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GH Peptides/Tesamorelin vs Sermorelin
Tesamorelin · GHRH(1-44) · FDA approvedvsSermorelin · GHRH(1-29) · approved 1990, discontinued

Tesamorelin vs Sermorelin
full-length and current versus the truncated original

Last updated

Tesamorelin and sermorelin are the two GHRH analogs that actually reached FDA approval — which already sets them apart from research GHRH compounds like CJC-1295. Both stimulate the pituitary to release the body’s own growth hormone. The differences are length, indication, and whether they are still on the market.

Research reference only. Not medical advice, prescribing guidance, or a product recommendation.

At a glance

DimensionTesamorelinSermorelin
FragmentFull-length GHRH(1-44) analogGHRH(1-29) — shortest fully active fragment
ReceptorGHRH receptor (GHRHR)GHRH receptor (GHRHR)
Key modificationN-terminal trans-3-hexenoic acid (stabilized)None — the unmodified fragment
GH releaseEndogenous, feedback-preservingEndogenous, discrete physiologic pulse
FDA approvalApproved 2010 (Egrifta) — currentApproved 1990 (Geref) — discontinued commercially
Approved useExcess visceral fat in HIV-associated lipodystrophyGH-deficiency evaluation / pediatric GH deficiency (historical)
Status todayMarketed drugReferenced as a research compound
Molecular weight5135.9 Da3358 Da

Same receptor, different fragment and fate

Sermorelin is the minimalist: the first 29 residues of GHRH, the shortest piece that keeps full GH-releasing activity. It binds the GHRH receptor and prompts a short, discrete pulse of the body’s own growth hormone, preserving the natural somatostatin feedback loop. It was FDA-approved in 1990 as Geref — used to evaluate pituitary GH reserve and treat pediatric GH deficiency — but was later discontinued commercially, so today it is referenced mainly as a research compound.

Tesamorelin keeps the whole 44-residue GHRH sequence and stabilizes it with a trans-3-hexenoic acid group at the N-terminus, protecting it from rapid breakdown. That fuller, stabilized molecule is the only GHRH analog with a current FDA approval: Egrifta (2010), for reducing excess visceral abdominal fat in people with HIV-associated lipodystrophy, backed by completed Phase 3 trials. So the two bracket the GHRH-analog story — the original, truncated, now-discontinued fragment and the full-length, stabilized, still-marketed successor — with CJC-1295, the never-approved research modification of the same family, sitting between them in ambition but not in evidence.

What the comparison comes down to

Both are GHRH-receptor agonists that raise endogenous GH while preserving feedback, and both cleared FDA approval — but only tesamorelin is still on the market, with a specific visceral-fat indication and Phase 3 evidence behind it. Sermorelin is the historical original, a short GHRH(1-29) fragment approved in 1990 and since discontinued, now a research reference. For a characterized GHRH analog in current use, tesamorelin is the benchmark; sermorelin is the lineage it grew out of. This page is a research and educational reference.

Frequently asked questions

What is the difference between tesamorelin and sermorelin?+

Both are GHRH-receptor agonists that stimulate the pituitary to release growth hormone. Sermorelin is the GHRH(1-29) fragment — the shortest fully active piece — approved in 1990 (Geref) and later discontinued. Tesamorelin is a stabilized full-length GHRH(1-44) analog, FDA-approved in 2010 (Egrifta) for HIV-associated visceral fat and still marketed.

Are both FDA-approved?+

Both reached FDA approval, but only tesamorelin (Egrifta, 2010) is currently marketed. Sermorelin (Geref, 1990) was approved and later discontinued commercially. They are the two GHRH analogs to have been approved — unlike CJC-1295, which is a research compound.

Which is more physiologic?+

Both raise the body’s own GH and preserve feedback rather than supplying GH directly. Sermorelin’s short half-life produces a discrete pulse; tesamorelin is also short-acting and dosed daily. Neither creates the sustained, pulsatility-blunting elevation of a long-acting DAC-modified analog.

What is each approved for?+

Tesamorelin is approved to reduce excess visceral abdominal fat in HIV-associated lipodystrophy. Sermorelin was approved for GH-deficiency evaluation and pediatric GH deficiency before being discontinued. This page is a research and educational reference, not medical advice.

Peptide Agent

Ask the Agent: Tesamorelin vs Sermorelin

Mechanism, evidence, and trade-offs between Tesamorelin and Sermorelin — citation-backed answers grounded in PubMed, PubChem, and ClinicalTrials.gov.