Semaglutide

The GLP-1 medicine that showed obesity treatment can protect the heart.

KEY EVIDENCE

STEP 1 · SELECT · OASIS 4

VIDEO LESSON

IN THE STUDIO
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ANIMATED EXPLAINER · SEMAGLUTIDE
STEP 1 OF 5
After a meal
The gut releases GLP-1, which fades within minutes.

How it's taken

• Weekly injection, with the dose increased about every 4 weeks to a maintenance dose

• Or a daily pill on an empty stomach with a small sip of water, at least 30 minutes before food, drink or other medicines

Side effects at a glance

• Nausea, vomiting, diarrhea or constipation, mostly while the dose climbs

• Reduced appetite and fatigue

Rare but serious

• Pancreatitis and gallbladder disease

• Not for anyone with a personal or family history of medullary thyroid cancer or MEN2

Monitoring

Weight, blood pressure, glucose and lipids at each step. Tell your surgical team you take it before any procedure.

Good to know

Beyond weight, semaglutide is FDA-approved to reduce cardiovascular events in people with heart disease and obesity, and for MASH with moderate to advanced liver fibrosis. Ozempic is approved to slow kidney disease in type 2 diabetes.

AT A GLANCE

Type

Medication

Brand names

Wegovy (injection and pill), Ozempic, Rybelsus

Status

FDA-approved

Reviewed by

Farhan Tahir, MD

Is this treatment right for you?

Prescription medicines and procedures need individual medical advice. Dr. Tahir’s team offers consults through Youthful Medicine.

How it works

A long-acting GLP-1 receptor agonist, taken as a weekly injection (Wegovy) or a daily 25 mg pill. It increases fullness, slows stomach emptying and boosts insulin release when glucose is high.

What the evidence shows

In STEP 1, adults without diabetes lost a mean 14.9% of body weight at 68 weeks versus 2.4% on placebo. In SELECT, people with established cardiovascular disease had 20% fewer heart attacks, strokes and cardiovascular deaths. The 25 mg pill produced a mean 16.6% loss in OASIS 4 and was approved in December 2025. Wegovy also received accelerated approval for MASH, an advanced form of fatty liver disease, in 2025.

Side effects & cautions

Nausea, vomiting, diarrhea and constipation are common, mostly while the dose climbs. Rare risks include pancreatitis and gallbladder disease. Not for anyone with a personal or family history of medullary thyroid cancer or MEN2. Most people regain weight after stopping.

PRIMARY SOURCE

Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med 2021;384:989–1002.

A GLP-1 receptor agonist docks on the GLP-1 receptor. Downstream: insulin rises when glucose is high, glucagon falls, the stomach empties more slowly and the brain registers fullness.

TYPICAL RESULT IN TRIALS

≈15% mean weight loss at 68 weeks

PHYSICIAN FIRST

Is this right for you?

Prescription treatments need a review of your history, labs and other medicines. Never start or stop one on your own.

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