Tesamorelin

Think of growth hormone like water from a tap. Injecting GH directly is like leaving the tap running flat out. Tesamorelin is more like turning the handle the body already uses, so it still flows in natural on-off pulses. But it is a properly proven, plumbed-in tap for only one specific room in the house: deep belly fat in HIV. Selling it as the answer to every other room, such as general fat loss or anti-ageing, is marketing, not evidence.

Tesamorelin is a stabilised analogue of growth hormone-releasing hormone that binds the GHRH receptor on pituitary somatotrophs, stimulating endogenous pulsatile release of growth hormone and raising IGF-1. Because it acts on the body's own GH axis rather than supplying external GH, normal somatostatin negative feedback is preserved. An N-terminal hexenoyl modification resists DPP-4 degradation, prolonging its activity. The resulting increase in GH/IGF-1 signalling promotes lipolysis, preferentially reducing visceral adipose tissue.

Research contexts. Not proven uses, and not recommendations.

Strong within its approved niche, weak everywhere else. Large randomised, double-blind, placebo-controlled Phase 3 trials showed clinically meaningful reductions in visceral adipose tissue (roughly 15-18% versus placebo) in people with HIV-associated lipodystrophy, supporting FDA approval as Egrifta in 2010 (later reformulated as Egrifta SV in 2019 and Egrifta WR in 2025). A separate, smaller randomised trial (Stanley et al., Lancet HIV 2019; NCT02196831; n=61) showed reduced liver fat with a secondary signal of less fibrosis progression in HIV-associated NAFLD. The benefit on visceral fat reverses after stopping treatment. This robust evidence is almost entirely confined to people with HIV. There is no comparable RCT base supporting tesamorelin for general fat loss, bodybuilding or anti-ageing in otherwise healthy adults.

• !Not licensed by the MHRA in the UK for any indication; any UK online supply is unlicensed and often sold as a 'research chemical' not for human use, with no quality assurance of identity, purity or sterility
• !Raises IGF-1 and GH, which can cause or worsen insulin resistance and glucose intolerance
• !Fluid retention, peripheral oedema, arthralgia and injection-site reactions reported in trials
• !Theoretical and label-cautioned concern about stimulating growth of occult malignancy; contraindicated in active cancer
• !Benefits on visceral fat are not durable and regress after the drug is stopped
• !Evidence outside the HIV-lipodystrophy population is weak; marketing for cosmetic fat loss or anti-ageing outruns the data
• !Grey-market product may not be genuine tesamorelin, or may be incorrectly formulated or non-sterile

Not licensed by the MHRA in the UK. It is approved as a prescription medicine in the US (Egrifta, Egrifta SV, Egrifta WR) for excess visceral abdominal fat in HIV-associated lipodystrophy. In the UK it would only be obtainable as an unlicensed medicinal product (such as a named-patient import under a prescriber's responsibility) or, illegitimately, via grey-market vendors selling it as a research chemical labelled "not for human consumption". Such unlicensed supply carries no guarantee of identity, purity or sterility.

• NCT02196831· Phase 2/3· Completed

  Tesamorelin Effects on Liver Fat and Histology in HIV

  Stanley et al., Lancet HIV 2019; reduced liver fat with a secondary signal of attenuated fibrosis progression in HIV-associated NAFLD (n=61).

• · Phase 3· Completed

  Pivotal Phase 3 HIV-lipodystrophy programme (Falutz et al.)

  Randomised, double-blind, placebo-controlled trials demonstrating ~15-18% visceral fat reduction; basis for FDA approval of Egrifta in 2010.

1. 01
   Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation (pivotal Phase 3 trial) — Falutz J, et al., New England Journal of Medicine (2007)

   Pivotal randomised, double-blind, placebo-controlled trial underpinning FDA approval; ~18% reduction in visceral adipose tissue versus placebo.

2. 02
   Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial — Stanley TL, et al., The Lancet HIV (2019)

   RCT (n=61) showing reduced hepatic fat fraction, with a secondary signal of attenuated fibrosis progression, in HIV-associated NAFLD (NCT02196831).

3. 03
   Egrifta (tesamorelin) US Prescribing Information / FDA approval — Theratechnologies / US FDA, Drugs@FDA (Theratechnologies; original approval 2010, Egrifta WR/F8 approved March 2025) (2010)

   Documents the approved indication (excess visceral abdominal fat in HIV lipodystrophy), warnings (IGF-1, glucose, malignancy) and contraindications.