You may have started taking semaglutide and experienced a headache. This isn’t in your head (no pun intended)! Yes, headaches can be a side effect of semaglutide; however, they are typically mild, transient, and much less frequent than gastrointestinal side effects.

Does Semaglutide Cause Headaches? The Short Answer

Quick Answer: Yes. Semaglutide can cause headaches in some patients.

So, yes, semaglutide headaches are a real thing, but for most people, the headaches are mild to moderate, generally subside with time, and headaches are not a reason for discontinuing the drug. The most common side effects of semaglutide are nausea, vomiting, and diarrhea.

How Common are Headaches with Semaglutide?

We have a pretty clear idea of what to anticipate from large clinical trials.

In the STEP studies, two major studies on semaglutide for weight loss, headaches occurred a bit more frequently in the semaglutide group than the placebo group. In the STEP 1 study, headaches occurred in 15% of semaglutide participants vs. 12% of the placebo group. So, yes, more frequent, but not dramatically more common.

In meta-analysis of several trials, headaches occurred in roughly 8% of semaglutide patients taken together. More recent studies of 25 mg oral semaglutide found the same: headaches in about 12% of subjects compared to 9% of controls.

How Severe are Semaglutide Headaches?

The good news: Headaches from semaglutide are usually mild to moderate.

These are typically:

• Short lived

• Most commonly observed at the initiation of or following an increase in dosage

• Easily controlled by self-care (e.g., fluids and rest)

Specifically, headaches are not a common reason for stopping semaglutide. People tend to stop the medication due to gastrointestinal side effects, such as nausea.

Why Does Semaglutide Cause Headaches?

Headaches caused by semaglutide are a nervous system (rather than gastrointestinal) side effect. The precise mechanism is not yet fully understood, but may relate to:

• Blood sugar swings

• Initial lower calorie consumption

• Dehydration, particularly if nausea limits the consumption of fluids

Many people find that headaches ease after their bodies acclimate to the medication.

When to Worry About Semaglutide Headaches

Occasional headaches from semaglutide aren’t anything to be concerned about, but certain symptoms do warrant a conversation with your healthcare provider. If you notice any of the following, you should reach out to them:

• Severe headaches that don’t go away with over-the-counter pain relievers

• Headaches accompanied by fever, confusion, stiff neck, weakness, numbness, vision disturbances, or severe nausea/vomiting

• Frequent headaches that disrupt your daily activities

• Headaches that occur alongside rapid weight loss, vomiting, or dark urine

If you experience any of these, it’s important to discuss them with your healthcare provider. They can assess whether your symptoms are related to the medication or indicative of an underlying condition that needs attention.

Semaglutide Headaches: Key Takeaways

Headaches are possible when taking semaglutide. However, headaches are not a typical side effect, and any headaches you do have will be relatively mild and short-term. They shouldn’t be enough to affect your long-term use of the medication.

If you do get headaches, don’t panic and don’t suffer in silence. Reaching out to your provider can help you feel better and more assured as you progress through your regimen.

Resources

1. Wadden TA, Brown GK, Egebjerg C, et al. Psychiatric Safety of Semaglutide for Weight Management in People Without Known Major Psychopathology: Post Hoc Analysis of the STEP 1, 2, 3, and 5 Trials. JAMA Internal Medicine. 2024.

2. Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. 2021.

3. Feier CVI, Vonica RC, Faur AM, et al. Assessment of Thyroid Carcinogenic Risk and Safety Profile of GLP-1 RA Semaglutide. International Journal of Molecular Sciences. 2024.

4. Wharton S, Lingvay I, Bogdanski P, et al. Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity. New England Journal of Medicine. 2025.