First large trial
In a trial of 412 adults with HIV and extra belly fat, deep belly fat fell about 15% with tesamorelin and rose about 5% with a dummy shot over 26 weeks.
Evidence without hype
What the main trials actually found
The clearest evidence is for deep belly fat in adults with HIV and lipodystrophy. That is not the same as broad weight loss.
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Main findings
The figures below describe trials. They are not treatment directions.
Second large trial
In another trial of 404 adults, deep belly fat fell about 11% with tesamorelin and less than 1% with a dummy shot over about six months.
After stopping
In both trials, people switched to a dummy shot after 26 weeks regained the deep belly fat over the next 26 weeks.
Body weight
The main trials showed little change in body weight. As of September 2026, the label said tesamorelin was not for weight-loss management.
Checklist
How to read those results
A percentage alone does not answer every personal question.
Population
The main trials enrolled adults with HIV and extra belly fat.
Outcome
They measured deep fat around the organs, not only a scale reading.
Time
The main comparison lasted months, while long-term heart and blood-vessel safety remains unknown.
Durability
The benefit faded when people stopped taking it during the second half of each trial.
Fit
A result in this group does not prove the same result for ageing, memory, or general weight loss.
The label says the prescriber should rethink whether to keep going if deep belly fat does not go down.