Growth hormone peptides, cross-examined.
12 growth hormone peptides tracked on Peptigrity, with independent HPLC purity data, shop coverage and mechanism research for each. The category covers four mechanism classes: GHRH analogs that stimulate pituitary GH release (tesamorelin, sermorelin, CJC-1295), ghrelin receptor agonists that work synergistically with GHRH (ipamorelin, GHRP-2, GHRP-6, hexarelin), modified IGF-1 variants (IGF-1 LR3, IGF-1 DES) that act downstream of GH, and PEG-MGF, a stabilized mechano growth factor for muscle repair contexts.
Figures updated
How to choose between growth hormone peptides
Growth hormone peptides operate through four distinct mechanism classes. GHRH analogs and ghrelin agonists work upstream - they stimulate the pituitary to release endogenous GH. IGF-1 variants and MGF act downstream - they substitute for or augment GH's tissue-level effects. The classes are commonly stacked rather than used in isolation.
GHRH analogs
Tesamorelin, Sermorelin, CJC-1295 (with DAC), CJC-1295 (without DAC)
Pituitary GHRH receptor agonism
Human RCT (tesamorelin) · Preclinical/limited clinical (others) · Tesamorelin FDA-approved · Others research-onlyGhrelin receptor agonists (GHS)
Ipamorelin, GHRP-2, GHRP-6, Hexarelin
GHS-R1a agonism, ghrelin pathway
Preclinical · Limited human data · Research-onlyMechano growth factor
PEG-MGF
IGF-1 splice variant, satellite cell activation
Preclinical · Research-onlyFor the most common buyer question in this category - which CJC-1295 to choose - see the CJC-1295 with DAC vs without DAC comparison. For the canonical GHRH + GHS stack research, see the CJC-1295 + Ipamorelin stack protocol guide.
Compounds in this category
Growth Hormone prices →| Compound | Avg purity | Lab tests | Shops listing it |
|---|---|---|---|
Synthetic growth hormone-releasing hormone (GHRH) analog, FDA-approved as Egrifta® for HIV-associated lipodystrophy. Researched for visceral fat reduction. | 99.4% | 578 | 458 |
Selective growth hormone secretagogue (GHS) that stimulates pulsatile GH release with minimal effects on cortisol and prolactin. | 99.7% | 452 | 452 |
Modified growth hormone-releasing hormone (GHRH) analog for pulsatile GH release. Also known as Mod GRF (1-29). Shorter half-life than the DAC version. | 99.5% | 302 | 346 |
Synthetic 29-amino acid GHRH analog, the first FDA-approved GH-releasing peptide (Geref®). Stimulates natural pulsatile GH secretion from the pituitary. | 99.4% | 231 | 329 |
Modified insulin-like growth factor-1 with extended half-life (20+ hours). Researched for muscle growth, recovery, and cell proliferation. | 98.6% | 144 | 324 |
GHRH analog with a Drug Affinity Complex that extends half-life to 6-8 days, producing sustained GH elevation from a single weekly injection. | 99.2% | 119 | 276 |
Synthetic hexapeptide GH secretagogue that strongly stimulates growth hormone release and appetite via the ghrelin receptor. | 99.3% | 48 | 215 |
Synthetic hexapeptide growth hormone secretagogue that stimulates GH release via the ghrelin receptor. Stronger GH response than GHRP-6 but with moderate appetite effects. | 99.2% | 39 | 198 |
PEGylated mechano growth factor — a modified IGF-1 splice variant with extended half-life, researched for muscle repair and satellite cell activation. | 99.4% | 29 | 148 |
Synthetic hexapeptide GH secretagogue with the strongest growth hormone release of any GHRP. Also researched for cardiac tissue protection. | 99.0% | 26 | 167 |
Truncated IGF-1 variant missing the first 3 amino acids, resulting in reduced IGFBP binding and enhanced local anabolic potency. | 99.0% | 4 | 104 |
| No lab tests yet · 1 compound | |||
MK-677Not a peptide Orally active, non-peptide ghrelin-receptor (GHSR-1a) agonist and growth hormone secretagogue developed by Merck, researched for sustained GH and IGF-1 elevation, body composition, bone density, and sleep. | — | Submit one → | 62 |
Lab tests link to each compound's lab-test page. Purity dots: ≥98% green · 95–98% purple · 90–95% amber · under 90% red (the /lab-tests bands). “Shops listing it” counts shops that list the compound, tested or not.
Mechanism overview
Growth hormone peptides act on three different points in the GH/IGF-1 axis: pituitary GH release (GHRH analogs and ghrelin agonists), tissue-level IGF-1 receptor activation (IGF-1 variants), and satellite cell recruitment in damaged muscle (MGF).
The growth hormone axis is layered. The hypothalamus releases GHRH (growth hormone-releasing hormone) and the gut releases ghrelin - both stimulate the anterior pituitary to release growth hormone (GH) in pulses. GH then acts on the liver (driving systemic IGF-1 release), on adipose tissue (lipolysis), and on muscle and bone (anabolic signaling). Most of GH's tissue-level effects are actually mediated by IGF-1 - which is why IGF-1 receptor agonists can substitute for some GH effects without needing to involve the pituitary at all.
