There is no official semaglutide to tirzepatide conversion chart. See how prescribers approach switching doses, plus a side-by-side dosing reference.
There is no official semaglutide to tirzepatide conversion chart. The two drugs are different molecules with different receptor targets, and no regulatory agency has published an equivalent-dose formula. In real practice, most prescribers restart tirzepatide at its lowest dose no matter how much semaglutide a patient was taking, then titrate upward based on tolerance.
That one fact matters more than any table. What follows is a practical reference for how switching is usually handled, plus the safety details that deserve more attention than the milligram numbers.
Why There Is No Official Conversion Chart
Semaglutide is a GLP-1 receptor agonist. Tirzepatide is a dual GIP and GLP-1 receptor agonist. Because tirzepatide acts on two hormone pathways instead of one, its milligram dose cannot be mapped onto semaglutide's on a one-to-one basis.
Manufacturers do not publish cross-drug equivalencies, and the FDA has not approved a conversion formula. A 1 mg semaglutide dose and a 1 mg tirzepatide dose are not the same amount of drug activity, even though the numbers look comparable.
- Semaglutide — GLP-1 agonist; weekly weight-management doses run from 0.25 mg to 2.4 mg.
- Tirzepatide — dual GIP/GLP-1 agonist; weekly weight-management doses run from 2.5 mg to 15 mg.
- Overlapping numbers — the two ranges sit in the same numeric territory, which is exactly what makes mg-for-mg substitution unsafe.
Side-by-Side Dosing Reference
A standard tirzepatide dosage chart and a semaglutide schedule look similar in structure but move in very different increments. The table below shows the typical titration steps for the brand-name weight-management products.
| Step | Semaglutide (Wegovy) | Tirzepatide (Zepbound) |
|---|---|---|
| Weeks 1–4 | 0.25 mg weekly | 2.5 mg weekly |
| Weeks 5–8 | 0.5 mg weekly | 5 mg weekly |
| Weeks 9–12 | 1 mg weekly | 7.5 mg weekly |
| Weeks 13–16 | 1.7 mg weekly | 10 mg weekly |
| Weeks 17–20 | 2.4 mg weekly (max) | 12.5 mg weekly |
| Week 21+ | 2.4 mg weekly (max) | 15 mg weekly (max) |
Semaglutide steps up by 0.25 to 0.7 mg at a time. Tirzepatide steps up by 2.5 mg at a time. Comparing those numbers directly tells you nothing about relative potency.
How Prescribers Usually Handle the Switch
If you want to know how to switch from semaglutide to tirzepatide, the short answer is that you stop one drug and start the other at the bottom of its range. Most clinicians do not try to match doses. The table below reflects common practice, but your prescriber may choose differently based on your history and side effects.
| Prior semaglutide weekly dose | Common tirzepatide restart dose | Notes |
|---|---|---|
| 0.25–0.5 mg | 2.5 mg | Standard starting point |
| 1 mg | 2.5 mg | Some clinicians start at 5 mg |
| 1.7 mg | 2.5 mg | Titrate after 4 weeks if tolerated |
| 2.4 mg | 2.5–5 mg | Higher start only with prescriber approval |
Two other details come up constantly when people change drugs:
- Washout period. Some prescribers have patients skip a week between the two drugs; others start tirzepatide on the next scheduled injection day. Both approaches are used.
- Side effects carry over. If you had significant nausea, reflux, or constipation on semaglutide, expect a similar experience during tirzepatide titration.
Compounded Versions and Reconstitution Math
Compounded GLP-1 medications come in different formats, which adds a layer of confusion. Some arrive as ready-to-use liquid. Others arrive as a lyophilized powder that must be mixed with bacteriostatic water before use.
Reconstitution math is a separate skill from dose conversion. A question like how much bac water to reconstitute 20mg tirzepatide is about concentration, not about equivalence to semaglutide. More water means a larger volume per injection, not a stronger dose.
Concentration, not conversion
If 20 mg of powder is mixed with 2 mL of water, the concentration is 10 mg/mL, so a 2.5 mg dose is 0.25 mL. Mix the same powder with 4 mL and the concentration is 5 mg/mL, so a 2.5 mg dose is 0.5 mL. Same drug, same dose, different syringe volume.
Safety, Sourcing, and Red Flags
Both drugs carry a boxed warning about thyroid C-cell tumors and are contraindicated in people with a personal or family history of medullary thyroid cancer or MEN2. Neither drug should be started without a prescriber involved, and neither is appropriate during pregnancy.
If you are weighing is it safe to buy semaglutide online, treat unverified sellers as a hard no. Counterfeit pens and misdosed vials are widely documented, and there is no reliable way to confirm what a gray-market product actually contains.
- Check that any compounding pharmacy is licensed in your state and operates under 503A or 503B standards.
- Report severe or persistent abdominal pain, which can signal pancreatitis.
- Watch for gallbladder symptoms such as right-upper abdominal pain, fever, or jaundice.
Tracking Results After the Switch
People switch for different reasons: supply shortages, insurance coverage, cost, or a plateau in results. On semaglutide vs tirzepatide weight loss, the SURMOUNT-5 head-to-head trial found greater average weight reduction with tirzepatide than with semaglutide, but individual responses vary widely.
Expect a short adjustment period. Appetite suppression may feel different during the first month on the new drug, and it usually stabilizes as the dose increases. Track your weight, side effects, and injection dates so your prescriber has real data to work with at the next visit.
No dosing table replaces an individualized plan from a licensed healthcare professional who knows your medical history.
Frequently Asked Questions
Is there an official semaglutide to tirzepatide conversion chart?
No. Neither the FDA nor the manufacturers of semaglutide and tirzepatide publish an equivalent-dose conversion. The two drugs act on different receptor pathways, so their milligram doses are not interchangeable. Most prescribers restart tirzepatide at 2.5 mg weekly regardless of the previous semaglutide dose.
What dose of tirzepatide do I start at after taking semaglutide?
The standard starting dose is 2.5 mg once weekly, even for patients who were on semaglutide 1.7 mg or 2.4 mg. After four weeks, the dose typically increases to 5 mg if it is well tolerated. Some clinicians start higher, but only with a clear clinical reason and close follow-up.
Can I switch from semaglutide to tirzepatide without a washout period?
Many prescribers allow the switch on the next scheduled injection day with no gap, while others recommend skipping one week. Either approach is used in practice. Because both drugs slow gastric emptying and share gastrointestinal side effects, the decision should come from your prescriber rather than a chart.
This page provides educational research information and does not replace medical advice, diagnosis, or treatment.