TMS Side Effects: What Patients Actually Feel and How We Keep Treatment Comfortable

Most TMS side effects are mild and short-lived. The most common are a tapping or aching sensation on the scalp where the coil sits and a mild headache, and both usually ease within the first week or two of treatment. Serious side effects, including seizures, are rare when TMS is delivered within published safety guidelines.

If you are reading this, there is a good chance antidepressants have not given you the relief you hoped for, or their side effects became their own problem. That is often the point where patients first ask us about TMS therapy, and the first question is almost always the same: what will it feel like, and is it safe? Below, we walk through what the research shows, what we see in our Friendswood office, and how we handle each side effect if it shows up during your treatment for depression, OCD, or anxiety.

The most common TMS side effects are scalp discomfort at the treatment site, mild headache, and brief twitching of the scalp, jaw, or face muscles during stimulation. The National Institute of Mental Health also lists brief lightheadedness and dizziness. These effects tend to happen during or shortly after a session rather than lingering through your day.

A 2020 systematic review in the International Journal of Geriatric Psychiatry gives a sense of scale. Across 331 older adults treated with TMS for depression, headache was reported in 6.9% and pain at the stimulation site in 3.0%. Results in other age groups and protocols vary, so treat those numbers as a reference point, not a prediction for you.

Is TMS Safe, and How Rare Are Seizures?

Yes, for properly screened patients TMS has a strong safety record, and seizures are rare. A 2020 literature review in Neuropsychiatric Disease and Treatment reported that TMS delivered within published guidelines to people without risk factors appears to cause fewer than one seizure per 60,000 sessions. The same review notes that most of the seizures it examined happened during the first few treatments.

That pattern shapes how we work. Your first sessions are when we watch most closely, and the screening we do before treatment is designed to identify the factors that raise risk, such as a personal history of seizures, a recent head injury, heavy alcohol use, or medications that lower the seizure threshold.

TMS also differs from electroconvulsive therapy (ECT) in ways that matter for side effects. TMS does not require anesthesia, it targets a specific area of the brain rather than stimulating it broadly, and it is performed in an office setting. You stay awake and alert for the entire session, and you can drive yourself home afterward and go back to your normal routine.

How Long Do TMS Side Effects Last?

For most patients, scalp discomfort and headaches are strongest in the first week and fade as treatment continues. Each sensation is usually tied to the session itself: it starts when the pulses begin and settles soon after they stop. Most patients find that sessions become easier to tolerate as treatment continues.

A standard course runs daily sessions, five days a week, for four to six weeks, according to NIMH. At our clinic, each session for depression follows an approximately 19-minute protocol.

As part of your informed consent prior to starting TMS, we discuss potential side effects and that long-term effects remain a research priority, and systematic long-term follow-up studies remain limited.

TMS is not recommended for people with certain metal or electronic implants in or near the head. Federal FDA guidance for TMS devices lists contraindications including cochlear implants, aneurysm clips or coils, stents, deep brain stimulators, vagus nerve stimulators, and bullet fragments near the treatment area. The same guidance calls for close monitoring of patients with a history of seizures, stroke, or head injury.

Before your first session, our screening covers:

1. A review of any implants, devices, or metal in or near your head
2. Your seizure history and any neurological conditions
3. Screening for bipolar spectrum conditions, which can affect how you respond to stimulation
4. Your current medications, including any recent changes or doses you have stopped
5. Alcohol and substance use, sleep patterns, and other factors that can affect your seizure threshold

We then map your individual motor threshold, the lowest stimulation level that produces a small movement in your hand. That measurement sets your treatment dose, which keeps stimulation strong enough to help without going higher than you need.

Tell us right away. Some patients notice a temporary increase in low mood, anxiety, irritability, or fatigue partway through treatment, often called the TMS dip. For most people it lasts a few days to roughly two weeks and is not a sign that treatment is failing.

When you report a change, we assess it the same day. That includes a safety check, a review of your medications and any recent changes, and a look at your coil placement and stimulation settings. Depending on what we find, we may continue with closer monitoring, pause briefly and reassess, or adjust your protocol.

Physical side effects get the same attention. If a headache is lingering or scalp discomfort is not easing, small changes to positioning or settings often make sessions more comfortable. You never need to push through discomfort quietly.

If you are ever in immediate danger or having thoughts of harming yourself, call 911, or call or text 988 to reach the 988 Suicide & Crisis Lifeline, available 24/7.