A 2022 review of anti-obesity treatments found that semaglutide as well as tirzepatide (which has an overlapping mechanism of action) were more promising than previous anti-obesity drugs, although less effective than bariatric surgery. Adverse effects
Side effects include nausea, vomiting, diarrhea, abdominal pain, and constipation. In people with heart problems, it can cause damage to the retina of the eye (retinopathy). Other, less common side effects include kidney problems, allergic reactions, low blood sugar, and pancreatitis. Contraindications
Due to data from rodents studies of GLP1 mediated thyroid C-cell hyperplasia, their use is contraindicated in patients with a personal or family history of medullary thyroid carcinoma and in patients with multiple endocrine neoplasia syndrome type 2. Mechanism of action
Semaglutide is a glucagon-like peptide-1 receptor agonist. By mimicking the action of the incretin GLP-1, it increases the production of insulin, a hormone that lowers the blood sugar level. It appears to enhance growth of pancreatic beta cells, which are responsible for insulin production and release. It also inhibits the production of glucagon, which is a hormone that increases glycogenolysis (release of stored carbohydrate from the liver) and gluconeogenesis (synthesis of new glucose). It reduces food intake by lowering appetite and slowing down digestion in the stomach, helping to reduce body fat. Its half-life in the blood is about seven days (165–184 hours). Structure
Semaglutide is chemically similar to human GLP-1, with 94% similarity. The only differences are two amino-acid substitutions at positions 8 and 34, where alanine and lysine are replaced by 2-aminoisobutyric acid and arginine, respectively.
Amino-acid substitution at position 8 prevents chemical breakdown by dipeptidyl peptidase-4. In addition, the lysine at position 26 is in its derivative form (acylated with stearic diacid). Acylation with a spacer and C-18 fatty diacid chain increases the drugs binding to blood protein (albumin), which enables longer presence in the blood circulation. History
Semaglutide was developed in 2012, by a team of researchers at Novo Nordisk as a longer-acting alternative to liraglutide as a once-weekly diabetes therapy. It was given the brand name Ozempic. Clinical trials were started on 6 January 2016, and completed on 19 May 2017.Researchers at the University of Leeds and Novo Nordisk reported in 2017, that it can also be used for the treatment of obesity. It reduces hunger, food craving and body fat. A phase 3 randomized controlled trial found that once-weekly injection of 2.4 mg of the drug resulted in an average change of −14.9% body weight at 68 weeks compared to −2.4% for the placebo.The US FDA New Drug Application (NDA) was filed in December 2016, and in October 2017, the FDA Advisory Committee approved it unanimously. It can be administered by injection or orally.