New Weight Loss Drug Shows Promising Results In Clinical Trial

Losing weight can be challenging as the body tries to prevent permanent weight loss ( 1 ). Yet, obese and overweight people must shed excess body weight to prevent the health risks associated with their conditions. According to a recent clinical trial, a newly approved type 2 diabetes drug, tirzepatide, may be a game-changer for effective weight loss methods ( 2 ).

The SURMOUNT-1 clinical trial

A clinical trial, called SORMOUNT-1, was carried out to evaluate the potential of the novel anti-diabetic drug, tirzepatide, as a new weight loss drug ( 2 ). The study was sponsored by Eli Lilly and Company, the drug maker, after tirzepatide showed promising weight loss capabilities in an earlier clinical trial carried out by the company to evaluate the blood sugar-lowering effects of the drug.

Overview of the clinical trial

A total of 2,539 obese adults were enrolled in the study. The average weight and body mass index (BMI) of the participants were 231 pounds and 38, respectively. A BMI of 30 or higher is considered obese, a criterion most (95%) of the participants met. The remaining 5% were overweight with one comorbidity excluding diabetes.

The participants were randomly divided into four groups. A group received a placebo, while the remaining three were given three different doses (5 mg, 10 mg, and 15 mg) of tirzepatide. The drugs were provided as injections once weekly.

Results of the trial

At the end of the trial, the participants on the highest dose of tirzeparide, 15 mg, lost 20.9% of their body weight which is about 52 pounds. Those on the 10 mg of the drug experienced an average weight loss of 19.5 %, which is about 49 pounds, while those that received 5mg of the drug lost about 35 pounds, which is about 15% of their body weight.

All participants kept the weight off for the entire duration of the study. Also, most of the participants’ cholesterol levels, blood pressure, and blood sugar improved at the end of the study.

Common side effects reported

The most common side effects were gastrointestinal-related effects such as nausea, diarrhea, and constipation. However, these side effects were generally mild to moderate, and only a small percentage of participants (4.3% for 5 mg, 7.1% for 10 mg, 6.2% for 15 mg, and 2.5% for placebo) were withdrawn due to the side effects.

What does the study mean for obese and overweight people?

All participants treated with tirzepatide lost at least a modest amount of weight, and the drug appears to be well-tolerated in most participants. To put the weight loss effectiveness of tirzepatide into perspective, most weight loss medications bring about an average of between 10 to 15% weight loss. For example, phentermine, the most popular prescription weight loss medication, is known to reduce weight by 5 to 10% ( 3 ). Tirzepatide, by comparison, is more effective at weight loss.

Since research shows that most people tend to regain weight loss gradually over time, weight loss methods must be ongoing ( 3 ). Therefore, Tirzepatide may be an effective and convenient way for obese and overweight people, especially those with diabetes and other comorbidities, to successfully lose weight in the long term.

More research still has to be done on the drug, and only time will tell if it’ll be approved for weight loss or not. But there’s a lot to be excited about and look forward to regarding the weight loss capabilities of the novel drug.

There is the question of the price if approval is granted

While Eli Lilly is yet to announce when it will seek FDA approval for tizepatide as a weight loss medication, the price may determine how many people use the drug if it gains FDA approval. New weight loss drugs like liraglutide (Saxenda) cost more than $1300 a month ( 4 ). And it’s unlikely tirzepatide will come cheap.

Becoming more familiar with tirzepatide

Tirzepatide is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (GLP-1) receptor agonist. It is the first drug in this class (GLP-1 agonists) to be approved by the Food and Drug Administration (FDA) for the treatment of type 2 diabetes ( 5 ). Type 2 diabetes occurs when the body cannot produce enough insulin or respond to insulin as it should.

GIP and GLP-1 are hormones released in the intestines after a meal and promote insulin release. GLP-1 may also make you feel full and satisfied, thereby reducing appetite and, consequently, the amount of food you take ( 6 ). These are the mechanisms by which they reduce blood sugar levels and act as anti-diabetic. Taken as once-daily injections under the skin, clinical trials have demonstrated the potent anti-diabetic properties of the drug ( 5 ).

  1. University of Utah Health. Why is it so hard to lose weight?
  2. Lily Investors. (2022) Lilly’s tirzepatide delivered up to 22.5% weight loss in adults with obesity or overweight in SURMOUNT-1
  3. Kim KK, Cho HJ, Kang HC, Youn BB, Lee KR. Effects on weight reduction and safety of short-term phentermine administration in Korean obese people. Yonsei Med J. 2006 Oct 31;47(5):614-25. doi: 10.3349/ymj.2006.47.5.614. PMID: 17066505; PMCID: PMC2687747.
  4. GoodRx. Saxenda
  5. Lily Investors. (2022) FDA approves Lilly’s Mounjaro™ (tirzepatide) injection, the first and only GIP and GLP-1 receptor agonist for the treatment of adults with type 2 diabetes.
  6. Seino Y, Fukushima M, Yabe D. GIP and GLP-1, the two incretin hormones: Similarities and differences. J Diabetes Investig. 2010 Apr 22;1(1-2):8-23. doi: 10.1111/j.2040-1124.2010.00022.x. PMID: 24843404; PMCID: PMC4020673.