Switching From Semaglutide to Tirzepatide: Dose, Timing, First Month

Why it isn’t a one-to-one switch

Certainly people can and do move from one to the other all the time. We want them to do that if they need to. But the doses are totally different, and you may need some help.^[1]

There’s not a perfectly established swap every time. To some degree, it’s more of a clinical judgment.

How I pick the starting dose

What I typically do: if you’ve been on semaglutide for a very short time, you’re on a low dose, then we typically start out at the bottom for tirzepatide and titrate up from there, essentially like you’re starting fresh.^[1]

If you’ve been on a more moderate dose for a while, really anywhere in the middle, say one milligram, if you’re doing well, you’re tolerating it, then we might start tirzepatide at a more moderate dose, like five milligrams. That’s fairly consistent across studies.

If you are on a maximum dose or a higher dose of semaglutide, then we could potentially start even a little higher than that, depending on: are you switching because you’re not tolerating it well, or are you switching because you plateaued, and you’re hoping there may be some benefit with an alternative medicine?

So it changes a little bit depending on the circumstances, but we certainly can help people switch.

These are Dr. Snipes’s examples, not a conversion chart. Your provider sets your starting dose and every change after it.

Timing: don’t overlap

The timing is one thing that people ask about a lot, and I think we overthink it. It really doesn’t need to be as complicated. You don’t want to overlap. You’re not trying to buffer and blend the two.^[1]

If you’re doing one weekly and you’re going to go to the next one weekly, whenever that next dose is due, you’re going to jump on to tirzepatide. If you’ve been doing both twice weekly, same principle. You’re basically just going to stop. You’re not going to double up. You’re not going to overlap injections or anything like that.

From Wegovy or Zepbound to a compounded version

When people move from a brand name, like Wegovy or Zepbound, to a compounded version, there’s potential for some confusion or some mistakes there. The numbers may be different.^[2] Compounded medications are made by a pharmacy for you specifically. They do at times contain other ingredients, like glycine, for example.

So you want to go by the instructions that are specifically printed on your box, which is going to come to you. It likely will not be the same as whatever you had been doing with the pen. So don’t assume that you’re just going to continue to do the same thing. That’s how mistakes can happen. Always go by the label and the dose that’s on your prescription.

See tirzepatide with glycine dosage and compounded tirzepatide vs Mounjaro vs Zepbound.

What to expect in the first month

What to expect when people switch: the same things you can expect if there’s a possible dose increase. The same side effects you may have experienced earlier, some stomach side effects, nausea, possibly some constipation, general GI distress. All those things can come back temporarily, the same way they can every time there’s a dose change.^[3] They usually are self-limited and resolve fairly quickly, but it is something that people see quite a bit.

Another thing that people can see when you’re switching, since we do often back up slightly on the dose, is that people can have a little bit of a weight loss plateau while you then start to retitrate back up on a new agent. Don’t be alarmed if that happens. It’s kind of expected. It’s part of the process.

For the stomach side effects, see GLP-1 nausea and how to stop it.

How to get compounded tirzepatide

Compounded tirzepatide needs a prescription. At Rx Peps Direct, a licensed provider reviews your history for a $39 medical review per order, covering up to three peptides, and sets your starting dose. If approved, a licensed U.S. 503A pharmacy prepares it and bills the medication at wholesale, in 28 states plus Washington, DC. Tirzepatide is a 30-day supply at most. See Tirzepatide/B12 and Tirzepatide/B6 + Glycine.

This article is educational and is not medical advice. Compounded tirzepatide and semaglutide are not FDA approved.

Sources

1. ZEPBOUND (tirzepatide) injection, prescribing information. Eli Lilly and Company. Revised 12/2024. www.accessdata.fda.gov/drugsatfda_docs/label/2024/217806s013lbl.pdf
2. Lambson JE, Flegal SC, Johnson AR. Administration errors of compounded semaglutide reported to a poison control center: case series. J Am Pharm Assoc. 2023;63(5):1643-1645. doi.org/10.1016/j.japh.2023.06.017
3. Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med. 2022;387(3):205-216. doi.org/10.1056/NEJMoa2206038