Tirzepatide and semaglutide are type 2 diabetes drugs often used for weight management. While tirzepatide may potentially be more effective, it’s too early to know that based on current research.

Using medications for weight loss is becoming more common. Doctors sometimes prescribe newer type 2 diabetes drugs to help with weight management. This use is “off-label,” meaning that doctors give the drug for a different condition than what its Food and Drug Administration (FDA) approval is for.

Two drugs that doctors prescribe for weight loss are tirzepatide and semaglutide. Both drugs can help the brain feel less hungry, but each has differences to consider with a doctor’s guidance. Research on these medications is still unclear as to which might be better.

Semaglutide is FDA approved to treat type 2 diabetes under the brand names Ozempic, Wegovy, and Rybelsus. However, only Wegovy has approval for use in managing weight.

Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist, which means it mimics the GLP-1 hormone and makes you feel less hungry.

When you eat, your digestive tract releases the GLP-1 hormone, prompting the body to create more insulin. It can also send fullness signals to the brain.

Tirzepatide is sold under the brand name Mounjaro. It’s both a glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptor agonist. Tirzepatide mimics the GLP-1 hormone and the GIP hormone. The GIP hormone can also trigger insulin creation and sensations of fullness.

This means tirzepatide may offer an extra weight loss boost. However, it’s only approved for type 2 diabetes, so any use in weight loss is off-label.

One benefit of semaglutide, though, is that it is available in both oral tablets and injections. Tirzepatide is only available as an injection.

Some recent studies have compared semaglutide and tirzepatide for weight loss.

A 2023 study found that tirzepatide resulted in greater weight loss than semaglutide. Although it costs more, researchers concluded that tirzepatide is more effective and a better value. A 2021 study also found that tirzepatide was more effective.

There are some important caveats to note about these studies, though:

  • First, the doses of semaglutide and tirzepatide given to participants were not equal. The dose of tirzepatide was higher, which may have affected the results. It’s possible that had the dose of semaglutide been at a comparable level, weight loss would have increased.
  • Additionally, these studies only looked at the weight loss effects in people with type 2 diabetes, so it’s possible those without diabetes might not have seen the same effects. Tirzepatide is currently only FDA-approved for people with type 2 diabetes. However, studies suggest semaglutide may be an effective weight loss treatment for people without diabetes.

The side effects of tirzepatide and semaglutide are similar, likely because they work in a similar manner.

Moderate side effects of tirzepatide and semaglutide can include:

  • constipation or diarrhea
  • upset stomach, nausea, and vomiting
  • headaches
  • abdominal pain
  • fatigue
  • low blood sugar (hypoglycemia)

More severe side effects of tirzepatide and semaglutide may include:

Both these medications have boxed warnings for the risk of thyroid C-cell tumors. A boxed warning is the most serious warning from the FDA.

Tirzepatide warning

There are still questions about the side effects of tirzepatide in people without type 2 diabetes. There may be more limitations and side effects that are still unknown based on current research and how new these types of medications are for use in weight loss.

Your doctor and healthcare team can provide the best guidance for you on these medications and any symptoms you may be experiencing when using Mounjaro in particular.

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Tirzepatide and semaglutide are type 2 diabetes drugs that doctors often prescribe for weight management. While tirzepatide may potentially be more effective because of how it works, current research is incomplete. It’s too early to know for sure which drug is more effective — especially for people without diabetes.

Several studies show that tirzepatide is more effective in helping individuals with type 2 diabetes lose weight. The research isn’t clear, though. Your doctor can offer the best guidance on different weight loss options and what medications may be best for you.