What tesamorelin is
Tesamorelin is a synthetic analogue of growth hormone-releasing hormone. Rather than supplying growth hormone directly, it stimulates the pituitary to release its own, which preserves the natural pulsatile release pattern and the feedback loops that regulate it.
It is approved by the FDA as Egrifta for the reduction of excess visceral abdominal fat in adults with HIV-associated lipodystrophy — a specific metabolic complication seen in people on long-term antiretroviral therapy.
The indication is the whole story
United States: FDA-approved, for HIV-associated lipodystrophy only.
United Kingdom: not licensed. Tesamorelin holds no UK marketing authorisation for any indication, and cannot be lawfully supplied here for human use.
Approval for a narrow indication is not general endorsement. The phase 3 trials enrolled people with a defined pathology, measured a defined endpoint, and were reviewed on that basis. What they demonstrate is that tesamorelin reduces visceral adipose tissue in that population.
A drug approved for one condition in one group of people has not been shown to be useful, or safe, in a different group with a different goal.
The grey market sells tesamorelin for general fat loss, body recomposition and anti-ageing. None of those are the studied indication, and the population most likely to buy it — healthy adults with normal growth hormone axes — is not the population it was tested in.
What growth hormone stimulation actually does
Raising growth hormone and IGF-1 is not uniformly beneficial. The relevant concerns are well established in endocrinology rather than speculative:
- Glucose handling. Growth hormone opposes insulin action. Elevated GH can worsen insulin resistance and raise blood glucose, which is documented in tesamorelin's own trial data.
- Fluid retention, joint pain and carpal tunnel symptoms. Recognised effects of GH axis stimulation.
- IGF-1 and proliferation. IGF-1 is a growth signal. Sustained elevation in people without a deficiency is not an established-safe intervention, and this is why licensed GH-axis drugs carry monitoring requirements.
In the approved setting, IGF-1 is monitored and the drug is used under specialist care in people with a genuine indication. Neither applies to unsupervised use.
The grey-market layer
Egrifta is a manufactured pharmaceutical with verified content. Vials sold online as tesamorelin are not that product, whatever the label says. Peptide identity, purity, quantity and sterility are all unverified, and growth hormone secretagogues are a category where mislabelled and underdosed material is common.
Where this leaves you
Tesamorelin is a real drug with real evidence in a real clinical population. If you are outside that population, the trial data does not tell you what will happen — it tells you what happened to people with a different physiology and a different problem.