What is Semaglutide and what it does to your body
What Is Semaglutide?
Semaglutide is a prescription only medication that belongs to a class of drugs known as glucagon-like peptide-1 (GLP-1) receptor agonists. It is used to support both blood glucose control in people with type 2 diabetes as well as medically supervised weight loss. It works by mimicking a natural hormone in the body (GLP-1), activating receptors in the pancreas, brain and gut to regulate appetite and glucose levels.
Blood sugar control and metabolic health
Semaglutide improves glucose regulation through several coordinated effects:
- Stimulates insulin release when blood sugar levels are high
- Reduces glucagon production preventing excess glucose release into the bloodstream
- Slows gastric emptying leading to a more gradual absorption of glucose after meals
- Helps maintain more stable, balanced blood sugar levels throughout the day
These combined actions make it an effective treatment for improving glycaemic control in those with type 2 diabetes.
Appetite control and weight loss
In addition to its metabolic benefits, Semaglutide plays a significant role in weight management by targeting appetite regulation:
- Acts on GLP-1 receptors in the brain, particularly in areas that regulate hunger
- Increases feelings of satiety, leading to reduced caloric intake
- The slowing of gastric emptying also contributes to prolonged feelings of fullness after meals
Semaglutide Injectables
Semaglutide is available in the UK in two commonly prescribed injectable forms: Wegovy and Ozempic. Wegovy is specifically approved for chronic weight management and is typically prescribed at a higher maintenance dose whilst Ozempic is primarily used to manage Type 2 Diabetes. Both medications are administered once weekly using a pre-filled pen designed for simple and convenient self-administration at home. The injection is given just under the skin (subcutaneously) usually in the abdomen, thigh or upper arm. Treatment generally starts at a lower dose and is gradually increased over time to minimise side effects, with Wegovy reaching a higher maintenance dose (up to 7.2 mg) compared to Ozempic (up to 2.0 mg).
Semaglutide Oral Tablets
Semaglutide is also available in the UK as an oral tablet known as Rybelsus approved for the management of type 2 diabetes. This formulation includes a special absorption enhancer that allows the medication to be taken up through the stomach lining making oral dosing possible. To ensure effectiveness it must be taken on an empty stomach with a small amount of water, followed by a 30-minute wait before eating or drinking anything else. As the body absorbs less semaglutide in tablet form compared to injectables, Rybelsus must be taken daily.
Side Effects and Safety Considerations of Semaglutide
Like all medications, semaglutide can cause side effects. The most common ones are gastrointestinal symptoms, including:
- Nausea
- Vomiting
- Diarrhoea or constipation
- Stomach discomfort
Clinical trials have found these effects are usually mild, temporary, and tend to appear during the dose-increase phase (when your body is getting used to the medication). Most people find they settle over time.
Serious but Rare Side Effects
While uncommon, there are a few more serious risks to be aware of:
- Pancreatitis (inflammation of the pancreas): This can cause severe stomach pain, vomiting, and fever. Seek urgent medical help if this happens.
- Allergic reactions: Rarely, people may experience anaphylaxis, which is a severe allergic reaction. Signs include swelling, difficulty breathing, dizziness, or a fast heartbeat. Call emergency services immediately if you notice these.
- Thyroid concerns: Animal studies found a potential link to a rare type of thyroid cancer called medullary thyroid carcinoma (MTC). Because of this, Semaglutide isn’t suitable for anyone with a personal or family history of MTC or a condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN2).
Prescribers continue to monitor the long-term safety of semaglutide, but current research suggests that serious side effects are uncommon and that the benefits outweigh the risks for most people.
If you’re considering semaglutide (Wegovy) for your weight loss journey, our expert clinical prescribers here at Phlo Clinic can guide you safely, monitor your progress and support you along the way!
References
Wegovy 0.25 mg, FlexTouch solution for injection in pre-filled pen. Summary of Product Characteristics (SmPC) - (emc)
Ozempic 0.25 mg, Solution for injection in pre-filled pen. Summary of Product Characteristics (SmPC) - (emc)
Rybelsus 1.5 mg, Tablet. Summary of Product Characteristics (SmPC) - (emc)
Wilding, J.P.H. et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. 2021;384(11):989–1002.
