Growth Hormone Peptides: Ipamorelin, CJC-1295, Sermorelin & More
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GH stimulation (not exogenous)
Written by Alejandro Reyes
Founder & Lead Researcher
Reviewed by Peptide Nerds Editorial · Updated March 2026
Medical disclaimer: This guide is for educational purposes only and is not medical advice. Most GH peptides discussed here are research compounds not approved by the FDA for general use. Always consult a qualified healthcare provider before starting any medication or peptide protocol. See our full medical disclaimer.
In this guide
How growth hormone peptides work
Growth hormone secretagogues are peptides that stimulate the pituitary gland to produce and release its own growth hormone. This is the fundamental distinction from exogenous HGH, which bypasses the pituitary entirely and delivers synthetic growth hormone directly into the bloodstream.
Secretagogues work through two main signaling pathways, and understanding these two pathways is the key to understanding every GH peptide on the market.
Pathway 1: GHRH analogs. These mimic growth hormone-releasing hormone, the signal the hypothalamus sends to the pituitary to begin GH production and release. CJC-1295 and sermorelin work this way. They amplify the natural release signal. Think of them as turning up the volume on a message the body is already sending.
Pathway 2: Ghrelin mimetics (GHRPs). These activate the ghrelin receptor (GHS-R1a), a separate pathway that triggers GH release independently of GHRH. Ipamorelin, GHRP-2, and GHRP-6 work this way. They open a second door to GH release that operates independently of the GHRH pathway.
The critical concept is pulsatile release. The body naturally releases GH in pulses throughout the day, with the largest pulse occurring during deep sleep. Secretagogues preserve this pulsatile pattern. Exogenous HGH does not. A flat, constant level of GH in the bloodstream carries a different risk profile than the natural surge-and-recede pattern the body evolved to handle.
This is also why stacking a GHRH analog with a ghrelin mimetic is so effective. Activating both pathways simultaneously produces a GH pulse that is significantly larger than either pathway can generate alone. The two signals are synergistic, not just additive.
Ipamorelin
Ipamorelin is a pentapeptide ghrelin mimetic and the most selective growth hormone releasing peptide available. Selective means it stimulates GH release without significantly affecting cortisol, prolactin, or aldosterone levels. That selectivity is the reason ipamorelin has become the default recommendation for GH peptide therapy in most clinical and anti-aging settings.
GHRP-2 and GHRP-6 also stimulate GH release through the ghrelin receptor, but they activate other hormonal pathways as collateral. GHRP-6 causes significant hunger. GHRP-2 can elevate cortisol. Ipamorelin avoids both. The GH release is clean.
Typical dosing is 200-300mcg administered subcutaneously 2-3 times per day. Most protocols call for injection on an empty stomach (at least 2 hours without food) to avoid blunting the GH response. The most common timing is morning (fasted) and before bed.
Ipamorelin is frequently paired with CJC-1295 (without DAC) for a synergistic effect. This combination activates both the GHRH and ghrelin pathways simultaneously, producing a larger GH pulse than either peptide alone.
For the full compound profile, dosing protocols, and research data, see the ipamorelin compound page.
CJC-1295
CJC-1295 is a synthetic GHRH analog that exists in two distinct forms, and the distinction matters.
CJC-1295 with DAC (Drug Affinity Complex) has an extended half-life of approximately 6-8 days. The DAC modification allows it to bind to albumin in the bloodstream, dramatically slowing clearance. This means a single injection can elevate GH levels for nearly a week. Dosing is typically once or twice weekly at 1-2mg per injection. The trade-off is that the sustained elevation blunts the natural pulsatile GH pattern rather than amplifying individual pulses.
CJC-1295 without DAC (also called Modified GRF 1-29) has a half-life of approximately 30 minutes. It produces a sharp, short-lived GH pulse that mirrors natural physiology more closely. This is the version most commonly used in combination with ipamorelin, dosed 1-3 times daily at 100-300mcg per injection. When clinicians refer to the "CJC/Ipamorelin stack," they almost always mean CJC-1295 without DAC.
The choice between the two forms depends on the goal. CJC-1295 with DAC is more convenient (fewer injections) but produces a less physiological GH elevation pattern. CJC-1295 without DAC requires more frequent dosing but preserves natural pulsatile release.
For the full compound profile: CJC-1295 compound page. For weight loss data on the combination: CJC-1295 + ipamorelin weight loss results.
Sermorelin
Sermorelin is a 29-amino-acid GHRH analog that represents the biologically active fragment of natural GHRH (which is 44 amino acids). It was the first GH secretagogue to receive FDA approval, approved in 1997 for the treatment of growth hormone deficiency in children under the brand name Geref.
The manufacturer voluntarily discontinued Geref in 2008 for commercial reasons, not safety concerns. Sermorelin remains available through compounding pharmacies and is one of the most prescribed GH peptides in anti-aging medicine.
