TMS side effects and safety

Is TMS safe?

For the right patient, yes. TMS has proven safety and efficacy in many clinical trials. Like any treatment it has benefits and risks, which is why every patient has a full evaluation first.

What does TMS feel like?Florida TMS Clinic · Press play to watch

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What does TMS feel like? Most of our patients do not feel anything during treatment. Some patients may feel a tapping sensation in the area where the magnetic stimulation is being delivered. Some describe it as bubble wrap around the head in this area.

Again, for most people, after a few minutes, they do not feel anything, and it just disappears into the background.

Common side effects

• Scalp discomfort at or near the coil, reported by about 5% of patients, which usually fades within a few sessions
• Headache, mostly early in the course, which usually eases as you get used to the tapping sensation. We can adjust the intensity, and an over-the-counter pain reliever before treatment may help.
• Twitching of the eyelid or jaw during stimulation

What are the side effects of TMS?Florida TMS Clinic · Press play to watch

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Are there any side effects to TMS therapy? There are no systemic side effects to TMS therapy. Unlike medications, there is no weight gain, no sexual side effects, no dry mouth, and no stomach issues. Those systemic side effects that occur with medications and antidepressants do not occur with TMS therapy.

That being said, there may be some local discomfort in the area of the head where we are delivering the magnetic pulse. Usually, this goes away after just a few minutes.

Less common effects

• Manic or hypomanic symptoms. We watch for early signs, and if they appear we pause treatment and follow up closely.
• Decreased hearing from the clicking noise. Every patient wears earplugs at every session.
• Lightheadedness or fainting, especially with anxiety, dehydration or low blood sugar
• Seizure, which is very rare. The risk is estimated at about 1 in 30,000 treatments, and newer real-world data suggest it may be lower.

Who should not have TMS?

The main absolute contraindication is a movable ferromagnetic object inside the head, such as a brain stent, clip or deep brain stimulator.

Other situations need further evaluation with the doctor before TMS: a history of seizure, head injury or brain surgery, metal in the head or neck outside the skull such as shrapnel or surgical clips, and some implanted devices such as pacemakers.

Common safety questions

• Does TMS cause memory loss? No clinical evidence shows that it does.
• Does TMS cause brain damage? No, provided screening rules out contraindications.
• Does TMS cause insomnia? Not directly, and many patients report better sleep.
• Can I have TMS with dental implants? In most cases, yes. Tell your doctor where they are.
• Can I have TMS with a pacemaker? Possibly, with extra care and coordination with your cardiologist.
• Can I have TMS with a brain stimulator? No, it is contraindicated.
• Can I have TMS with a spinal cord stimulator? Yes, if it sits in the thoracic or lumbar spine.

Talk to Dr. Bowarshi

Safety starts with a full evaluation. Call (813) 867-2378 to schedule yours in Wesley Chapel or Tampa.

Frequently asked questions

Sources and further reading

1. Perera T, et al. The Clinical TMS Society consensus review and treatment recommendations for TMS therapy for major depressive disorder. Brain Stimul. 2016;9(3):336–346. Clinical TMS Society
2. Trapp NT, et al. Consensus review and considerations on TMS to treat depression. Clin Neurophysiol. 2025;170:206–233. Clinical TMS Society / NNDC / IFCN
3. Brain Stimulation Therapies. National Institute of Mental Health