TMS Therapy Side Effects: A Complete Guide
Table of Contents
What Is TMS Therapy and How Does It Work?
Common Side Effects of TMS Therapy
Scalp Discomfort and Mild Headaches
Muscle Twitching and Facial Nerve Stimulation
Auditory Sensitivity and Sound Concerns
How Long Do TMS Therapy Side Effects Last?
Is TMS FDA Approved and What Does Safety Data Show?
What to Expect During TMS Treatment Sessions
Serious and Rare Adverse Events
How Long Does TMS Take and Managing Treatment Duration
Frequently Asked Questions
Last Updated: October 2, 2026
What Is TMS Therapy and How Does It Work?
Transcranial magnetic stimulation, or TMS, is a noninvasive neuromodulation treatment that uses magnetic pulses to stimulate brain cells in areas associated with mood regulation. The procedure involves placing a magnetic coil against your scalp, typically over the prefrontal cortex, which is the region involved in depression and mood control. When activated, the coil delivers brief magnetic pulses that generate electrical currents in the brain without requiring surgery or anesthesia.
Unlike medications that circulate through your entire body, TMS works locally on specific brain regions. Each treatment session lasts 30-40 minutes, during which you remain awake and alert. The magnetic pulses create a rhythmic tapping sensation on your scalp, and you can return to normal activities immediately afterward. At Newtown TMS, our physician-administered approach ensures precise targeting and personalized adjustment of treatment parameters to match your individual needs.
The FDA approved TMS for treating depression in 2008, and since then, clinical evidence has expanded to support its use for treatment-resistant depression, anxiety, OCD, and PTSD. The therapeutic mechanism involves stimulating neural pathways that have become underactive in depression, essentially "retraining" the brain's communication patterns. Most patients require a full course of treatment, typically 20-30 sessions over four to six weeks, to achieve meaningful improvement in depressive symptoms (pubmed.ncbi.nlm.nih.gov).
Common Side Effects of TMS Therapy
The vast majority of people who receive TMS at Newtown TMS have absolutely no side effects. This isn because of the personalized way that Dr. Woodall administers the treatment. He says, “I don’t want any of my patients to feel uncomfortable. Absolutely no-one should feel pain from the treatment. There’s a way to do that so the experience is helpful and pleasant.” That said, nationally the most frequently reported adverse events from TMS therapy are mild to moderate and temporary. Understanding what to expect helps you prepare mentally and physically for treatment. The side effects typically diminish as your body adapts to the magnetic stimulation over the first few sessions.
Scalp Discomfort and Mild Headaches
Scalp discomfort is the most common side effect, occurring in the majority of patients during their first few sessions. You may experience a tapping or thumping sensation directly under the magnetic coil, which some describe as similar to someone gently tapping on your head. This usually ranges from mild to moderate and is generally well-tolerated.
If someone were to have a side effect, a mild to moderate headaches can occur particularly after the first treatment session. These headaches typically feel like tension headaches and are localized to the treatment area. They usually resolve within a few hours to a day after treatment. Taking over-the-counter pain relief before or after your session can help manage this symptom. Most patients find that headaches become less frequent or disappear entirely as treatment progresses. Once again, at Newtown TMS, this is very rare.
Pro Tip Apply ice or a cold compress to your scalp for 10-15 minutes after treatment if you experience discomfort. Many patients find this simple step significantly reduces post-treatment soreness.
Muscle Twitching and Facial Nerve Stimulation
Involuntary muscle twitching in your face or scalp can occur during treatment sessions. This happens because the magnetic pulses stimulate not only brain cells but also facial nerve branches near the treatment site. The twitching is typically mild and stops immediately when the magnetic coil is turned off. If it occurs, the twitching will not hurt you.
Facial nerve stimulation may cause your eye to twitch or muscles around your mouth to contract briefly during the procedure.
