“What are the side effects?” is one of the first questions people ask us when they’re considering TMS. It’s a fair question, especially if you’ve already been through a few antidepressants and dealt with side effects that made you want to quit.
Here’s a straightforward look at what’s common, what’s rare, how TMS compares to medication, and what the research says about its safety.
What Is TMS Therapy?
TMS stands for transcranial magnetic stimulation. It’s an FDA-cleared, non-invasive treatment for depression that uses magnetic pulses to stimulate the areas of the brain involved in mood regulation.
TMS is usually recommended for people who haven’t gotten enough relief from antidepressant medications. There’s no anesthesia, no medication circulating through your body, and it’s done in an outpatient office.
You can learn more about our TMS therapy program, or read about how TMS is used for OCD and anxiety.
Common TMS Therapy Side Effects
Most TMS side effects are mild, stay in the area being treated, and tend to fade as treatment goes on.
Scalp Discomfort or Tingling at the Treatment Site
The most common side effect is a tapping, tingling, or pressure sensation on the scalp during the session. It comes from the magnetic coil resting against your head. Most people find it mild and get used to it within the first few sessions.
Headache After TMS Sessions
Mild headaches are common, especially during the first week or two. They usually go away within an hour or two and can be treated with an over-the-counter pain reliever if needed. For most people, they become less frequent as treatment continues.
Facial Muscle Twitching or Jaw Tension During Sessions
Some people notice small muscle twitches near the treatment area, or a tightening in the jaw, while the pulses are being delivered. This is a normal response and isn’t harmful. Your treatment team can adjust the coil position or settings to make it more comfortable.
Lightheadedness After Treatment
A small number of people feel briefly lightheaded right after a session. It usually passes within a few minutes and isn’t a sign of anything serious. You can drive and go back to your normal day right after treatment.
Rare but Possible TMS Side Effects
Seizure
Seizure is the most serious possible risk of TMS, and it’s very rare, occurring in less than 0.1% of patients. We reduce that risk further by screening carefully before treatment starts, including a review of your personal and family medical history. TMS isn’t recommended for people with a seizure disorder or certain other neurological conditions.
Hearing Sensitivity
The TMS coil makes a loud clicking sound during sessions. Earplugs are provided as a standard precaution. Temporary changes in hearing have been reported in rare cases where ear protection wasn’t used.
What TMS Therapy Does Not Cause
A big reason people choose TMS is that it avoids many of the side effects that come with antidepressants. TMS does not cause:
- Weight gain
- Sexual side effects
- Sedation or mental fogginess
- Nausea or stomach problems
- Effects throughout the body, since it works directly on the brain rather than through the bloodstream
There’s also no risk of dependence or withdrawal.
How TMS Side Effects Compare to Antidepressant Side Effects
Antidepressants affect the whole body, so their side effects can include weight changes, sexual dysfunction, insomnia, nausea, and emotional blunting. For some people those side effects are mild or fade. For others they’re the reason they stop taking the medication.
TMS side effects are local and temporary, and they usually settle down within the first one to two weeks. For people who have had a hard time tolerating medication, that difference matters a lot.
Depression itself can cause a surprising range of physical symptoms. Read more in our post on the physical symptoms of depression.
What to Expect During a TMS Treatment Session
Here’s what a typical session looks like:
- You sit in a reclined chair while a magnetic coil is positioned against your scalp
- The device delivers a series of magnetic pulses. You’ll hear clicking and feel tapping or pressure on your head
- You’re awake and alert the whole time, with no sedation
- Most sessions last about 5 to 20 minutes, depending on the protocol and whether doing rTMS, iTBS, or an accelerated protocol
- You can drive yourself to and from appointments and go right back to your normal activities
A standard course of treatment is usually five sessions a week for four to six weeks.
Who Should Not Receive TMS Therapy?
TMS isn’t right for everyone, which is why we do a thorough evaluation before treatment begins. TMS is generally not recommended for people with:
- Metal implants in or near the head, such as cochlear implants, certain aneurysm clips, or deep brain stimulators
- A personal history of seizures or epilepsy
- Certain neurological conditions that increase seizure risk
Dental fillings and braces are generally not a problem. Your intake evaluation will cover all of this and confirm whether TMS is safe for you.
Is TMS Therapy Right for You?
TMS may be a good fit if you:
- Have been diagnosed with depression and haven’t responded well enough to one or more antidepressants
- Have had side effects from antidepressants that you couldn’t tolerate
- Want a treatment option that doesn’t involve medication
- Are looking for an evidence-based alternative to try next
A psychiatric evaluation can help you decide whether TMS is the right next step. Learn more about TMS therapy for depression or our adult psychiatry services.
Common Questions About TMS Therapy Side Effects
Is TMS therapy painful?
Most people don’t describe it as painful. The tapping on the scalp can feel uncomfortable at first, but it’s usually mild, and most people get used to it within a few sessions. If it bothers you, the settings can be adjusted.
How long do TMS side effects last?
Headaches and scalp discomfort usually last an hour or two after a session at most. They tend to be most noticeable in the first one to two weeks and fade from there.
Can TMS make depression worse?
It’s uncommon. A few people notice a short-term increase in anxiety, irritability, or low mood early in treatment. In people with bipolar disorder, there’s a small risk of triggering a manic episode. Your provider will check in with you throughout treatment so any changes are caught early.
Does TMS therapy affect memory or cognition?
No. TMS doesn’t cause memory loss or cognitive problems, and it doesn’t require anesthesia. You can go back to work or school right after a session.
What is the success rate of TMS therapy for depression?
Results vary from person to person. In real-world studies of people whose depression hadn’t improved with medication, roughly half or more saw a meaningful response, and about a third reached full remission. These results typically surpass what we see with antidepressants. For accelerated protocols, such as the SAINT protocol, the results are even higher. Your provider can talk through what to expect based on your history.
A Well-Tolerated Treatment With a Strong Safety Record
TMS is one of the best-tolerated treatments available for depression. For most people, side effects are mild, short-lived, and limited to the treatment session itself. Serious side effects are rare, and careful screening makes them even less likely. If medication hasn’t worked for you, or the side effects have been too much, TMS is worth a conversation. We’re happy to help you figure out whether it’s a good fit.