GHRH analogs (tesamorelin, sermorelin, CJC-1295) restore or enhance the upstream signal. They preserve the natural pulsatile pattern, which is important - continuous GH elevation is associated with side effects (joint pain, insulin resistance, organ growth), while pulsatile elevation generally is not. CJC-1295 with DAC is an exception: the long half-life produces sustained rather than pulsatile elevation, which is why it sits in a different research-frame than the other GHRH analogs.
Ghrelin receptor agonists (ipamorelin, GHRP-2, GHRP-6, hexarelin) work through the parallel ghrelin pathway. The synergy between GHRH and ghrelin signaling is multiplicative rather than additive: combining a GHRH analog with a GHS produces substantially more GH release than either alone. This is why CJC-1295 + ipamorelin stacks are the most common research protocol in this category - they exploit the multiplicative effect with the cleanest side-effect profile (ipamorelin has minimal cortisol or prolactin elevation, unlike the other GHS).
IGF-1 variants and MGF act downstream entirely. IGF-1 LR3 produces systemic IGF-1 receptor activation; IGF-1 DES produces localized effect at injection sites; PEG-MGF specifically recruits satellite cells in damaged muscle. These are mechanistically distinct from GHRH/GHS research and are usually researched for different goals.
For deeper background on growth hormone peptide research, see the CJC-1295 + Ipamorelin stack protocol guide.
⚠ Quality verification: growth hormone peptides have category-specific risks
Three quality risks apply specifically to growth hormone peptides:
CJC-1295 form ambiguity: "CJC-1295" is sold in two forms - with DAC (long-acting) and without DAC (short-acting, identical to Mod GRF 1-29). Some vendors do not clearly distinguish them on labels. Mass spectrometry identifies which form is actually in the vial: CJC-1295 with DAC has a higher molecular weight than the without-DAC form due to the lipid attachment.
Sequence drift in synthesis: GHRH analogs are 29-30 amino acid peptides with substituted residues (Mod GRF 1-29 has four substitutions versus native GHRH 1-29). Synthesis errors that swap a single amino acid produce a non-functional or partially functional product that still passes HPLC purity tests. Mass spectrometry molecular-weight verification is essential for this class.
IGF-1 LR3 vs IGF-1 vs IGF-1 DES confusion: The three forms have similar appearances and are sometimes mislabeled. Native IGF-1 (which buyers generally aren't trying to purchase) has a much shorter half-life than LR3, while DES has different anabolic kinetics entirely. Verify the specific form via mass spec.
Frequently asked questions
One. Tesamorelin is FDA-approved as Egrifta for HIV-associated lipodystrophy specifically - not for general weight loss, anti-aging, or performance use. Sermorelin was previously FDA-approved as Geref but was withdrawn; it remains used in compounding pharmacy contexts in some jurisdictions. None of the other 10 compounds in this category have FDA approval. All are investigational research compounds in Western jurisdictions.
The DAC (Drug Affinity Complex) is a lipid attachment that allows the peptide to bind albumin in circulation, extending half-life from minutes to 6-8 days. CJC-1295 with DAC produces sustained, non-pulsatile GH elevation - a different physiological state than the natural pulsatile pattern. CJC-1295 without DAC has a short half-life and preserves pulsatile release; it is functionally identical to Mod GRF 1-29 (same molecule, different research-community names). The two forms are not substitutes - choose based on whether sustained or pulsatile elevation is the research goal.
GHRH and ghrelin act on the pituitary through different receptors and their effects are multiplicative rather than additive. Combining a GHRH analog (CJC-1295 without DAC, sermorelin, mod GRF 1-29) with a ghrelin receptor agonist (ipamorelin, GHRP-2) produces substantially more GH release than the same dose of either alone. The CJC-1295 + ipamorelin combination is the most-researched stack in this category because ipamorelin has the cleanest side-effect profile of the GHS class - minimal cortisol or prolactin elevation versus GHRP-6 or hexarelin.
Multiple compounds in this category are WADA-prohibited. Growth hormone itself is on the WADA Prohibited List under class S2 (peptide hormones). GHRH analogs (sermorelin, tesamorelin, CJC-1295), ghrelin receptor agonists (ipamorelin, GHRP-2, GHRP-6, hexarelin), and IGF-1 variants all fall under S2 as GH-releasing or GH-mimicking compounds. Athletes in WADA-tested sports should treat any compound in this category as likely prohibited. WADA updates the list annually each January - verify the current year's classification.
Yes - that's the mechanism. GHRH analogs and ghrelin agonists raise GH, which raises liver IGF-1 production. IGF-1 LR3 raises systemic IGF-1 receptor activation directly. Sustained elevated IGF-1 has documented research associations with insulin resistance, increased cell proliferation rates, and theoretical (not confirmed) cancer risk implications from long-term elevation. Most research protocols use cycled rather than continuous administration. None of these compounds have long-term safety data in healthy users from controlled trials.
Dosing varies dramatically by compound and protocol goal. Most GHRH analogs and GHS are dosed in micrograms (mcg) rather than milligrams, typically 100-300 mcg per injection in research protocols. CJC-1295 with DAC is dosed weekly due to long half-life; CJC-1295 without DAC and Mod GRF 1-29 are dosed multiple times daily for pulsatile effect. IGF-1 LR3 and DES use different dosing logic again. Use the general peptide calculator for any compound, plus the BAC water calculator for reconstitution math.
This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.