Almost everyone considering TMS asks the same question first: what is this going to do to me? It is a fair question, and it deserves a straight answer rather than a reassuring one. The short version is that the common side effects of TMS are mild, local to the treatment site, and tend to fade within the first week or two. The serious risk people worry about is real but genuinely rare, and we can put a number on it.
The side effects most people actually get
Scalp discomfort at the treatment site
This is the most common one. The coil sits against your head and delivers rapid magnetic pulses, and the sensation is often described as tapping, knocking, or a tight pinching feeling on one spot of the scalp. It is most noticeable during the first few sessions, while the muscles and nerves in that area get used to it. For most people it becomes background noise within the first week.
If it stays uncomfortable, that is worth saying out loud rather than tolerating. Small adjustments to coil position, or easing the intensity up more gradually over the first several sessions, usually solve it.
Headache
Mild headache after a session is common early on and typically responds to an ordinary over the counter pain reliever. Like the scalp discomfort, it usually settles as treatment continues. Persistent or worsening headaches are not something to push through quietly, they are something to report.
Facial or jaw twitching during the session
The pulses can stimulate nerves that run to the muscles of the face and jaw, so some people notice twitching or tightening on one side while the machine is running. It stops when the session stops. It looks and feels stranger than it is, and it is not a sign that anything is going wrong.
What TMS does not do
Some of the most useful information about TMS is about what is not on the list.
- It does not cause memory loss or cognitive dulling. This is the point that matters most to people who are thinking of TMS in the same category as electroconvulsive therapy. They are different treatments. TMS does not induce a seizure by design, does not require anesthesia, and is not associated with the memory effects that can follow ECT.
- It does not require sedation. You are awake, sitting in a chair, and you drive yourself home afterward.
- It does not carry the systemic side effects of antidepressants. Because nothing is being absorbed into your bloodstream, the familiar medication trade offs, weight change, sexual side effects, emotional blunting, gastrointestinal upset, are not part of the picture.
The rare risk people ask about: seizures
This is the one that shows up in every internet search, so it is worth looking at the actual data rather than the general reassurance.
A large safety survey published in Brain Stimulation pooled 586,656 treatment sessions across 25,526 patients. The observed seizure rate was 0.31 per 10,000 sessions, which works out to roughly one seizure in every 32,000 sessions, or about 0.71 per 1,000 patients treated.
To put that in perspective, a standard course of TMS is around 30 to 36 sessions. The risk is low enough that it is not the deciding factor for most patients, but it is not zero, and it is the reason a proper screening conversation happens before anyone starts.
Who should not have TMS
Screening exists to catch a small number of specific situations.
- Non removable metal or electronic implants in or near the head. Aneurysm clips, cochlear implants, metal plates, stents or coils in the head or neck, and implanted stimulators or pacemakers all need to be reviewed before treatment. Dental fillings and most dental work are not a problem.
- A history of seizures or epilepsy. This does not always rule TMS out, but it changes the risk calculation and needs to be weighed carefully.
- Certain other neurological histories, including significant head injury or brain surgery, which are worth reviewing individually.
This is also why a full psychiatric evaluation matters before starting. Screening for TMS is not a form to sign, it is a clinical conversation.
Questions worth asking before you start
- Who is actually supervising my treatment, and will I see the same physician throughout?
- What device and protocol will I be on, and how long is each session?
- What do you do if the scalp discomfort does not settle after the first week?
- How will we measure whether this is working, and at what point do we reassess?
- What happens after the course finishes?
The honest summary
For most people, TMS side effects amount to a sore spot on the scalp and a headache for the first week or so, both of which fade. The serious risk is real, quantifiable, and rare. The more useful conversation is usually not whether TMS is safe, but whether it is the right next step for your particular history, which is a question that needs your full picture rather than a general answer.
If you are weighing it up, you may find it helpful to read how TMS therapy actually works, or to look at how TMS compares with medication. You can also learn more about TMS at our practice or request an appointment to talk it through.
This article is for general education and is not medical advice. Whether TMS is appropriate for you depends on your individual history and should be decided with a physician who has reviewed it.
Talk it through with someone
Jersey Shore Psychiatric Services provides psychiatric care for adolescents from age 12 and adults at 432 Avenel St, Avenel, NJ 07001. Care is led by Dr. Muhammad Ali Abbas, a triple board-certified interventional psychiatrist who directs the Neuromodulation Division at Raritan Bay Medical Center. Telepsychiatry is available for patients in New Jersey and New York, and new patients are usually seen within a day.
Call or text (732) 426-7030, email info@jshealth.org, or request an appointment online.