Retatrutide: a new treatment being studied for obesity
There has been exciting news in obesity medicine. A new medicine called Retatrutide has shown very strong weight loss results in a large clinical trial called TRIUMPH-1.
Retatrutide is a once-weekly injection. It is not available for routine use yet. At the moment, it is still being tested in clinical trials. This means doctors cannot prescribe it in normal clinics yet.
However, the results are important because they show how quickly obesity treatments are improving.
What is Retatrutide?
Retatrutide is a medication which works by copying the actions of natural hormones in the body. These hormones help control hunger, fullness, cravings, how the body uses energy and handles sugar and fat
Retatrutide is sometimes called a triple hormone medicine because it works on three hormone pathways: GLP-1, GIP and glucagon. You may have heard of medicines such as Wegovy or Mounjaro. These medicines also work through hormone pathways. Retatrutide goes one step further by working on three pathways at the same time.
What did the TRIUMPH-1 study show?
The TRIUMPH-1 trial studied adults living with obesity, or people who were overweight and had a weight-related health problem.
After 80 weeks, people taking Retatrutide lost a large amount of weight. The average weight loss was 19& with the 4mg dose, 25. 9% with the 9 mg dose and 28.3% with the 12 mg dose compared with 2.2% with placebo, or a dummy treatment. People taking the highest dose lost around 70 lb, or just over 31 kg, on average.
Almost half of the people taking the highest dose lost at least 30% of their body weight. This is a very large amount of weight loss. In the past, this level of weight loss was usually only seen after weight loss surgery.
In a longer part of the study, people with a starting BMI of 35 or above continued treatment for up to 2 years. Those taking the highest dose lost around 30.3% of their body weight, which was about 85 lb, or 38.5 kg, on average.
Why is this important?
Obesity is not simply about eating too much or moving too little.
Obesity is a long-term medical condition. It is affected by hormones, genes, appetite signals, sleep, stress, medications, other health problems and the world we live in.
Many people living with obesity have tried very hard to lose weight. The problem is that the body often fights back. Hunger can increase, cravings can become stronger, and the body may try to regain lost weight.
That is why new treatments are important. They may help reduce hunger and make weight management more achievable.
The results from Retatrutide suggest that future medicines may help some people lose weight similar to the amount seen after bariatric surgery, such as gastric bypass surgery.
This does not mean surgery will no longer be needed. Surgery is still the right treatment for some people. But it does mean that people may have more treatment choices in the future.
Were there side effects?
Yes. Like other medications, retatrutide can cause side effects.
The most common side effects were feeling sick, diarhoea, constipation and/or vomiting. These side effects were more common with higher doses.
Some people also reported unusual skin sensations, such as tingling or altered feeling. There were also slightly more urinary tract infections in people taking retatrutide compared with placebo.
Most side effects were mild or moderate, but some people did stop treatment because of side effects.
This is why medicines like this need to be prescribed carefully. The dose should be increased slowly, and people should be monitored properly.
More weight loss is not always better
The aim of obesity treatment is not simply to lose as much weight as possible. The aim is to improve health, confidence, movement, wellbeing and quality of life.
If weight is lost too quickly, or if too much weight is lost, there can be problems such as loss of muscle, tiredness, poor nutrition and gallstones
This is why good nutrition, physical activity and strength exercises are still very important during weight loss treatment
The Weight Doc view
Retatrutide could become a very important treatment for obesity in the future.
The TRIUMPH-1 results are impressive. They show weight loss that is close to the amount usually seen with bariatric surgery.
But Retatrutide is not approved yet, and we still need more information. We need to see the full published results, longer-term safety data, and how it compares with current treatments such as Mounjaro and Wegovy.
If Retatrutide does become available, it should be used as part of proper medical care. People will still need support with nutrition, movement, strength, sleep, stress, side effects and long-term weight maintenance. Obesity is a chronic condition. Our treatments, services and expectations need to reflect that.
Bottom line: Retatrutide is not available in routine clinics yet, but the early phase 3 results suggest it could become one of the most powerful medical treatments for obesity so far.