Semaglutide and tirzepatide: how they differ

How they work

Your gut releases hormones after you eat. Two of them, GLP-1 and GIP, help signal fullness, slow how quickly the stomach empties and take part in how the body handles blood sugar.

• Semaglutide is a GLP-1 receptor agonist. It acts on one of those hormone pathways, the GLP-1 receptor.
• Tirzepatide is a dual GIP and GLP-1 receptor agonist. It acts on both pathways at once.

That single difference, one pathway or two, is the main thing that sets them apart. Everything else in this guide follows from it and from the individual patient.

Common side effects

Because both act on the digestive system, their most common side effects are similar and mostly affect the stomach and gut:

• Nausea
• Vomiting
• Diarrhea or constipation
• Feeling full quickly, bloating or stomach discomfort

These effects are often most noticeable when treatment starts or when the dose goes up, and many people find they ease with time. People do not all react the same way to either medicine. Tell your prescriber about any side effect, and seek care right away for severe or persistent symptoms.

Dosing and how they are taken

Both are usually given as an injection under the skin once a week. A prescriber typically starts at a low dose and increases it gradually over several weeks, which gives the body time to adjust and helps limit stomach side effects.

The starting dose, how fast it changes and the dose you stay on are decided by your prescriber for you. A compounded preparation is made to that prescriber’s prescription, so follow the directions on your label and the instructions from your prescriber, and do not change your dose on your own.

Choosing between them

There is no single right answer. A prescriber looks at the whole picture, including:

• Your medical history and any current conditions
• Other medicines and supplements you take
• Your goals and how you have responded to treatment before
• Personal and family history, including thyroid conditions, which prescribers review before either medicine
• Cost. PureHealth Compounding does not accept insurance; your prescriber or telehealth provider can tell you whether they can give you paperwork to submit for possible reimbursement

Your prescriber decides whether either medicine is appropriate for you and, if so, which one. That conversation is the place for questions about benefits, risks and what to expect.

Switching from one to the other

Some people move from one medicine to the other, for example because of side effects or a change in their treatment plan. A switch should only happen under your prescriber’s direction. The two are not dosed the same way, so the prescriber sets a new starting dose and schedule rather than simply swapping one for the other. Do not combine them or switch on your own.

The short version

Semaglutide acts on the GLP-1 pathway; tirzepatide acts on both the GIP and GLP-1 pathways. Both are weekly injections, both are started low and increased slowly, and both share similar digestive side effects. Which one fits, if either, is a decision for you and a licensed prescriber.

Compounded semaglutide and compounded tirzepatide are not FDA-approved, and neither is the same as an FDA-approved product. Each compounded preparation is made for one patient from a valid prescription written by a licensed prescriber, who is responsible for confirming the medication is appropriate for that patient.

Already working with a prescriber? Request a prescription and we will coordinate with their office.