Tirzepatide

How it works

It activates the GIP and GLP-1 receptors: it lowers appetite, slows down the stomach and improves the body’s insulin response.

What it is used for

Type 2 diabetes (Mounjaro), weight management (Zepbound) and obstructive sleep apnea in people with obesity.

What the evidence says

In SURMOUNT-1, the highest dose led to about 20% weight loss in 72 weeks. In a head-to-head trial it caused more weight loss than semaglutide.

Side effects and cautions

Nausea, diarrhea, vomiting and constipation, especially when the dose goes up. Pancreatitis and gallbladder problems are possible. Not for people with a history of medullary thyroid cancer or MEN2. It can make hormonal birth control less reliable.

Half-life

About 5 days (label)

Makes sense for

• Adults with obesity or type 2 diabetes
• Obstructive sleep apnea with obesity

Does not make sense for

• Type 1 diabetes
• A history of pancreatitis
• Medullary thyroid cancer or MEN2
• People at a healthy weight

Boost the effect

• High-protein meals (about 1.2–1.6 g per kg of body weight a day): help keep muscle while you lose weight
• Strength training 2–3 times a week: protects muscle and strength
• Plenty of water and fiber: ease the usual constipation and nausea