Browse 12 growth hormone peptides tracked on Peptigrity, with verified third-party 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, mod GRF 1-29), 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.
Last updated: April 2026
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.
For 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.
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, Mod GRF 1-29) 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.
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.
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.
→ FDA peptide regulation timeline: /blog/fda-peptide-regulation-2025-2026-the-complete-timeline
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.
→ FDA peptide regulation timeline: /blog/fda-peptide-regulation-2025-2026-the-complete-timeline
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.
→ CJC-1295 with vs without DAC detailed comparison: /blog/cjc1295-vs-cjc1295-with-dac-differences
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.
→ CJC-1295 with vs without DAC detailed comparison: /blog/cjc1295-vs-cjc1295-with-dac-differences
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.
→ CJC-1295 + Ipamorelin stack protocol research: /blog/cjc1295-ipamorelin-stack-dosing-protocol-guide
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.
→ CJC-1295 + Ipamorelin stack protocol research: /blog/cjc1295-ipamorelin-stack-dosing-protocol-guide
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.
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.
→ Peptide cycling research: /blog/peptide-cycling
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.
→ Peptide cycling research: /blog/peptide-cycling
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.
→ General peptide calculator: /peptide-calculator
→ BAC water calculator: /tools/bac-water-calculator
→ General peptide dosage guide: /blog/peptide-dosage-guide
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.
→ General peptide calculator: /peptide-calculator
→ BAC water calculator: /tools/bac-water-calculator
→ General peptide dosage guide: /blog/peptide-dosage-guide