Tesamorelin Research Peptide

What Is Tesamorelin?

Tesamorelin is the full 44-amino-acid sequence of human growth hormone-releasing hormone, GHRH(1-44), with one modification: a trans-3-hexenoyl group attached to the tyrosine at position 1. Natural GHRH lasts only minutes because the enzyme DPP-IV cuts the bond between its first two amino acids. The hexenoyl cap blocks that cut, so tesamorelin survives far longer while binding the GHRH receptor much like the natural hormone.

That modification turned a research compound into an approved drug. Theratechnologies developed tesamorelin under the code TH9507, and on November 10, 2010, the FDA approved it as Egrifta to reduce excess abdominal fat in HIV-infected patients with lipodystrophy. The approval rested on multiple randomized, placebo-controlled Phase 3 trials. Tesamorelin is the only GHRH analog currently approved in the US. The research-grade tesamorelin sold here is not that drug.

In research, tesamorelin is used as a stable, well-characterized GHRH-receptor agonist for studying pituitary signaling, pulsatile growth hormone release and the downstream IGF-1 axis. It is often compared with sermorelin, the shorter, unmodified GHRH fragment; see Sermorelin vs Tesamorelin and our Sermorelin page.

This product is strictly for research purposes only. Not approved for human or animal use.

Key Characteristics

Molecular Profile

Physical Properties

Tesamorelin in Published Research

Because Egrifta went through full FDA registration, tesamorelin has substantially more peer-reviewed human data than most research peptides. Its Phase 3 trials reported significant reductions in visceral adipose tissue over 26-week periods, along with sustained increases in IGF-1. Those studies also documented its pharmacology and safety profile in detail, which is why tesamorelin is a common benchmark in GHRH-analog research.

Later studies built on that foundation, examining tesamorelin in liver fat research and in cognitive-function studies in older adults. Mechanistic work has focused on the hexenoyl modification itself: how blocking DPP-IV cleavage extends the peptide’s activity while leaving receptor binding essentially unchanged.

Researchers studying the growth hormone axis often pair a GHRH analog with a ghrelin-receptor agonist, since the two act on the same pituitary cells through separate routes. We supply that pairing as the Tesamorelin + Ipamorelin blend.

Frequently Asked Questions

What is Tesamorelin approved for?

As the drug Egrifta, tesamorelin is FDA-approved to reduce excess abdominal fat in HIV-infected patients with lipodystrophy. Research-grade tesamorelin is not that drug and is sold for laboratory use only.

How is Tesamorelin different from natural GHRH?

It has the same 44-amino-acid sequence plus a trans-3-hexenoyl group on the first amino acid. That cap blocks the enzyme that normally breaks GHRH down within minutes.

What is the difference between Tesamorelin and Sermorelin?

Tesamorelin is the full 44-residue GHRH with a stabilizing cap. Sermorelin is the unmodified first 29 residues. Tesamorelin is a currently approved drug; sermorelin’s branded product, Geref, was discontinued in 2008.

What did the Phase 3 trials show?

Significant reductions in visceral adipose tissue over 26 weeks and sustained IGF-1 elevation, in HIV-infected patients with lipodystrophy.

What sizes is Tesamorelin available in?

5 mg and 10 mg options. Each kit contains 10 vials, verified by HPLC and mass spectrometry, with the lot COA available on request. Learn how to read a peptide COA.

How should Tesamorelin be stored?

Refrigerated at 2–8 °C (36–46 °F), sealed, dry and away from light. For long-term storage, −20 °C. Tesamorelin contains methionine, which oxidizes easily, so keep vials tightly sealed.