Retatrutide
Contents
In short
- Retatrutide is a medicine in clinical trials that acts on three gut hormones: GIP, GLP-1 and glucagon.
- In the largest study, people in the highest dose group lost 25 per cent of their body weight in 80 weeks, compared with 4 per cent on placebo.
- Retatrutide also eased knee pain in knee osteoarthritis and reduced breathing pauses in sleep apnoea.
- Retatrutide also lowered long-term blood sugar in people with type 2 diabetes.
Fact box
- Type
- Medicine in clinical trials
- Developed by
- Eli Lilly
- Research
- Large human trials
- Other names
- retatrutide, LY3437943
What is Retatrutide?
Retatrutide is an injection taken once a week in the studies. Eli Lilly is developing it for overweight, obesity and type 2 diabetes, and it is in the last phase of clinical trials.
Retatrutide is called a triple agonist. This means it acts on the receptors for three hormones the body makes in the gut: GIP, GLP-1 and glucagon.[1][2]
GLP-1 and GIP help with feeling full and with controlling blood sugar. Glucagon affects how the body uses energy. The medicines approved today act on fewer of these receptors: semaglutide acts on GLP-1, and tirzepatide acts on GIP and GLP-1.
Retatrutide has been tested in large studies in humans and is in the last phase of clinical trials.
What does the research say about Retatrutide?
Large, controlled studies in humans show clear weight loss and better blood sugar, as well as less knee pain and fewer breathing pauses during sleep.
| Use | Studies | Research |
|---|---|---|
| Overweight and obesity | 2 studies · RCT · n = 2,677 | Large human trials |
| Type 2 diabetes | 2 studies · RCT · n = 818 | Large human trials |
| Knee osteoarthritis pain | 1 study · RCT · n = 574 | Controlled human trials |
| Sleep apnoea | 1 study · RCT · n = 243 | Controlled human trials |
| Fatty liver | 1 study · RCT · n = 98 | Early human studies |
RCT means randomised controlled trial. How to read a study
Overweight and obesity
The largest study, TRIUMPH-1, followed 2,339 adults with obesity and without diabetes for 80 weeks. Participants received retatrutide in one of three dose groups, or placebo. Body weight changed on average by −17.6, −23.7 and −25.0 per cent in the three dose groups, compared with −3.9 per cent on placebo.[1]
In the earlier phase 2 study with 338 participants, weight loss reached 24.2 per cent after 48 weeks, compared with 2.1 per cent on placebo.[2]
Type 2 diabetes
In the phase 3 study TRANSCEND-T2D-1, 537 adults with type 2 diabetes received retatrutide or placebo for 40 weeks. Long-term blood sugar (HbA1c) fell by 0.9 to 1.1 percentage points more than with placebo, and body weight fell by 11.5 to 15.3 per cent, compared with 2.6 per cent on placebo.[3]
A phase 2 study with 281 people with type 2 diabetes also showed better blood sugar and weight loss compared with placebo.[4]
Knee osteoarthritis pain
TRIUMPH-1 included a separate group of 574 people with knee osteoarthritis. Knee pain fell more with retatrutide than with placebo.[1]
Sleep apnoea
TRIUMPH-1 also included a group of 243 people with obstructive sleep apnoea. The number of breathing pauses per hour fell more with retatrutide than with placebo.[1]
Fatty liver
In a substudy with 98 people with fatty liver, the amount of fat in the liver fell markedly with retatrutide, while it stayed the same with placebo.[5]
Questions and answers about Retatrutide
Is retatrutide better than semaglutide (Ozempic) or tirzepatide (Mounjaro)?
All three have given large weight loss in their own studies. They have not yet been compared head to head in the same study, so the figures from different studies cannot be compared directly.
When will retatrutide be available?
The date is not set yet. The medicine must first be approved by the medicines agencies, and then doctors in Norway can prescribe it.
How much weight do people lose with retatrutide?
In the largest study, people in the highest dose group lost 25 per cent of their body weight on average in 80 weeks, compared with 4 per cent on placebo.