Most research peptides never leave the lab. Tesamorelin is the rare exception — and that’s exactly why researchers find it so interesting.
Tesamorelin is unusual among research peptides for one simple reason: it has a real clinical track record. While most compounds in this space live entirely in preclinical research, tesamorelin went the whole distance and earned regulatory approval — which makes it a genuinely useful reference point.
What it is
It’s a synthetic version of growth hormone-releasing hormone (GHRH) — the natural signal your pituitary gland listens for before it releases growth hormone. Native GHRH breaks down almost immediately in the body, so tesamorelin carries a small chemical modification on one end of the molecule that makes it far more stable while keeping the exact shape the GHRH receptor recognises. Same message, much longer-lasting.
The part researchers find interesting
In 2010 tesamorelin became the first — and to date only — GHRH analogue to gain full FDA approval, marketed as Egrifta and indicated to reduce excess visceral abdominal fat in a specific patient group.
That visceral-fat finding is the headline: in the published trials it lowered visceral adipose tissue — the deep fat around the organs — by a meaningful margin over roughly six months.
The mechanism is what makes it elegant. Rather than flooding the body with external growth hormone, tesamorelin nudges the pituitary to release its own hormone in natural pulses, which then raises IGF-1. Because the body’s feedback loop stays intact, it behaves very differently from injecting growth hormone directly — and that’s why it has since been explored in research well beyond its original approval, including liver fat (NAFLD) and lipid markers.
How it sits among the GHRH peptides
Tesamorelin is the clinically-validated, full-length GHRH analogue. CJC-1295 is the one usually reached for when researchers want an extended half-life, often paired with a GHRP like Ipamorelin — which acts on a completely different receptor. Different tools for different questions.
Handling in the lab
Supplied as a lyophilised powder in a sterile 10mg vial, reconstituted with bacteriostatic water and kept refrigerated once mixed. The current UK-warehoused batch tests at 99.120% by HPLC, with the Janoshik certificate published on the product page.
In the catalogue
Tesamorelin
Stocked in our UK warehouse at ≥99% HPLC purity, Janoshik independently tested.