As a GHRH analog, sermorelin works through the same pathway as CJC-1295. The key difference is pharmacokinetics. Sermorelin has a shorter half-life (approximately 10-20 minutes) compared to CJC-1295 without DAC (~30 minutes). This means it produces a shorter GH pulse and is typically dosed at bedtime to coincide with the natural nighttime GH surge.
Typical dosing is 200-300mcg subcutaneously at bedtime. Some protocols add a morning dose. Because of its history of FDA approval and established safety profile, sermorelin is often the first-line choice for physicians new to prescribing GH peptides.
For the full compound profile: sermorelin compound page.
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Tesamorelin
Tesamorelin is a GHRH analog that is currently FDA-approved under the brand name Egrifta for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. It is the only GH secretagogue with an active FDA approval for any indication in adults.
The mechanism is the same as sermorelin and CJC-1295 — stimulation of the GHRH receptor on the pituitary. What distinguishes tesamorelin is the clinical data behind it. Multiple Phase 3 trials demonstrated significant reduction in visceral adipose tissue (VAT), the metabolically dangerous fat that accumulates around internal organs. VAT reduction ranged from 15-18% over 26 weeks in the pivotal trials.
Tesamorelin is dosed at 2mg subcutaneously once daily. It is the highest-dose GH secretagogue in clinical use and produces the most robust and consistent GH elevation among the GHRH analogs.
Off-label use for general body composition optimization is growing, particularly in combination with GLP-1 medications. The rationale is that GLP-1 drugs drive overall weight loss while tesamorelin specifically targets visceral fat and preserves lean mass through GH-mediated protein synthesis.
For the full compound profile: tesamorelin compound page. For the weight loss stack: semaglutide + tesamorelin weight loss stack.
GHRP-2 vs GHRP-6
GHRP-2 and GHRP-6 are both hexapeptide ghrelin mimetics that stimulate GH release through the ghrelin receptor. They were among the earliest GH secretagogues studied and remain in use, though ipamorelin has largely replaced both in clinical practice due to its superior selectivity.
GHRP-6 produces a strong GH release but also significantly stimulates appetite through direct ghrelin pathway activation. This makes it popular among bodybuilders looking to increase caloric intake during bulking phases, but counterproductive for anyone trying to lose body fat. GHRP-6 also elevates cortisol and prolactin to a modest degree.
GHRP-2 produces a stronger GH release than GHRP-6 — approximately 2-3x higher peak GH levels in comparative studies. It stimulates appetite less than GHRP-6 but more than ipamorelin. It can elevate cortisol and prolactin at higher doses, though less dramatically than GHRP-6.
| Factor | GHRP-2 | GHRP-6 |
|---|---|---|
| GH release strength | Strongest among GHRPs | Strong |
| Hunger stimulation | Moderate | Significant |
| Cortisol elevation | Mild at higher doses | Mild to moderate |
| Prolactin elevation | Mild at higher doses | Mild to moderate |
| Typical dosing | 100-300mcg, 2-3x/day | 100-300mcg, 2-3x/day |
Bottom line: if maximum GH output is the goal regardless of side effects, GHRP-2 is the stronger choice. If appetite stimulation is desired (for weight gain), GHRP-6 is useful. For most people seeking clean GH elevation with minimal side effects, ipamorelin has replaced both.
Compound pages: GHRP-2 | GHRP-6
GH peptide comparison table
All six major GH secretagogues compared side by side. This table covers mechanism, GH release strength, selectivity, side effects, typical dosing, and FDA status.
| Peptide | Mechanism | GH Release | Selectivity | Key Side Effects | Typical Dosing | FDA Status |
|---|---|---|---|---|---|---|
| Ipamorelin | Ghrelin mimetic | Moderate | Highest | Minimal | 200-300mcg 2-3x/day | Research compound |
| CJC-1295 | GHRH analog | Moderate-High | High | Water retention, flushing | 100-300mcg daily (no DAC) or 1-2mg weekly (with DAC) | Research compound |
| Sermorelin | GHRH analog | Moderate | High | Injection site reactions, flushing | 200-300mcg at bedtime | Previously approved (withdrawn) |
| Tesamorelin | GHRH analog | Highest (GHRH class) | High | Joint pain, injection site reactions | 2mg once daily | FDA-approved (Egrifta) |
| GHRP-2 | Ghrelin mimetic | Highest (GHRP class) | Low | Cortisol, prolactin, moderate hunger | 100-300mcg 2-3x/day | Research compound |
| GHRP-6 | Ghrelin mimetic | High | Low | Significant hunger, cortisol, prolactin | 100-300mcg 2-3x/day | Research compound |
Structured comparison database pages:
GH peptides vs HGH
The question comes up constantly: why use peptides when you could just inject HGH directly? The answer involves biology, risk, and cost.
