What it is
Semaglutide is a peptide made of 31 amino acids. It is made in a lab by the drug company Novo Nordisk. It copies GLP-1, a hormone the gut releases after eating. GLP-1 tells the pancreas to release insulin when blood sugar is high, slows how fast the stomach empties, and lowers hunger. Natural GLP-1 lasts about 2 minutes in the blood. Semaglutide has one amino acid swapped and a fatty acid chain attached. The chain sticks to albumin, a protein in the blood, which keeps semaglutide in the body for about a week. The FDA approved it as Ozempic for type 2 diabetes, Wegovy for weight management, and Rybelsus, a daily pill for type 2 diabetes. Other names: Ozempic, Wegovy, Rybelsus.
What researchers study it for
- Blood sugar in type 2 diabetes
- Body weight in people with obesity
- Heart attack, stroke, and heart death
- Fatty liver disease with inflammation, called NASH
- The pill form
What the studies found
1. Adults with obesity lost about 15 percent of body weight in 68 weeks.
The STEP 1 trial gave 1,961 adults with obesity or overweight a weekly shot of semaglutide or placebo. After 68 weeks, the semaglutide group lost 14.9 percent of body weight on average. The placebo group lost 2.4 percent. The most common side effects were nausea, diarrhea, and vomiting. This trial led to the approval of Wegovy.
2. People with type 2 diabetes had fewer heart attacks, strokes, and heart deaths.
The SUSTAIN-6 trial followed 3,297 people with type 2 diabetes and high heart risk for about 2 years. The combined rate of heart death, heart attack, and stroke was 26 percent lower with semaglutide than placebo. Stroke showed the biggest drop. Human data.
3. Heart events dropped 20 percent in people with obesity who did not have diabetes.
The SELECT trial enrolled 17,604 adults age 45 and older who had heart disease and overweight or obesity, but not diabetes. Over about 40 months, 6.5 percent of the semaglutide group had a heart death, heart attack, or stroke, compared to 8.0 percent on placebo. More people stopped semaglutide because of side effects, 16.6 percent compared to 8.2 percent, mostly from stomach problems. This was the first trial to show this result in people without diabetes.
4. The pill form did not raise heart risk.
The PIONEER-6 trial gave 3,183 people with type 2 diabetes and high heart risk the daily pill or a placebo. Heart events happened in 3.8 percent on the pill and 4.8 percent on placebo. The trial was built to rule out extra heart risk, not to prove a benefit. The result supported approval of Rybelsus.
5. Liver inflammation cleared in more patients with NASH.
This 2021 trial enrolled 320 people with NASH confirmed by liver biopsy. After 72 weeks, NASH cleared without worse scarring in 59 percent at the highest dose, compared to 17 percent on placebo. Liver scarring improved in 43 percent compared to 33 percent, but that difference was not statistically meaningful. Human data.
6. Tirzepatide led to more weight loss in a head-to-head trial.
The SURMOUNT-5 trial compared semaglutide with tirzepatide in 751 adults with obesity for 72 weeks. Weight dropped 13.7 percent with semaglutide and 20.2 percent with tirzepatide. Stomach side effects were the most common in both groups. Human data.
How much research exists
One of the most studied drugs of its kind, with many large human trials involving tens of thousands of people. It is approved in the United States and many other countries.
Facts
- Formula: C187H291N45O59
- Weight: 4113.6 g/mol
- CAS number: 910463-68-2
- Sequence: His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys(γGlu-γGlu-C18 diacid)-Glu-Phe-Ile-Ala-Trp-Leu-Val-Arg-Gly-Arg-Gly
- Time in the blood: about 7 days
- Storage: keep the dry powder in the fridge. Keep mixed solution in the fridge.
Legal status
Approved by the FDA as Ozempic and Rybelsus for type 2 diabetes and as Wegovy for weight management and heart risk reduction. Research-grade semaglutide is not the approved product and is not approved for human use.
For research use only. Not for human use. Nothing here is medical advice.