Tesamorelin peptide: what the published literature actually says about this GHRH analog

What it is. Tesamorelin (TH9507, brand name Egrifta) is a synthetic analog of human growth hormone-releasing hormone. Unlike most research peptides it keeps the full 44-residue GHRH sequence and adds exactly one thing: a trans-3-hexenoyl group on the N-terminal tyrosine. That cap sits over the spot where the enzyme DPP-4 cleaves native GHRH within minutes, which is the entire design rationale.

Where it came from. The parent hormone was isolated in 1982 by Guillemin and colleagues (Science) from a pancreatic tumor that had caused acromegaly. Theratechnologies of Montreal developed the hexenoyl-capped analog, and Falutz and colleagues published the pivotal trials in the New England Journal of Medicine (2007) and JAIDS (2010).

Regulatory record. The FDA approved tesamorelin as Egrifta on November 10, 2010 (NDA 022505) for one indication: reduction of excess abdominal fat in HIV-infected adults with lipodystrophy. It is the only GHRH analog with a current US approval. The EMA reached a negative opinion on the same data around 2011 to 2012. Reformulations followed in 2019 (Egrifta SV) and 2025 (Egrifta WR); the active peptide never changed.

How it differs from ipamorelin. Different receptor family entirely. Tesamorelin acts at the GHRH receptor (class B GPCR, Gs and cAMP). Ipamorelin is a five-residue synthetic pentapeptide at the ghrelin receptor GHS-R1a (class A, Gq). Neither engages the other's receptor, and the two have never been tested head-to-head.

Full write-ups:

• https://spartalabs.net/us/blog/tesamorelin-research-overview
• https://spartalabs.net/us/blog/tesamorelin-history
• https://spartalabs.net/us/blog/tesamorelin-vs-ipamorelin

Sparta Labs sells tesamorelin as a research reference material with per-lot COAs: https://spartalabs.net/us/products/tesamorelin

Research use only. Not for human consumption. Nothing here is medical advice.