Tirzepatide

What people use it for

• Type 2 diabetes
• Chronic weight management
• Obstructive sleep apnea in adults with obesity

What Tirzepatide does in the body

Activates both GIP and GLP-1 receptors. Together these boost insulin secretion when glucose is high, reduce appetite and slow gastric emptying. In trials it produced greater average weight loss than GLP-1-only agonists.

Strength of evidence

Strong: large randomized controlled trials (SURPASS, SURMOUNT 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, diarrhea, vomiting, constipation, reduced appetite
• Gallbladder disease and pancreatitis (uncommon)
• Boxed warning for thyroid C-cell tumors (same class warning as semaglutide)
• May reduce effectiveness of oral contraceptives during dose changes

Who should avoid it or take extra care

• Personal or family history of medullary thyroid cancer or MEN2
• Pregnant, breastfeeding or planning pregnancy
• Past pancreatitis (talk to your doctor first)
• Relying on the contraceptive pill alone in the first weeks and after dose increases (use a backup method)

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

Regulatory status

FDA-approved as Mounjaro (diabetes) and Zepbound (weight management, sleep apnea).

How it's taken

Route: Injection under the skin once a week

How long it lasts (half-life): About 5 days

Mixing guides

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

• 5 mg vial
• 10 mg vial
• 15 mg vial
• 30 mg vial