteers received subcutaneous injections of MT-II at doses ranging from 0.01 to 0.03 mg/kg over two weeks. Skin pigmentation increased measurably in facial, upper body, and buttock regions. However, the trial also documented unexpected effects: nausea, somnolence, and spontaneous penile erections. These unanticipated sexual side effects redirected the research trajectory entirely. Subsequent double-blind, placebo-controlled studies (PMID: 9679884, 11035391, 11018622) demonstrated that MT-II could initiate erections in men with both psychogenic and organic erectile dysfunction, with efficacy rates of 63-85% compared to 5-19% for placebo. These effects appeared to originate centrally — MT-II acted at the brain level through MC4R activation, producing what researchers described as a rather natural sexual response (PMID: 15996790). This sexual function research directly led to the development of bremelanotide (PT-141), a metabolite of MT-II that was refined into Vyleesi and received FDA approval in June 2019 for hypoactive sexual desire disorder (HSDD) in premenopausal women. MT-II itself never achieved FDA approval. Development as a pharmaceutical tanning agent was halted around 2003 due to safety concerns including elevated blood pressure and the challenge of non-selective receptor binding producing too many off-target effects for a cosmetic product. A linear analog called afamelanotide (originally designated Melanotan I) was developed separately and received FDA approval as Scenesse in October 2019 for erythropoietic protoporphyria (EPP), a rare genetic photosensitivity disorder. The distinction matters: afamelanotide selectively targets MC1R only (pigmentation), while MT-II non-selectively activates multiple receptor subtypes. Despite never being approved for human use, MT-II gained widespread underground adoption through the peptide community beginning in the mid-2000s. A 2009 BMJ editorial (PMID: 19224885) addressed the growing unregulated use in the general population. Users typically self-administer via subcutaneous injection or nasal spray, sourcing from online research chemical vendors. A 2014 analysis found 4-6% impurities in MT-II products purchased online, underscoring quality concerns inherent to the unregulated market. Animal research has demonstrated MT-II effects on energy balance through MC3R and MC4R activation. Rat studies using intracerebroventricular (direct brain) infusion showed intermittent MT-II administration reduced adiposity by up to 80% and produced chronic body mass reduction without sustained caloric restriction (PMID: 20034526, 28051332). These results used a route of administration that does not reflect subcutaneous injection in humans. Human weight-loss data remains limited to anecdotal community reports and incidental appetite suppression observed during clinical trials. The safety profile includes documented case reports of rhabdomyolysis from overdose (PMID: 23121206), renal infarction (PMID: 31953620), and melanoma emerging from existing moles (PMID: 24355990). A 2017 comprehensive review (PMID: 28266027) documented four melanoma cases among MT-II users. Causation remains unproven — some reviews suggest increased UV-seeking behavior among users may partly explain the association, but direct melanocyte overstimulation is also a plausible mechanistic pathway. A 2025 case report documented oral mucosal melanoma in a young MT-II nasal spray user, a non-UV-exposed site, suggesting risk may not be limited to UV behavior alone. Health authorities in the US, Australia, UK, and EU have issued warnings against unregulated MT-II use. MT-II is not classified as a controlled substance but is expected to remain on the restricted peptide list under the anticipated 2026 FDA reclassification.

Gonadorelin

other

Gonadorelin is a synthetic GnRH (gonadotropin-releasing hormone) used to stimulate LH and FSH production, often prescribed to maintain fertility during testosterone therapy.

Kisspeptin

other

Kisspeptin is a neuropeptide that triggers the release of GnRH, playing a key role in puberty onset and reproductive hormone regulation.

DSIP

other

DSIP (Delta Sleep Inducing Peptide) is a neuropeptide that promotes delta wave sleep, the deepest and most restorative phase of the sleep cycle.

Oxytocin

other

Oxytocin is the naturally occurring "bonding hormone" available in synthetic form. FDA-approved for labor induction and postpartum hemorrhage, it is also studied for social anxiety and bonding.

VIP

other

VIP (Vasoactive Intestinal Peptide) is a neuropeptide with potent anti-inflammatory and immune-modulating properties, studied for mold illness and CIRS.

Melanotan I

other

Melanotan I (afamelanotide) is a linear analog of alpha-melanocyte-stimulating hormone that selectively targets MC1R to increase melanin production. Unlike Melanotan II, it does not activate sexual function pathways. FDA-approved as Scenesse for erythropoietic protoporphyria (EPP), a rare genetic photosensitivity disorder.