Semaglutide, marketed under the brand name Ozempic, is a relatively new medication that has shown promise as a treatment for obesity. Originally developed as a treatment for type 2 diabetes, semaglutide has been found to have significant effects on body weight, leading to its approval by the US Food and Drug Administration (FDA) in 2021 for use in adults with a body mass index (BMI) of 30 or higher.
In this blog post, we will explore the mechanism of action of semaglutide, its effectiveness in promoting weight loss, its safety profile, and its potential role in the management of obesity.
Mechanism of Action
Semaglutide belongs to a class of medications called glucagon-like peptide-1 (GLP-1) receptor agonists. These medications mimic the action of GLP-1, a hormone that is normally released by the intestines in response to food intake. GLP-1 stimulates the release of insulin from the pancreas, which helps to lower blood sugar levels. It also slows down gastric emptying, which helps to reduce appetite and promote feelings of fullness.
In addition to its effects on blood sugar control, GLP-1 has been found to have significant effects on body weight. Studies have shown that GLP-1 receptor agonists can lead to a reduction in body weight by increasing satiety (feelings of fullness) and reducing hunger. This effect is thought to be mediated by the central nervous system, where GLP-1 receptors are located.
Semaglutide is a long-acting GLP-1 receptor agonist that is administered once a week by subcutaneous injection. It has been shown to be highly effective in promoting weight loss in clinical trials, as we will discuss in the next section.
Effectiveness
The effectiveness of semaglutide for weight loss was demonstrated in a series of clinical trials known as the STEP trials. These trials involved over 4,500 participants who were overweight or obese and had at least one weight-related comorbidity, such as type 2 diabetes, hypertension, or dyslipidemia.
In the STEP trials, participants were randomized to receive either semaglutide or a placebo injection once a week for a period of 68 weeks. The primary endpoint of the trials was the percentage of participants who achieved a weight loss of at least 5% of their baseline body weight.
The results of the STEP trials were highly impressive. Participants who received semaglutide achieved a mean weight loss of 15-20% of their baseline body weight, compared to just 2-5% for those who received placebo. The percentage of participants who achieved a weight loss of at least 5% was 86-96% for those who received semaglutide, compared to just 31-38% for those who received placebo.
The effectiveness of semaglutide for weight loss appears to be durable, with participants in the STEP trials maintaining their weight loss even after the medication was discontinued. This suggests that semaglutide may be a useful long-term treatment option for obesity.
Safety Profile
Like any medication, semaglutide has the potential to cause side effects. The most common side effects reported in the STEP trials were gastrointestinal in nature, such as nausea, vomiting, and diarrhea. However, these side effects were generally mild and resolved on their own over time. In addition, participants who received semaglutide had a slightly higher incidence of pancreatitis and gallbladder disease compared to those who received placebo, although the absolute risk of these events was low.