| Factor | GH Peptides | Exogenous HGH |
|---|---|---|
| Mechanism | Stimulates natural GH production | Injects synthetic GH directly |
| Release pattern | Pulsatile (natural) | Flat/supraphysiological |
| Pituitary suppression | Minimal to none | Can suppress natural GH production |
| Side effect risk | Lower (dose-limited by pituitary capacity) | Higher (acromegaly risk, insulin resistance, edema) |
| Cost | $100-$400/month (compounding pharmacy) | $1,000-$3,000+/month (pharmaceutical grade) |
| GH ceiling | Limited by pituitary output capacity | No natural ceiling (dose-dependent) |
Pulsatile vs constant release. The body releases GH in pulses. The largest pulse happens during deep sleep. Smaller pulses occur throughout the day, often triggered by exercise or fasting. Secretagogues amplify these natural pulses. Exogenous HGH creates a sustained, non-physiological elevation that the body did not evolve to handle continuously. Long-term supraphysiological GH levels increase the risk of insulin resistance, joint issues, and potentially abnormal tissue growth.
Pituitary suppression. When you inject exogenous GH, the pituitary receives feedback that GH levels are already elevated and reduces its own production. Over time, this can lead to dependence on exogenous GH. Secretagogues work with the pituitary, not instead of it. The feedback loop remains intact.
The cost gap. Pharmaceutical-grade HGH (brands like Norditropin, Genotropin, Humatrope) runs $1,000-$3,000+ per month depending on dose. GH peptides from compounding pharmacies typically run $100-$400 per month. This is not a marginal difference.
When HGH still makes sense. For diagnosed GH deficiency confirmed by stimulation testing, exogenous HGH replacement under endocrinologist supervision is the standard of care. For bodybuilders seeking supraphysiological GH levels beyond what the pituitary can produce, exogenous HGH is the only option. For everyone else — age-related GH decline, body composition optimization, recovery enhancement — peptides offer a more physiological approach with a better risk-to-benefit ratio.
GH peptide stacks
CJC-1295 + Ipamorelin (the classic stack)
This is the most widely prescribed GH peptide combination. CJC-1295 without DAC (GHRH analog) amplifies the GH release signal while ipamorelin (ghrelin mimetic) triggers release through a separate pathway. The result is a GH pulse significantly larger than either peptide produces alone. Typical protocol is 100-300mcg of each, injected together subcutaneously 1-3 times daily.
Detailed stack profile: CJC-1295 + ipamorelin GH optimization stack.
GH peptides + BPC-157 (recovery stack)
BPC-157 is a healing peptide with strong angiogenic and anti-inflammatory properties. Combining it with a GH peptide stack addresses recovery from two angles: GH drives protein synthesis and tissue repair at the systemic level, while BPC-157 accelerates local healing at the injury site. This combination is popular among athletes and people recovering from injuries or surgery.
GH peptides + GLP-1 medications (body composition stack)
An emerging protocol combines GH peptides (typically tesamorelin or ipamorelin/CJC-1295) with GLP-1 receptor agonists like semaglutide. The rationale: GLP-1 drugs drive significant weight loss but do not distinguish between fat and lean mass. GH peptides promote lean mass preservation and preferentially target visceral fat. The combination aims for better body composition outcomes than either approach alone.
All GH-related stacks:
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All GH secretagogue content on this site
This hub aggregates every growth hormone peptide article, comparison, and reference page on Peptide Nerds. Each article below also links back to this hub.
Compound profiles
- Ipamorelin compound profile
- CJC-1295 compound profile
- Sermorelin compound profile
- Tesamorelin compound profile
- GHRP-2 compound profile
- GHRP-6 compound profile
- Hexarelin compound profile
Blog articles
- Ipamorelin: The Complete Guide to the Selective GH Secretagogue
- CJC-1295: How the GHRH Analog Works, Dosing, and What to Expect
- Sermorelin for Anti-Aging: What the Research Actually Shows
- Tesamorelin for Fat Loss: The Only FDA-Approved GH Peptide
- MK-677 (Ibutamoren): Benefits, Risks, and What the Research Shows
- CJC-1295 + Ipamorelin Stack: The Standard GH Protocol Explained
- CJC-1295 + Ipamorelin Weight Loss Results
- GH Secretagogues vs HGH: Why Peptides Are Replacing Growth Hormone
- GLP-1 + GH Secretagogue Stack: Weight Loss and Body Composition
- When to Take Peptides: Morning or Night?
- How to Reconstitute Peptides
- Peptide Injection Sites and Rotation Guide
Comparisons
- GHRP-2 vs GHRP-6: Which Growth Hormone Peptide Is Right for You?
