Semaglutide is medication meant to regulate blood sugar levels for patients with type 2 diabetes, and is often used after other medications fail to control blood sugar levels. Semaglutide is a glucagon-like peptide-1 receptor agonist. This means that it replicates the structure and function of glucagon-like peptide 1, binding to the GLP-1 receptor and stimulates insulin secretion after oral glucose consumption through the incretin effect.
Normally, when a meal is consumed, GLP-1 and glucose-dependent insulinotropic polypeptides are secreted from the intestines to the bloodstream, where they then travel to the pancreas and bind to beta cells which produce insulin. For patients with type 2 diabetes, this process can be blunted or even absent, but through the use of a GLP-1 RA like semaglutide, patients can revive their body’s insulin excretion ability – with great effectiveness.
A clinical study showed how type 2 diabetics already taking two other antidiabetic drugs that intensified this with a GLP-1 RA were “more likely to reach their blood sugar goals and lose weight compared to adding a further oral antidiabetic drug(s) or insulin.
This mention of weight loss is important to note, as this is what semaglutide is most known for. As obese people are 80 times more likely to develop type 2 diabetes, weight loss is often a necessary part of diabetic treatment and management. How one drug can have such a profound effect on patients experiencing both obesity and type 2 diabetes is rather interesting, but is better explained by examining where GLP-1 receptors are found within the brain.
GLP-1 receptors are found on the lateral hypothalamic neurons, a region of the brain associated with controlling feeding, blood pressure, heart rate, water intake and sodium excretion. Additionally, the lateral hypothalamus is a key reward-control locus in the brain, and studies have found that selective activation of GLP1 receptors in the lateral hypothalamus resulted in a decrease in food motivation, food intake, and body weight.
Additionally, a pharmacological blockade of GLP-1 receptors within the lateral hypothalamus resulted in an increase in food motivation in male rats, but not female rats. To put into perspective just how effective semaglutide can be for weight loss, a study published in June 2023 found that participants lost around 5% of their body weight (approximately 10 pounds on average) in 30 weeks. The subjects also experienced a reduction of waist size of about 1.6 inches in that same time period. This rapid rate of weight loss is further validated by a 2022 review of semaglutide stating that participants lost, on average, 14.9%-17.4% of their body weight after 68 weeks.
The impressive success rates of weight loss with semaglutide is backed by reviews like the 2022 study that have not only showcased the effectiveness but also raised intriguing questions about its surging off-label popularity.
