Tesamorelin is a synthetic analog of growth-hormone-releasing hormone (GHRH) that stimulates the pituitary to release endogenous growth hormone in pulses. It is FDA-approved as Egrifta for HIV-related lipodystrophy. In research it is most-studied for visceral-adipose-tissue reduction and downstream IGF-1 effects.
Research notes
How does Tesamorelin work?
Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH) stabilized against rapid enzymatic degradation. Unlike direct exogenous growth hormone, tesamorelin works upstream — it stimulates the pituitary to release GH in the body's natural pulsatile pattern, which preserves the negative-feedback loops that regulate the GH–IGF-1 axis.
This mechanism distinguishes tesamorelin from related GH-axis compounds. Direct exogenous human growth hormone (hGH) bypasses the pituitary entirely; ghrelin-receptor agonists (ipamorelin, MK-677) act on a different receptor family. Tesamorelin specifically activates GHRH receptors.
The compound is FDA-approved as Egrifta for HIV-associated lipodystrophy (visceral fat reduction). Research-protocol use outside that indication is what most vendor catalog listings target.
What dose is approved?
The approved Egrifta dose is 2 mg once daily by subcutaneous injection, for HIV-associated lipodystrophy, under a prescriber (label). We do not publish doses for use outside that indication.
Half-life is short: the 2010 Egrifta label gives a mean elimination half-life of 26 minutes in healthy subjects and 38 minutes in HIV-infected patients after 14 days of daily injection (label). The 2025 Egrifta WR label gives 11 minutes after a single dose of the newer formulation. The pituitary response continues for several hours after the peptide itself has been cleared.
What are the known side-effect concerns?
Reported side effects from clinical and research-protocol literature cluster in three categories:
- Injection-site reactions — most-reported; generally mild
- Joint stiffness / mild edema — reported in the Egrifta trials and listed on the label
- Glucose tolerance changes — modest; monitored in clinical trials
What does this guide cover?
Vendor audits for tesamorelin focus on identity confirmation and purity at scale. The compound is structurally complex (44 amino acids), and lower-quality synthesis routes produce truncated peptide fragments that show up on HPLC as secondary peaks. We weight the per-batch HPLC chromatogram heavily for tesamorelin specifically.
What trials are running now?
Beyond the original Egrifta approval trials, academic groups keep testing tesamorelin in new settings. As of 13 October 2026:
| Trial | Phase, size | Status |
|---|---|---|
| NCT06554717, with exercise to improve physical function in HIV (Massachusetts General Hospital) | Phase 2, 100 | Recruiting |
| NCT03150511, recovery after peripheral nerve injury (Johns Hopkins) | Phase 2, 36 | Recruiting |
| NCT03375788, fatty liver disease (Massachusetts General Hospital) | Phase 2, 51 | Completed. Results posted November 2025 |
| NCT02572323, cognition in older adults with HIV (UC San Diego) | Phase 2, 73 | Completed. Results posted March 2026 |
A 2026 record for a tesamorelin liver-fat trial (NCT07481734) is titled "(Mock Study)" and belongs to a set of eight registrations that should not be cited.
What it's researched for
- visceral fat reduction
- GHRH analog research
- HIV-associated lipodystrophy (FDA-approved indication)
Where to source it
ALL 13 VENDORS →RANKED BY COMPOSITE SCORE · PRICES ARE SNAPSHOTS FROM THE PRICE INDEX · PER-MG IS A WITHIN-COMPOUND COMPARATOR
Frequently asked about Tesamorelin
What is tesamorelin?
Tesamorelin is a synthetic 44-amino-acid analog of growth-hormone-releasing hormone (GHRH). It binds the GHRH receptor on pituitary somatotrophs and stimulates pulsatile release of endogenous growth hormone, rather than introducing exogenous HGH directly.
How is tesamorelin different from HGH?
HGH is exogenous growth hormone administered directly; tesamorelin stimulates the body to release its own HGH in physiologic pulses. The pulsatile pattern is closer to natural GHRH signaling than continuous HGH administration, which may reduce some side effects associated with sustained HGH levels.
Is tesamorelin FDA-approved?
Yes — tesamorelin is FDA-approved as Egrifta for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. It is not approved for general weight loss, anti-aging, or athletic-performance indications. Research-grade tesamorelin sold by peptide vendors is the same molecule but is not pharmaceutical-grade.
What doses are used in tesamorelin research?
The FDA-approved protocol for HIV-lipodystrophy is 2 mg subcutaneous daily. On half-life, the 2010 Egrifta label gives a mean elimination half-life of 26 minutes in healthy subjects and 38 minutes in HIV-infected patients after 14 days of daily injection; the downstream GH pulse is the operative mechanism.
What is the typical purity of research-grade tesamorelin?
In the 2,087-result lab record behind our [purity study](/articles/peptide-purity-fill-2087-lab-results) (Kovera, Janoshik and four vendor-published sets, duplicates counted once), tesamorelin has 96 results from 62 clients. Median HPLC purity across 92 results that report one was 99.89% and the lowest 98.22%. Of 89 results with a measured content, 1 held under 90% of label; the median was 109.1%. Two Kovera certificates failed identity, both in May 2026. These are results vendors chose to publish, not a random sample.