GLP-1 / GIP Dual Agonist
Tirzepatide
GLP-1 / GIP dual agonist · Mounjaro · Zepbound
The active ingredient in Mounjaro and Zepbound — a dual-hormone approach to weight loss available through licensed telehealth providers.
Tirzepatide is the active ingredient in Mounjaro (FDA approved for Type 2 diabetes) and Zepbound (FDA approved for weight management). Unlike older GLP-1 drugs, tirzepatide is a dual agonist — it activates both the GLP-1 and GIP receptors simultaneously. This dual mechanism produces stronger weight loss than any previously approved medication of this type: clinical trials showed an average loss of over 20% of body weight in some groups. Compounded tirzepatide is available through telehealth providers and licensed 503B pharmacies, often at a fraction of the cost of branded versions.
What Tirzepatide is used for
Tirzepatide is FDA approved for the following indications and is widely prescribed for these uses through telehealth providers.
- Significant weight loss (20%+ in trials)
- Blood sugar control in Type 2 diabetes
- Appetite suppression and reduced cravings
- Improved metabolic markers (cholesterol, blood pressure)
- Chronic weight management
How does tirzepatide work?
Tirzepatide is a first-in-class dual GIP and GLP-1 receptor agonist. Where semaglutide activates only the GLP-1 receptor, tirzepatide activates both:
- GLP-1 receptor: Slows gastric emptying, reduces appetite, and improves insulin secretion — the same mechanism as semaglutide.
- GIP receptor: GIP (glucose-dependent insulinotropic polypeptide) is another gut hormone that regulates fat storage and energy metabolism. Activating it alongside GLP-1 appears to amplify the metabolic effects significantly.
In the SURMOUNT-1 trial (Zepbound), participants on tirzepatide 15 mg lost an average of 22.5% of body weight at 72 weeks — substantially more than the ~15% seen with semaglutide 2.4 mg. Head-to-head data is still limited, but indirect comparisons consistently favor tirzepatide for weight loss magnitude.
Tirzepatide vs. semaglutide: which is stronger?
Both are effective, but the available evidence tilts in tirzepatide's favor for weight loss:
- Average weight loss: ~15% with semaglutide 2.4 mg (STEP 1) vs. ~20–22% with tirzepatide 10–15 mg (SURMOUNT-1). These were different trials, not head-to-head.
- Blood sugar control: Both are highly effective; tirzepatide has shown somewhat stronger A1c reductions in diabetes trials.
- Cost: Compounded tirzepatide is generally similar in price to compounded semaglutide. Branded Zepbound and Mounjaro list at roughly similar prices to Wegovy and Ozempic.
- Side effects: Both share a GI side effect profile (nausea, diarrhea, vomiting). Tirzepatide is generally well-tolerated at the same rates as semaglutide.
A licensed provider can help you choose the right option based on your health history, goals, and what is most available or affordable for you. See our semaglutide guide for a comparison.
Who is tirzepatide for?
Tirzepatide is FDA approved for:
- Type 2 diabetes (Mounjaro): Adults needing improved blood sugar control, especially those who also need weight management.
- Chronic weight management (Zepbound): Adults with BMI ≥ 30, or BMI ≥ 27 with at least one weight-related condition (hypertension, dyslipidemia, Type 2 diabetes, sleep apnea, or cardiovascular disease).
Tirzepatide is not recommended in patients with a personal or family history of medullary thyroid carcinoma or MEN2, during pregnancy, or in those with a history of pancreatitis. A telehealth intake reviews all of these before any prescription is written.
Branded vs. compounded tirzepatide
Mounjaro and Zepbound are manufactured by Eli Lilly and contain pharmaceutical-grade tirzepatide. Compounded tirzepatide is prepared from the same active ingredient by licensed 503B outsourcing facilities under FDA oversight.
- Cost: Branded versions list for roughly $900–$1,100/month without insurance. Compounded tirzepatide typically runs $150–$400/month depending on dose.
- Insurance coverage: Mounjaro is covered by many plans for diabetes. Zepbound has limited coverage for weight loss. Compounded versions are almost never covered.
- Availability: Eli Lilly faced significant supply constraints at launch. Compounding became widely available as demand outpaced supply.
Use Rx.com's Mounjaro price comparison or Zepbound price comparison to find the best price near you on branded versions.
Common side effects
Side effects of tirzepatide are similar to other GLP-1 drugs and are primarily gastrointestinal:
- Nausea (most common, especially during dose increases)
- Diarrhea
- Decreased appetite
- Vomiting
- Constipation
- Stomach pain or bloating
Most GI side effects improve after the first few weeks and can be managed by eating smaller meals, avoiding high-fat foods, and staying hydrated. The dose titration schedule (starting at 2.5 mg/week and increasing every 4 weeks) is designed to minimize side effects.