Auditory Sensitivity and Sound Concerns
Because Dr. Woodall uses a CloudTMS device, there is very little noise associated with the treatment. This is because the magnetic coil is housed in a cooling system that other TMS devices used in other clinics don’t have. This cooling system is the same one used to cool spacesuits. It is very high tech. This cooling system makes the magnetic pulse cleaner with less noise. And, unlike other TMS units, the magnet does not heat up against the patient’s head. Here is an excellent review article on the research on TMS side effects: https://pubmed.ncbi.nlm.nih.gov/19833552/
How Long Do TMS Therapy Side Effects Last?
Again, most patients at Newtown TMS have no side effects at all. If one does experience a side effect fromTMS therapy, they are temporary and resolve quickly. Scalp discomfort and headaches typically fade within hours to a day after each session. As your body adapts to the magnetic stimulation over successive treatments, these adverse events often diminish significantly so that by week two or three of your treatment course, they don’t occur at all.
Is TMS FDA Approved and What Does Safety Data Show?
The FDA cleared TMS for treating major depressive disorder in 2008 based on clinical trial evidence demonstrating safety and effectiveness (the FDA). Since then, the agency has approved additional TMS applications for treatment-resistant depression, insomnia, obsessive-compulsive disorder, and migraine headaches. This regulatory pathway reflects decades of research supporting the safety profile of the procedure when administered by qualified professionals.
What to Expect During TMS Treatment Sessions
A typical TMS session begins with you sitting in a comfortable reclined chair in a calm clinical environment. Your treatment team will position the magnetic coil against your scalp, usually over the left prefrontal cortex, which is the standard target for depression treatment. They will take measurements to ensure precise placement and may mark the spot with a pen for consistency across sessions.
Patient sitting in a medical chair during a TMS session..
Key Takeaway TMS treatment is an outpatient procedure with no downtime. You can schedule sessions around your work schedule and resume normal activities immediately afterward, making it practical for working professionals.
Serious and Rare Adverse Events
While serious side effects from TMS are exceedingly rare, it is important to understand the full safety profile. Seizure risk is the most serious potential adverse event, occurring in fewer than 1 in 30,000 patients. Seizure risk increases slightly in patients with a personal or family history of seizure disorders, which is why a thorough neurological assessment before treatment is essential. The reality is, TMS is a treatment for seizure disorder. It is when the clinician is inexperienced or not adequately trained to recognize the presence of risk factors that would result in a seizure: the wrong medication, sleep deprivation, the wrong pulse in the wrong location in someone with a seizure disorder. The odds of these all existing at the same time are exceedingly rare. A trained psychiatrist would catch this. At Newtown TMS we have treated seizure disorders in patients with TMS and medication adjustments.
How Long Does TMS Take and Managing Treatment Duration
A standard TMS treatment course typically requires 36 sessions delivered over six to seven weeks. Most patients attend sessions five days per week. Most patients experience benefit within the first 5 treatments. The research states that there is measurable benefit within 16 treatments, while others benefit from the full 30-session course. Here is a research reference: https://doi.org/10.1176/appi.neuropsych.16100181
Watch Out Do not expect immediate results. Most patients notice gradual improvement over two to four weeks of treatment. Expecting dramatic change after one or two sessions can lead to premature discontinuation before the full benefit emerges. Patience and consistency are essential for TMS success. Many patients experience rapid improvement in the first few sessions. Others, not until late in the treatment, or even after the treatment ends. The bottom line: patience.
Frequently Asked Questions
What are the most common side effects experienced during TMS therapy?
Another version of this question would be, "how often do side effects occur wth TMS?" The research needs interpretation because the studies ask if the person has experienced anything at all. So, the slightest discomfort is reported as well as the worst and they are given equal weight in the report of side effects. Here's a study that reviews the side effects: https://www.google.com/search?q=https://doi.org/10.4088/jcp.v69n0208 The most frequent side effects are mild scalp discomfort, transient headaches, and muscle twitching at the treatment site. These occur in some patients during early sessions but typically diminish as treatment progresses. Auditory sensitivity and facial nerve stimulation are also reported. Almost all side effects are temporary and resolve within hours after each session. Serious adverse events are very rare when treatment follows established clinical protocols and proper patient monitoring occurs throughout the course. At Newtown TMS we have seen no serious side effects after thousands of individual treatments over more than 7 years. TMS has none of the side effects of medications: sexual side effects, seen in over 80% of those taking an antidepressant, do not happen with TMS, agitation, insomnia, weight gain do not occur with TMS. Only 27% of patients on an antidepressant experience relief from depression. With TMS, 67% of the most severe forms of depression experience complete remission of their depression while 83% experience significant benefit. Here is a research article about this: https://www.google.com/search?q=https://doi.org/10.1016/j.jad.2020.08.005
How long do TMS therapy side effects typically last?
