Growth hormone axis
Tesamorelin vs Ipamorelin: Research Comparison
Tesamorelin and ipamorelin both lead to growth hormone release from the pituitary, through different receptors. Tesamorelin is a GHRH analogue that acts on the GHRH receptor. Ipamorelin is a five-amino-acid peptide that acts on the ghrelin receptor.
Side-by-side comparison
| Attribute | Tesamorelin | Ipamorelin |
|---|---|---|
| What it is | Full 44-amino-acid GHRH analogue with a hexenoyl group | Synthetic five-amino-acid peptide |
| Receptor | GHRH receptor | Ghrelin receptor (GHS-R1a) |
| Developer | Theratechnologies | Novo Nordisk |
| Human data | Two phase 3 placebo-controlled trials in more than 800 people with HIV | Pharmacokinetic study in healthy men; phase 2 trial after bowel surgery found no clear difference from placebo |
| Licensed status | Licensed in the US since 2010 for one use in people with HIV; not licensed in the UK or EU | Not licensed |
Detailed analysis
Tesamorelin binds the GHRH receptor on growth-hormone-producing cells and triggers the body's own growth hormone release, which raises IGF-1. Its hexenoyl group makes it resistant to the enzyme DPP-4 (Ferdinandi et al., 2007). The US FDA approved it in 2010 for one use in adults with HIV-associated lipodystrophy, based on two phase 3 placebo-controlled trials (Falutz et al., 2007 and 2010). It is not licensed in the UK or EU, and the US label states that long-term cardiovascular safety has not been established.
Ipamorelin acts on the ghrelin receptor. In pigs it released growth hormone without raising ACTH or cortisol (Raun et al., 1998), and in healthy men its half-life was about two hours (Gobburu et al., 1999). A phase 2 placebo-controlled trial in 114 adults after bowel surgery found no clear difference from placebo (Beck et al., 2014).
Tesamorelin's human trials are in one patient group, people with HIV. Ipamorelin's published human data come from two studies.
Key differences
- ·Tesamorelin acts on the GHRH receptor; ipamorelin acts on the ghrelin receptor.
- ·Tesamorelin has phase 3 trials in people with HIV; ipamorelin has a pharmacokinetic study and one phase 2 trial.
- ·Tesamorelin is licensed in the US for one use; ipamorelin is not licensed.
Research summary
Tesamorelin has animal studies and phase 3 human trials in people with HIV (Falutz et al., 2007). Ipamorelin has pig and rat studies (Raun et al., 1998) and two human studies. Neither has long-term safety data beyond these trials. Supplied for laboratory research use only.