Mod-GRF(1-29) vs Tesamorelin
A neutral, side-by-side comparison of two performance & growth hormone peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
Mod-GRF(1-29)
Mod-GRF(1-29) is a stabilized analog of growth hormone-releasing hormone (GHRH) that spans residues 1–29 of the native peptide. Unlike CJC-1295 (which includes a Drug Affinity Complex for multi-day half-life), Mod-GRF(1-29) has a short ~30-minute active window — mimicking the natural GHRH pulse pattern. It is the preferred GHRH component for precise, pulsatile GH protocols when combined with a GHRP.
Full profileTesamorelin
Tesamorelin is an FDA-approved synthetic analog of growth hormone-releasing hormone (GHRH). Approved in 2010 as Egrifta, it is the only GHRH peptide with an approved clinical indication — reduction of excess visceral abdominal fat in people with HIV-associated lipodystrophy. It has the most robust human trial evidence of any growth hormone secretagogue, including dedicated studies on visceral fat and liver fat.
Full profile| Mod-GRF(1-29) | Tesamorelin | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | Modified GRF(1-29), CJC-1295 without DAC, Tetrasubstituted GRF, Sermorelin analog | Egrifta, Egrifta SV, TH9507, GHRH analog |
| Evidence | Research-stage | FDA-approved |
| Dosing range | 100mcg–200mcg mcg, 2–3x daily, co-administered with a GHRP (pre-sleep, pre-workout, and/or upon waking) | 1.28mg–2mg mg, once daily (subcutaneous) |
| Administration | Subcutaneous injection, Intramuscular injection | Subcutaneous injection (abdomen, with site rotation) |
| Key side effects | Water retention (mild, dose-dependent), Tingling / numbness in extremities (carpal tunnel-like at high doses), Increased appetite (via GHRP component — less with Mod-GRF alone), Flushing or warmth at injection site | Injection site reactions (erythema, pruritus), Peripheral edema, Arthralgia (joint pain), Myalgia |
| Cited sources | 2 references | 5 references |
Key differences
- Evidence level differs: Mod-GRF(1-29) is research-stage, while Tesamorelin is fda-approved.
- Administration: Mod-GRF(1-29) — Subcutaneous injection, Intramuscular injection; Tesamorelin — Subcutaneous injection (abdomen, with site rotation).
- Dosing units differ: Mod-GRF(1-29) is dosed in mcg, Tesamorelin in mg — they operate at different scales.
- Frequency: Mod-GRF(1-29) is typically 2–3x daily, co-administered with a GHRP (pre-sleep, pre-workout, and/or upon waking); Tesamorelin is once daily (subcutaneous).
- Research depth: this profile cites 2 sources for Mod-GRF(1-29) vs 5 for Tesamorelin.
How each works
Mod-GRF(1-29)
Native GHRH(1-29) is rapidly cleaved by plasma dipeptidyl peptidase IV (DPP-IV) within 2–3 minutes. Mod-GRF(1-29) incorporates four amino acid substitutions (positions 2, 8, 15, 27) that resist DPP-IV degradation, extending the half-life to approximately 30 minutes while preserving GHRH receptor binding affinity. This creates a half-life window aligned with physiological GH pulsatility, making it suitable for 2–3x daily injections that mimic natural GH release patterns.
Tesamorelin
Tesamorelin stimulates pulsatile growth hormone (GH) release from the pituitary, raising serum IGF-1 and preferentially reducing visceral adipose tissue (VAT). FDA-registration trials (Falutz et al., NEJM 2007; JAIDS 2010) showed ~15% VAT reduction versus placebo over 26 weeks. Later randomized trials (Stanley et al., JAMA 2014; Lancet HIV 2019) extended the evidence to liver fat, showing meaningful reductions in hepatic fat fraction and attenuated fibrosis progression in HIV-associated NAFLD.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.