Ozempic contains semaglutide; Mounjaro contains tirzepatide. Compare the ingredients in Ozempic vs Mounjaro, including inactive ingredients and dosing.
Ozempic's active ingredient is semaglutide, a GLP-1 receptor agonist, and Mounjaro's active ingredient is tirzepatide, a dual GIP and GLP-1 receptor agonist. Everything else in the two pens — buffers, salts, preservatives, and water — exists to keep the drug stable and sterile. The active molecule is what makes these two medications different, and it explains why their dosing, side effects, and average weight-loss results do not match.
Anyone researching mounjaro vs ozempic quickly notices the same pattern: two once-weekly injections built on two very different molecules.
The Active Ingredient in Ozempic Is Semaglutide
Ozempic is manufactured by Novo Nordisk, and semaglutide is its only active ingredient. Semaglutide copies a natural gut hormone called GLP-1. It slows how quickly the stomach empties, signals fullness to the brain, and prompts the pancreas to release insulin when blood sugar rises.
Ozempic is FDA-approved for type 2 diabetes and to lower cardiovascular risk in adults who have type 2 diabetes and heart disease. Ozempic is not FDA-approved for weight loss, though prescribers sometimes use it off-label for that purpose.
The Active Ingredient in Mounjaro Is Tirzepatide
Mounjaro is made by Eli Lilly, and tirzepatide is its only active ingredient. Tirzepatide imitates two hormones instead of one: GIP and GLP-1. That dual action reaches more appetite and blood sugar pathways than semaglutide alone.
Mounjaro is FDA-approved for type 2 diabetes. Zepbound contains the same tirzepatide molecule and is the version approved for chronic weight management. Because Mounjaro and Zepbound share a molecule, searches for tirzepatide vs mounjaro for weight loss mostly reflect brand confusion rather than a chemical difference.
Inactive Ingredients in Ozempic and Mounjaro
Inactive ingredients do not treat diabetes or drive weight loss, but they keep the solution stable, sterile, and safe to inject. They matter most if you have a known sensitivity to a specific compound.
- Ozempic: disodium phosphate dihydrate, propylene glycol, phenol, and water for injection, with sodium hydroxide or hydrochloric acid added to adjust pH.
- Mounjaro: sodium chloride, sodium phosphate dibasic heptahydrate, and water for injection, with hydrochloric acid or sodium hydroxide added to adjust pH.
The clearest difference is phenol, an antimicrobial preservative. Ozempic comes in a multi-dose pen used for several weekly doses, so it needs a preservative to prevent bacterial growth. Mounjaro uses single-dose pens that are discarded after one injection, so no preservative is required.
Ingredients in Ozempic vs Mounjaro: Side-by-Side
| Feature | Ozempic | Mounjaro |
|---|---|---|
| Active ingredient | Semaglutide | Tirzepatide |
| Drug class | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| Manufacturer | Novo Nordisk | Eli Lilly |
| Preservative | Phenol | None |
| Other inactive ingredients | Disodium phosphate dihydrate, propylene glycol, water for injection | Sodium chloride, sodium phosphate dibasic heptahydrate, water for injection |
| Pen type | Multi-dose pen | Single-dose pen |
| Maximum weekly dose | 2 mg | 15 mg |
| FDA-approved for weight loss | No (Wegovy is the approved semaglutide product) | No (Zepbound is the approved tirzepatide product) |
Does the Ingredient Difference Change Weight Loss Results?
Yes. The active ingredient is the biggest reason the two drugs produce different average outcomes. In a head-to-head trial of the weight-loss versions of these molecules, tirzepatide produced roughly 20% average body weight loss compared with about 14% for semaglutide over 72 weeks.
Individual results vary, and no medication guarantees a specific amount of weight loss. Average numbers from a trial describe groups of people, not one person's future.
Dosing and Cost Differences That Follow the Ingredients
Standard dosing is not the same. Ozempic is titrated to a maximum of 2 mg once weekly for type 2 diabetes, and Mounjaro can be increased to 15 mg once weekly. People searching for the maximum dose of ozempic for weight loss in ml are usually converting a weekly milligram dose into a measurable volume; a 2 mg dose from the 8 mg/3 mL pen equals 0.75 mL.
Why the Real Cost Usually Depends on Insurance
The mounjaro price in usa runs about $1,000 to $1,100 per month at list price without insurance, and Ozempic is close behind at roughly $1,000. When people weigh tirzepatide vs ozempic cost, insurance coverage, prior authorization rules, and manufacturer savings programs usually matter more than the list price.
Compounded semaglutide and compounded tirzepatide are not FDA-approved and have been linked to dosing errors. Verify any product's source with a licensed pharmacy or your prescriber.
Safety Notes Before You Compare
Both semaglutide and tirzepatide carry a boxed warning about thyroid C-cell tumors observed in rodents; researchers do not know whether that risk applies to humans. Common side effects include nausea, vomiting, diarrhea, constipation, and stomach pain, and they tend to be strongest right after a dose increase.
Both medications are prescription-only. A healthcare professional can review your medical history, current medications, and risk factors before deciding which active ingredient is a better fit for you.
Frequently Asked Questions
Is the active ingredient in Ozempic the same as in Mounjaro?
No. Ozempic contains semaglutide, a GLP-1 receptor agonist, while Mounjaro contains tirzepatide, which activates both GIP and GLP-1 receptors. They are different molecules in different drug classes, even though both are injected once a week.
What are the inactive ingredients in Ozempic and Mounjaro?
Ozempic contains disodium phosphate dihydrate, propylene glycol, phenol, and water for injection. Mounjaro contains sodium chloride, sodium phosphate dibasic heptahydrate, and water for injection. Both products also use small amounts of sodium hydroxide or hydrochloric acid to adjust pH.
Are Ozempic and Mounjaro FDA-approved for weight loss?
No. Ozempic is approved for type 2 diabetes and cardiovascular risk reduction, and Mounjaro is approved for type 2 diabetes. The same active ingredients are sold for weight loss under different brand names: Wegovy (semaglutide) and Zepbound (tirzepatide).
This page provides educational research information and does not replace medical advice, diagnosis, or treatment.