Tesamorelin (Egrifta)

What Tesamorelin is

Tesamorelin is a stabilized analog of growth hormone-releasing hormone (GHRH). It stimulates the pituitary gland to release the body’s own growth hormone in natural pulses, and thereby raises IGF-1. Because the body’s own feedback loop is preserved, the approach is considered more physiological than supplying growth hormone from outside.

The approved purpose is the reduction of visceral fat, that is, the deep abdominal fat between the organs, in HIV-associated lipodystrophy. This is a fat distribution disorder under antiretroviral therapy, not overweight in the usual sense.

The target group of the studies and the target group of the marketing

All efficacy data come from a single population: people with HIV and fat accumulation in the abdomen. The evidence reviewed contains no controlled study in healthy people without lipodystrophy. Yet the substance is marketed to exactly this group: for body composition, recovery and anti-aging.

Hard endpoints have not been studied either. What was measured were fat areas, waist circumferences and liver fat fractions, that is, imaging and laboratory measures. Whether these translate into fewer heart attacks, fewer cases of diabetes or a longer life is open. This is exactly where the European regulators’ criticism also started.

What the studies show

Second pivotal trial: 404 participants over twelve months

The second of the two pivotal trials randomized 404 HIV patients with fat accumulation in the abdomen in a 2:1 ratio to 2 mg daily subcutaneously or placebo, over twelve months. After six months, visceral fat area had fallen by 10.9 % or 21 cm², compared with 0.6 % under placebo. Over the entire course of the study, the authors put the reduction at about 18 %. Blood glucose remained unremarkable. In the extension phase participants were randomized again; those switched to placebo lost the effect again.

Meta-analysis: fat reduction confirmed, magnitude inconsistent

A meta-analysis of four randomized trials with 909 participants found minus 21.47 cm² for visceral fat area (95 % CI -34.73 to -8.22), p=0.002, with a heterogeneity of I²=74 %. Waist circumference fell by 1.61 cm (-2.28 to -0.95) with I²=0 %, that is, very consistently across the studies. With a relative risk of 2.25 (0.98 to 5.17, p=0.06), the dropout rate was numerically more than twice as high as under placebo, without statistical significance.

Liver fat: the absolute figure

A randomized, double-blind study with 61 participants, divided evenly between two arms, examined liver fat fraction over twelve months. The difference from placebo was 4.1 percentage points absolute (95 % CI -7.6 to -0.7, p=0.018). Percentages for liver fat are often communicated as relative change, which makes the same measurement look considerably larger. The difference between relative and absolute effect is decisive here for putting the result in context.

Where the data stop

• Effect in healthy people without lipodystrophy. No controlled study was found for this group. Transferring the HIV data is an assumption, not a finding.
• A clinically meaningful benefit of the fat reduction. This is exactly what the responsible EMA committee objected to as not demonstrated. Areas and fractions were measured, not disease outcomes.
• A benefit for skin, recovery or anti-aging. These endpoints were not investigated in any of the studies reviewed.
• Long-term safety. Missing long-term safety data were one of the five objections with which the European assessment ended.

Status, approval and legal

In the US, tesamorelin is approved as Egrifta for the reduction of visceral abdominal fat in HIV-associated lipodystrophy, and only for that. Since March 2025 there has also been Egrifta WR, which only needs to be mixed once a week. According to the US prescribing information, long-term cardiovascular safety has not been established, and tesamorelin is not intended for weight loss. In Germany, no tesamorelin product is approved; the substance is listed in the annex to the German Anti-Doping Act. In sport it is prohibited at all times, in competition and in training (WADA list 2026, S2.2.4).

There is no approval in the EU. Ferrer Internacional withdrew the EU marketing authorization application on 2012-06-26 after the CHMP had not seen a positive benefit-risk balance. The five objections are the most informative part of the record: first, the reduction in fat area had not been demonstrated to be a clinically meaningful benefit; second, the population studied was not representative of European HIV patients; third, permanently elevated IGF-1 levels were a significant safety concern, specifically because of cancer risk and diabetic eye disease; fourth, long-term safety data were lacking; fifth, excess abdominal fat due to lipodystrophy could hardly be distinguished from overweight in practice.

Safety

In the second pivotal trial, blood glucose remained unremarkable. In the meta-analysis, the dropout rate under tesamorelin, with a relative risk of 2.25 (0.98 to 5.17), was numerically more than twice as high as under placebo, but at p=0.06 it missed significance. Fluid retention and joint complaints come into question as class effects of growth hormone; blood glucose should be kept in view.

The most serious documented objection concerns not an observed event but an assessment: the CHMP classified permanently elevated IGF-1 levels as a significant safety concern, citing cancer risk and diabetic eye disease. Long-term data that could settle this question were not available.

Sources

• Falutz et al. 2010, J Acquir Immune Defic Syndr – pivotal trial, 404 participants, 12 months (PMID 20101189)
• Stanley et al. 2019, The Lancet HIV – randomized, double-blind, liver fat, n=61 (PMID 31611038)
• Meta-analysis 2026, J Int Assoc Provid AIDS Care – 4 RCTs, 909 participants (PMID 42538058)
• EMA – Ferrer Internacional withdraws the marketing authorization application for Egrifta (tesamorelin), June 26, 2012
• DailyMed – US prescribing information Egrifta WR (tesamorelin)