The short answer
Tirzepatide is a once-weekly injectable that activates both GIP and GLP-1 receptors. It is the active ingredient in Mounjaro, approved for type 2 diabetes and for cardiovascular risk reduction in adults with type 2 diabetes at high risk, and Zepbound, approved for chronic weight management and for moderate-to-severe obstructive sleep apnea in adults with obesity. It carries a boxed warning about thyroid C-cell tumors and can reduce the effectiveness of oral contraceptives.
Boxed warning and contraceptive interaction
Tirzepatide caused thyroid C-cell tumors in rats; human relevance is unknown. It is contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2.
Because it slows stomach emptying, it can reduce absorption of oral hormonal contraceptives. The label advises switching to a non-oral method or adding a barrier method for four weeks after starting and after each dose increase. Other warnings include pancreatitis, gallbladder disease, low blood sugar with insulin or sulfonylureas, kidney injury from dehydration, and aspiration risk during anesthesia.
Current label check
The medication-specific claims on this page were checked against these current product labels on 2026-10-03.
| Product label | Label date | Boxed warning on that label |
|---|---|---|
| Zepbound (tirzepatide) | 2026-08-28 | Thyroid C-cell tumors |
| Mounjaro (tirzepatide) | 2026-08-27 | Thyroid C-cell tumors |
Established evidence
Products that contain tirzepatide
| Product | Approved for |
|---|---|
| Mounjaro | Type 2 diabetes glycemic control (adults and children 10 and older); cardiovascular risk reduction in adults with type 2 diabetes at high risk |
| Zepbound | Chronic weight management; moderate-to-severe obstructive sleep apnea in adults with obesity |
Established evidence
How tirzepatide works
Tirzepatide is a single peptide that activates GIP and GLP-1 receptors. Both hormones enhance insulin release after meals; GLP-1 also slows gastric emptying and reduces appetite. How much GIP contributes to weight loss is still being studied.
Established evidence
What the evidence shows
In SURMOUNT-1, adults with obesity or overweight without diabetes lost an average of about 15 to 21 percent of body weight at 72 weeks across doses, versus about 3 percent with placebo. In SURMOUNT-5, tirzepatide produced greater average weight loss than semaglutide 2.4 mg. SURMOUNT-OSA showed reductions in apnea-hypopnea index. Cardiovascular outcome data are newer than for semaglutide.
Tirzepatide in midlife
SURMOUNT-1 included many midlife women, and post hoc analyses have examined results by menopausal status and hormone therapy use. These analyses are hypothesis-generating; tirzepatide is not a menopause treatment. Muscle preservation through protein and strength training remains important.
Established evidence
Common side effects
- Nausea, diarrhea, vomiting, constipation
- Decreased appetite and indigestion
- Abdominal pain
- Injection-site reactions
- Hair loss reported during rapid weight loss
Compounded tirzepatide
The FDA declared the tirzepatide shortage resolved, which limits legal compounding. Compounded medications are not FDA approved and are not reviewed for safety, effectiveness, or quality.
Questions to ask a healthcare professional
- Zepbound, Mounjaro, or a semaglutide product for me?
- How should I adjust contraception?
- Could Zepbound address my sleep apnea?
Questions, answered
What people ask about Zepbound, Mounjaro
Is tirzepatide the same as semaglutide?+
No. Semaglutide activates only GLP-1 receptors; tirzepatide activates GIP and GLP-1 receptors.
Are Zepbound and Mounjaro the same?+
They share an ingredient but are distinct products with different FDA indications.
Does tirzepatide affect birth control pills?+
Yes, it can reduce their effectiveness. The label advises a non-oral or added barrier method for four weeks after starting and after each dose increase.
Is compounded tirzepatide FDA approved?+
No. Compounded medications are not FDA approved or FDA reviewed for safety, effectiveness, or quality.
Kindr Health does not claim to offer Zepbound, Mounjaro on this page. Availability and prescribing are not implied.
A broader care pathway
Explore metabolic health care
Learn how Kindr Health care pathways work. Any treatment decision is made by a licensed professional; a prescription is never guaranteed.
SOURCES & REFERENCES
Every clinical claim on this page is sourced.
- Zepbound prescribing information (current label) (2026) — DailyMed, U.S. National Library of Medicine. dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=Zepbound
- Mounjaro prescribing information (current label) (2026) — DailyMed, U.S. National Library of Medicine. dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=Mounjaro
- Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1) (2022) — New England Journal of Medicine. pubmed.ncbi.nlm.nih.gov/35658024
- Tirzepatide as compared with semaglutide for the treatment of obesity (SURMOUNT-5) (2025) — New England Journal of Medicine. pubmed.ncbi.nlm.nih.gov/40353578
- FDA approves first medication for obstructive sleep apnea (2024) — U.S. Food and Drug Administration. www.fda.gov/news-events/press-announcements/fda-approves-first-medication-obstructive-sleep-apnea
This resource is educational and does not replace individualized medical advice. Do not start, stop, or change a prescription without guidance from a licensed healthcare professional.