Semaglutide

What people use it for

• Type 2 diabetes (blood-sugar control)
• Chronic weight management
• Cardiovascular risk reduction in eligible patients

What Semaglutide does in the body

Mimics the gut hormone GLP-1. It increases glucose-dependent insulin release, reduces glucagon, slows stomach emptying and acts on appetite centres in the brain, which lowers hunger and food intake. A fatty-acid side chain lets it bind albumin, giving it a half-life of about a week.

Strength of evidence

Strong: multiple large randomized controlled trials (SUSTAIN, STEP, SELECT programs).

Look up the evidence

• Reviews on PubMed: Summaries of the published research
• Clinical trials on PubMed: Published studies in people
• ClinicalTrials.gov: Registered trials, past and ongoing
• Prescribing information (DailyMed, US): Official US label
• Patient leaflets (emc, UK): Official UK product information

Live searches of official databases. New to the terms? See the glossary.

Reported side effects & risks

• Nausea, vomiting, diarrhea, constipation (most common, usually during dose increases)
• Gallbladder problems and pancreatitis (uncommon)
• Boxed warning: thyroid C-cell tumors in rodents; contraindicated with a personal/family history of medullary thyroid cancer or MEN2
• Low blood sugar when combined with insulin or sulfonylureas

Who should avoid it or take extra care

• Personal or family history of medullary thyroid cancer or MEN2
• Pregnant, breastfeeding or planning pregnancy (stop well before trying to conceive; ask your doctor)
• Past pancreatitis (talk to your doctor first)
• Type 1 diabetes (it is not a substitute for insulin)

Not a complete list. Check with a doctor or pharmacist about your own health and medicines.

Regulatory status

FDA-approved as Ozempic and Rybelsus (diabetes) and Wegovy (weight management). Compounded versions are subject to changing FDA rules.

How it's taken

Route: Injection under the skin once a week (Ozempic, Wegovy), or a daily tablet (Rybelsus)

How long it lasts (half-life): About 1 week

Storage

Branded pens: refrigerate before first use. Compounded vials: follow pharmacy guidance.

Mixing guides

How much water to add and what each syringe mark holds, worked out for your own dose:

• 2 mg vial
• 5 mg vial
• 10 mg vial

Found in these stacks

• CagriSema: Novo Nordisk's experimental once-weekly combination of an amylin analogue and semaglutide for obesity.