Zepbound (tirzepatide) starts at 2.5 mg a week and can go up to 15 mg. The Wegovy (semaglutide) pen starts at 0.25 mg a week and reaches 2.4 mg by week 17, with 7.2 mg (Wegovy HD) as an option. The Wegovy pill (oral semaglutide) starts at 1.5 mg a day and reaches 25 mg by day 91. Foundayo (orforglipron) starts at 0.8 mg a day and can go up to 17.2 mg. Each FDA label steps the dose up slowly to keep stomach side effects manageable.
Four medicines, two forms (shots and pills), and a different dose ladder for each. If you're deciding between them, or you just want the whole picture on one sheet, here it is, straight from the FDA labels.
Every GLP-1 at a glance
| Medicine | How you take it | Starts at | Steps | Maintenance | Maximum |
|---|---|---|---|---|---|
| Zepbound (tirzepatide) | Injection, once a week | 2.5 mg for 4 weeks | Up 2.5 mg at a time, at least 4 weeks apart | 5, 10 or 15 mg | 15 mg |
| Wegovy (semaglutide) | Injection, once a week | 0.25 mg for 4 weeks | 0.5, 1, 1.7 mg, each for 4 weeks | 2.4 mg (or 1.7 mg) | 7.2 mg (Wegovy HD), after at least 4 weeks on 2.4 mg |
| Wegovy pill (oral semaglutide) | Tablet, every morning, empty stomach | 1.5 mg for 30 days | 4 mg, then 9 mg, each for 30 days | 25 mg | 25 mg |
| Foundayo (orforglipron) | Tablet, once a day, any time | 0.8 mg for at least 30 days | 2.5 mg, 5.5 mg, then 9, 14.5 or 17.2 mg, at least 30 days apart | Not one set dose. After 5.5 mg, steps depend on how you respond | 17.2 mg |
Before you take any of them
- Don't take any of them if you or anyone in your family has had medullary thyroid cancer, or if you have multiple endocrine neoplasia syndrome type 2 (MEN 2).
- Tell your healthcare provider about a lump or swelling in your neck, hoarseness, trouble swallowing or shortness of breath.
- If you also take insulin or a sulfonylurea, ask whether those doses need lowering, because low blood sugar is more likely.
- Tell your prescriber if you're pregnant or planning to be. Each label says to stop when a pregnancy is confirmed, and Wegovy's says to stop at least 2 months before a planned pregnancy.
- Breastfeeding isn't recommended with the Wegovy pill or Foundayo.
From the Zepbound, Wegovy and Foundayo prescribing information (boxed warnings, sections 4, 5 and 8).
Each dose ladder
Zepbound (weekly)
| Weeks 1 to 4 | 2.5 mg |
| From week 5 | 5 mg |
| Week 9 at the earliest | 7.5 mg |
| Week 13 at the earliest | 10 mg |
| Week 17 at the earliest | 12.5 mg |
| Week 21 at the earliest | 15 mg |
2.5 mg is a starting dose only. Maintenance for weight loss is 5, 10 or 15 mg; for sleep apnea, 10 or 15 mg.
Wegovy pen (weekly)
| Weeks 1 to 4 | 0.25 mg |
| Weeks 5 to 8 | 0.5 mg |
| Weeks 9 to 12 | 1 mg |
| Weeks 13 to 16 | 1.7 mg |
| Week 17 onward | 2.4 mg (or 1.7 mg) |
| After 4+ weeks on 2.4 mg, if needed | 7.2 mg (Wegovy HD) |
If a step is hard to tolerate, the label lets your prescriber wait 4 more weeks before the next one.
Wegovy pill (daily)
| Days 1 to 30 | 1.5 mg |
| Days 31 to 60 | 4 mg |
| Days 61 to 90 | 9 mg |
| Day 91 onward | 25 mg |
Take it when you wake up, with up to 4 oz of plain water, then wait at least 30 minutes before food, drinks or other pills.
Foundayo (daily)
| At least 30 days | 0.8 mg |
| At least 30 days | 2.5 mg |
| At least 30 days | 5.5 mg |
| If stepped up, at least 30 days | 9 mg |
| If stepped up, at least 30 days | 14.5 mg |
| Maximum | 17.2 mg |
Any time of day, with or without food. Some other medicines change it: with a strong CYP3A4 inhibitor (such as some antifungals and antibiotics) the label caps it at 9 mg, and it should be avoided with ritonavir and with strong CYP3A4 inducers such as carbamazepine.
Saxenda and generic liraglutide, a daily injection, are also approved for weight loss in the US. They aren't on this chart.
Why the numbers don't compare across medicines
It's tempting to read the milligrams side by side. Don't. Zepbound is tirzepatide, Wegovy is semaglutide and Foundayo is orforglipron, three different molecules. Even with the same molecule, the form matters. Only about 1% to 2% of the semaglutide in a Wegovy tablet reaches your blood, which is why the pill goes up to 25 mg while the pen stops at 2.4 mg (or 7.2 mg).
The same goes for switching. There's no official conversion between these medicines, so if you change from one to another, your prescriber picks your starting dose on the new one.
For how the medicines differ beyond the dose (what each one is, how it's taken and each label's trial result), see the GLP-1 comparison chart.
Frequently asked questions
Which GLP-1 has the lowest starting dose?
Why does every GLP-1 start low and step up?
Can you compare doses between Zepbound and Wegovy?
Is a higher dose always better?
What is the highest dose of each GLP-1?
General information from the FDA labels, not medical advice. Your prescriber sets your doses and may move you up more slowly than these charts.
