History and Development
Tesamorelin's path runs from a Canadian laboratory to an American prescription, with a firm no from Europe along the way.
A Problem Created by Success
By the late 1990s, combination HIV treatment had turned a deadly infection into a long-term condition. Doctors then began to see a new problem in some patients: fat collecting deep in the abdomen while the face and limbs grew thin. The condition was called lipodystrophy, and it raised worries about the heart as well as about how people felt in their own bodies.
TH9507 Takes Shape
Earlier research had linked this kind of belly fat to reduced growth hormone release. Theratechnologies in Montreal had been working on a stabilised form of GHRH, coded TH9507, and saw a fit. Raising growth hormone through the pituitary looked safer than injecting the hormone itself.
Two Large Trials
Two phase 3 trials enrolled more than 800 adults with HIV at clinics in several countries. Their first results appeared in The New England Journal of Medicine in 2007. Visceral fat fell, blood fats improved and, after a year, the gains held as long as treatment continued.
US Approval as Egrifta
On 10 November 2010 the US Food and Drug Administration approved tesamorelin, sold as Egrifta, to reduce excess abdominal fat in people with HIV and lipodystrophy. It was the first medicine approved for this purpose. EMD Serono, part of Germany's Merck KGaA group, handled sales in the US at first.
Europe Says No
The Spanish firm Ferrer applied to the European Medicines Agency in May 2011. Reviewers asked whether a smaller waist really meant better health, questioned the cut-off used to pick patients and worried about high IGF-1 levels and the lack of long-term safety data. Ferrer withdrew the application on 21 June 2012.
New Versions and a New Owner
Health Canada approved Egrifta in April 2014. In 2018 a new US version, Egrifta SV, came with different mixing and storage instructions, and in March 2025 the FDA approved Egrifta WR, a further formulation that is gradually replacing it. In September 2025 Theratechnologies was bought by an affiliate of Future Pak, a privately held US drug manufacturer.