- GH Secretagogues vs HGH: Peptides vs Synthetic Growth Hormone
- Ipamorelin vs CJC-1295
- Tesamorelin vs Ipamorelin
- Ipamorelin + CJC-1295 vs MK-677
Stacks
- GH Optimization Stack
- CJC-1295 + Ipamorelin GH Stack
- Muscle Growth Stack: CJC-1295 + Ipamorelin + IGF-1
Tools
Related guides
Frequently asked questions
What is the best growth hormone peptide?
Ipamorelin is the most widely recommended GH peptide for most people. It is the most selective ghrelin mimetic available, meaning it stimulates growth hormone release without significantly raising cortisol, prolactin, or aldosterone. This selectivity translates to fewer side effects than GHRP-2 or GHRP-6. When paired with CJC-1295, ipamorelin produces a synergistic GH pulse that is stronger and more sustained than either peptide alone.
What is the difference between GH peptides and HGH?
GH peptides (secretagogues) stimulate your pituitary gland to produce and release its own growth hormone. HGH (human growth hormone) is synthetic, exogenous GH injected directly into the body. The key difference is that peptides preserve the natural pulsatile release pattern, while exogenous HGH delivers a flat, supraphysiological dose. Peptides carry lower risk of side effects, are significantly cheaper, and do not suppress your natural GH production the way exogenous HGH can.
Can GH peptides help with weight loss?
GH peptides contribute to fat loss primarily through increased lipolysis — the breakdown of stored fat for energy. Growth hormone is a potent lipolytic hormone that mobilizes fatty acids from adipose tissue. The effect is modest compared to GLP-1 medications but contributes to improved body composition over time, especially when combined with resistance training and adequate protein intake. Tesamorelin has the strongest direct evidence for visceral fat reduction, with FDA approval specifically for lipodystrophy-related fat accumulation.
What is the CJC-1295 and ipamorelin stack?
The CJC-1295/ipamorelin stack combines a GHRH analog (CJC-1295 without DAC) with a ghrelin mimetic (ipamorelin). CJC-1295 amplifies GH release by stimulating the GHRH pathway, while ipamorelin triggers release through the ghrelin pathway. Together they produce a larger, more sustained GH pulse than either peptide alone. This is the most commonly prescribed GH peptide combination in anti-aging and sports medicine clinics. Typical dosing is 100-300mcg of each, injected subcutaneously 1-3 times daily.
Are growth hormone peptides FDA-approved?
Sermorelin was FDA-approved for GH deficiency in children but was voluntarily withdrawn from the market by its manufacturer for commercial reasons, not safety concerns. Tesamorelin (brand name Egrifta) is currently FDA-approved for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. Ipamorelin, CJC-1295, GHRP-2, and GHRP-6 are not FDA-approved and are classified as research compounds. They are available through compounding pharmacies with a prescription in many clinics.
What time should you take GH peptides?
The most common recommendation is to take GH peptides before bed on an empty stomach (at least 2 hours after eating). This aligns with the body's largest natural GH pulse, which occurs during the first phase of deep sleep. A second dose can be taken in the morning while fasted. Food — especially carbohydrates and fats — blunts the GH response significantly, so fasting before injection is important for maximizing the effect.
What are the side effects of GH peptides?
The most common side effects across GH peptides include water retention, joint stiffness, numbness or tingling in the hands (carpal tunnel-like symptoms), and mild headaches. GHRP-6 specifically increases hunger significantly through ghrelin pathway activation. GHRP-2 can modestly elevate cortisol and prolactin at higher doses. Ipamorelin has the cleanest side effect profile of the ghrelin mimetics. Long-term safety data from large clinical trials is limited for most GH peptides except tesamorelin.
How long do GH peptides take to work?
Improved sleep quality is typically the first noticeable effect, often within the first 1-2 weeks. Improvements in skin quality, recovery from exercise, and energy levels generally appear within 4-8 weeks. Measurable changes in body composition — reduced body fat, increased lean mass — typically require 3-6 months of consistent use combined with appropriate training and nutrition. IGF-1 blood levels can be measured after 4-6 weeks to confirm the peptides are producing a physiological response.
Sources
- Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol, 1998. PMID: 9916862
- Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295. J Clin Endocrinol Metab, 2006. PMID: 16352683
- Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clin Interv Aging, 2006. PMID: 18046911
- Falutz J, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. NEJM, 2007. PMID: 18003959
- Nass R, et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults. Ann Intern Med, 2008. PMID: 18981487
- Stanley TL, et al. Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation. JAMA, 2014. PMID: 25117132
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A quick-start guide covering GLP-1 peptides, dosing basics, side effect management, and what to discuss with your doctor.
Medical disclaimer: The information on this page is for educational and informational purposes only. It is not intended as medical advice, diagnosis, or treatment. Most GH peptides discussed here are research compounds not approved by the FDA for general use. Always consult a qualified healthcare provider before starting any medication or peptide protocol. Individual results vary. See our full medical disclaimer.