Peptide drugs are used to treat a variety of health conditions. Some may even help people who are overweight and obese lose weight and manage obesity-related conditions.

A peptide is a small chain of amino acids that makes up proteins in the body. Therapeutic peptides are made to treat various health issues, including type 2 diabetes, HIV, and irritable bowel syndrome. Peptides are also a new tool doctors are prescribing to help people lose weight.

Here’s what you need to know about peptides for weight loss, which ones work best, and what side effects you may experience while using them.

Yes. While the initial purpose of peptide drugs did not revolve around weight loss, researchers noticed that people did lose weight while using them.

In particular, glucagon-like peptide-1 (GLP-1) and its receptor agonists may help people lose weight. They stimulate the release of insulin, which improves blood sugar, so they’re often used to treat type 2 diabetes.

Beyond that, they may reduce appetite and promote fullness. When people aren’t hungry and feel full, they may not eat as much. Over time, this may cause weight loss.

However, experts point out that peptides may not make everyone lose weight. More factors are at play, including diet and exercise habits, personal health history, and a person’s individual reaction to peptide drugs.

There are a number of peptide drugs that are marketed for weight loss. The following were recently identified by the Journal of Obesity & Metabolic Syndrome as the “next generation” of weight-loss medications.

Your doctor can help you find the one that works best for you and your health.


The peptide drug of the moment is semaglutide. This GLP-1 receptor agonist is labeled to treat type 2 diabetes (brand name Ozempic) or obesity (brand name Wegovy). It’s approved by the Food and Drug Administration (FDA) and typically given via a once-weekly injection.

The effects of this drug seem to work well in the first year and may plateau around week 60 of treatment.


Liraglutide (brand name Saxenda) is another GLP-1 receptor agonist that is specifically approved for weight loss. Researchers explain that it reduces appetite and helps people keep weight off for at least a year. This medication is typically given in a once-daily injection.

It’s important to note that — while both semaglutide and liraglutide are “significantly” effective weight loss tools — experts believe semaglutide is a better value for the money than liraglutide.


Tirzepatide (brand name Mounjaro) is also a GLP-1 receptor agonist used to treat type 2 diabetes. In a study on over 2,500 adults, people who took varying doses of tirzepatide (ranging from 5 mg to 15 mg) experienced a “substantial and sustained” reduction in their weight over 72 weeks compared to those who received a placebo.

This drug is approved by the FDA to treat diabetes and can be used off-label to treat obesity. It’s typically given via a once-weekly injection.

Weight loss varies by person and dosage of peptides.

In a clinical trial of Ozempic (semaglutide), participants lost 8.3% of their body weight in a year compared to just 2.2% in the control group. If a person weighs 300 lb, for example, 8.3% of their body weight figures to a loss of 25 lb.

Other reports found the following:

  • People who took Wegovy lost an average of 14.9% of their body weight compared to 2.4% in the placebo group over a 68-week period.
  • People who took liraglutide lost around 8% of their body weight compared to 2.6% in the control group over a 56-week period.
  • People who took tirzepatide experienced up to a 15% loss of body weight at the end of a 72-week study period.

Combining peptides with exercise is even more effective. In one study on liraglutide, participants who took the drug and exercised 150 minutes a week (moderate intensity) or 75 minutes a week (vigorous intensity) reduced their weight and body fat twice as much as participants who took the drug alone.

Not only that, but combining exercise with medication also improved their insulin sensitivity, cardiovascular fitness, and overall sense of well-being.

You’ll need a prescription for peptide drugs. They’re administered either daily or weekly and may be taken by injection or orally.

Currently, Wegovy (semaglutide) is approved for use in people who have a body mass index (BMI) in the obese category (a BMI of 30 or above) or people who are overweight (a BMI of 27 or above) who also have at least one weight-related health condition, including:

The other peptide drugs may have different indications for use and dosage guidelines. Speak with your doctor to see whether these drugs are the right fit for you and your health goals.

Overall, peptides do not cause serious side effects. The most common side effects with GLP-1 receptor agonists are gastrointestinal issues (nausea, constipation, and diarrhea). These effects may range from mild to moderate and mainly show up when increasing dosages.

Researchers explain that weight loss in people who experience GI issues is slightly greater than in those who do not experience this side effect.

Losing just 5% of body weight may reduce the risk of cardiovascular disease and other obesity-related health issues. If you’re having trouble nudging the scale, make an appointment with your doctor. Peptide drugs may help with weight loss and with treating obesity-related conditions like type 2 diabetes.

Your doctor can also refer you to a dietitian or other medical professional for guidance with diet and exercise, optimizing weight loss and improving your overall health.