Most side effects resolve within minutes to hours after each treatment session. Scalp discomfort and headaches usually fade by the end of the day. Some patients experience mild residual discomfort the following day, but this typically resolves quickly. The intensity of side effects often decreases as patients progress through their treatment protocol.
Is TMS FDA approved for treating depression?
Yes. The FDA has approved transcranial magnetic stimulation as a safe and effective treatment for treatment-resistant depression. Clinical trials and post-market surveillance data support its therapeutic efficacy and safety profile. The FDA approval process involved rigorous evaluation of adverse events, patient safety monitoring, and clinical outcomes.
Can TMS therapy cause cognitive decline or memory loss?
The reality is, TMS is used to improve cognitive functioning. Here is one of many studies that show this improvement: https://pubmed.ncbi.nlm.nih.gov/27885448/ At Newtown TMS we have treated patients with mild cognitive decline and even post-stroke patients and seen cognitive improvements. Clinical trial data does not support cognitive decline or permanent memory loss as a result of TMS therapy. Some patients report mild, temporary difficulty with concentration during active treatment, but this resolves after the treatment course ends. The noninvasive nature of TMS and its targeted application to the prefrontal cortex minimize risk to cognitive function. Patient monitoring throughout treatment helps identify any unexpected changes. Discuss any concerns about cognition with your physician before and during your treatment protocol.
What serious side effects or risks should I know about?
Serious adverse events from TMS are very rare when proper protocols are followed. The most significant risk is seizure. Patients with a history of seizure disorder or certain neurological conditions face higher risk and require careful neurological assessment before treatment. Other rare risks include hearing loss if proper ear protection is not used and complications from magnetic field exposure in patients with certain implants. Comprehensive patient safety monitoring and screening before treatment substantially reduce these risks. These serious side effects have never been seen at Newtown TMS.
How does physician-administered TMS improve patient safety compared to other delivery models?
Physician-administered TMS ensures continuous clinical oversight, real-time monitoring of patient response, and immediate adjustment of treatment intensity and frequency based on individual tolerance and therapeutic progress. A physician can perform thorough neurological assessment, identify contraindications, and respond to any adverse events during treatment sessions. This direct supervision supports better risk-benefit evaluation and personalized treatment protocols tailored to each patient's specific condition and medical history. Dr. Woodall personally administers every TMS treatment. He also uses this time with his patients to perform detailed medical assessments to be sure there are no hidden medical issues causing the depression. For example, he looks for metabolic, inflammatory, autoimmune, infectious, endocrine and other biological elements that can cause, worsen depression or cause it to be less available to treatment. This makes the TMS treatment that much more effective.
What should I expect during a typical TMS treatment session?
Each session typically lasts 15-20 minutes. You sit in a comfortable chair while the TMS coil is positioned against your scalp. You will hear clicking sounds as the magnetic pulses are delivered. Few patients experience scalp discomfort or mild twitching sensations during the session, but these are not dangerous. There is no anesthesia required, and you remain awake and alert throughout. After the session, you can return to normal activities immediately. The treatment protocol involves 36 sessions for just over 7 weeks.
How long does a full TMS treatment course take?
A typical TMS treatment course spans 7 weeks, with sessions conducted 5 days per week. Each session takes 15-20 minutes, making it feasible for working professionals to fit treatment into their schedule. Some patients require additional maintenance sessions after the initial course to sustain therapeutic benefits. Your physician will determine the specific treatment protocol duration based on your individual response and clinical needs.
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