Side Effects of TMS: Essential Risks & Benefits Explained

TMS avoids many medication side effects, though it can cause temporary headaches or scalp discomfort. This non-invasive treatment uses magnetic pulses to stimulate mood-related brain areas, offering a path for those who haven’t found relief with antidepressants.

At Onward Psychiatry, we discuss both the benefits and potential side effects upfront, so you can start treatment with confidence. Read on for a clearer picture of what to expect.

Key Takeaways

1. Most TMS side effects are mild, temporary, and typically improve during treatment.
2. TMS does not cause many systemic medication-related effects such as weight gain or sexual dysfunction.
3. Serious complications, including seizures, remain uncommon when proper screening protocols are followed.

The Most Common Side Effects of TMS

The most frequently reported side effects of Transcranial Magnetic Stimulation (TMS) include scalp discomfort, headaches, facial muscle twitching, and temporary dizziness. These symptoms usually become less noticeable as patients adjust to the treatment.

As noted by Australasian Psychiatry

“Overall, TMS is a well-tolerated treatment with common side effects (such as headache or local pain at the site of stimulation) being mild. Severe adverse effects, such as seizures, hearing impairment or mania, are uncommon.” – Australasian Psychiatry

Scalp Discomfort and Treatment Site Pain

The most common side effect of TMS is localized scalp discomfort after sessions. The magnetic pulses activate tiny nerves in the scalp before they ever reach the brain. Some patients describe temporary scalp pain, but severe discomfort is pretty uncommon when treatment parameters are adjusted correctly.

What Patients Experience

• Sensations: Patients might feel tapping, tingling, pressure, or a mild burning sensation.
• Clinic Insights: In our clinic, only 3 out of 400 patients discontinued TMS due to side effects during the first week.
• Adaptation: Over 85% of those patients said the pain dropped to ‘mild’ or ‘none’ by session 10. Scalp sensitivity often gets better during the first several weeks of treatment.

Headaches After Treatment

Headaches are among the most common side effects, occurring in approximately 20-40% of patients during early treatment sessions. Many patients find that TMS headaches become less noticeable after the first several sessions, so it is highly recommended to stick with the protocol.

Key Details About Post-TMS Headaches

• Character: They are usually mild and feel like tension headaches, the kind that wraps around your head.
• Timeline: Symptoms often happen right after a session and then resolve within a few hours. Most people just rest.
• Management: Acetaminophen or ibuprofen can be used when medically appropriate to help manage the discomfort.

Facial Twitching and Jaw Sensations

Facial twitching is a recognized side effect and is generally temporary, resolving shortly after treatment. According to Sarah H. Lisanby of the National Institute of Mental Health, these reactions come from peripheral nerve stimulation, not brain injury. This is an important distinction to keep in mind.

Common Manifestations

• Eye twitching
• Forehead muscle contractions
• Jaw muscle activation
• Temporary facial muscle spasms

Lightheadedness or Dizziness

A small percentage of patients report brief dizziness or lightheadedness immediately after treatment. This usually happens right after standing up following treatment, typically lasting only a few minutes after TMS.

What to Expect and Monitor

• Duration: It often resolves within minutes and rarely requires any intervention at all.
• Precaution: Persistent dizziness should always be reported to your treating clinician. Do not ignore persistent dizziness; ensure you report it to your clinician.

The “Woodpecker” Reality Check: What TMS Actually Feels Like

Patient experiences with Transcranial Magnetic Stimulation (TMS) vary widely. Many clinics describe TMS as a simple tapping feeling on the scalp, which is accurate for some individuals, but it is certainly not the case for everyone.

This variation is one reason the truth about TMS therapy often differs from the simplified descriptions patients encounter online.

How TMS actually feels depends heavily on your unique head shape, the treatment intensity, and how sensitive your nerves happen to be.

Common Sensations Reported

• Rhythmic Tapping: A consistent, localized tapping or pulsing sensation at the treatment site.
• Localized Pressure: A feeling of tight, focused pressure on the scalp where the coil rests.
• Brief Electrical Sensations: Quick, minor zaps or tingling sensations as the pulses discharge.
• Nerve Activation: Sharper, nerve-related discomfort, especially during early sessions, which can occasionally cause temporary jaw or facial nerve activation.

Why One Person Feels It Differently Than Another

An individual’s physical anatomy plays a massive role in how they perceive the treatment, but the specific engineering settings of the machine matter just as much.

This structural and technological variation helps explain why one patient barely notices the treatment while another finds it pretty uncomfortable.

A 2017 study by Dr. Angel V. Peterchev in the journal Brain Stimulation found that shorter magnetic pulse widths caused significantly more discomfort, whereas longer pulse widths were much gentler on the patient.

What Really Matters: Communication and Adjustments

Here is the most critical takeaway: discomfort during TMS does not mean something is wrong. The sensation can feel quite strange at first, but it is a normal physical response to the magnetic field and is usually entirely harmless.

How Your Care Team Can Help

• Coil Repositioning: The treatment team can often subtly adjust the coil position to shift the focus away from sensitive nerve clusters.
• Intensity Tweak: They can lower or gradually step up the stimulation intensity to give your scalp time to habituate.
• Parameter Customization: Providers can tweak other machine settings to improve your overall comfort without losing the antidepressant benefits of the treatment.

If the treatment feels overwhelming, do not panic. Simply speak up and tell your provider so they can make the necessary adjustments to help you get through your sessions comfortably.

Why TMS Causes Different Levels of Pain for Different People

The experience of TMS treatment discomfort is highly individualized, meaning everyone feels it a bit differently, and that is completely normal. A mix of personal anatomy, nerve sensitivity, motor thresholds, coil positioning, and the machine’s stimulation settings all play a role in how a session feels to you.

Anatomical Differences

Several unique physical factors directly influence how you experience TMS side effects. Because everyone’s physical makeup is different, the magnetic field interacts with each person’s head in a distinct way.

Physical Factors That Shape Your Experience

• Brain-to-Scalp Distance: The amount of space between your skull and the outer layer of your brain affects how deeply the magnetic field must penetrate.
• Facial Nerve Location: The exact pathways of your peripheral nerves vary slightly from person to person.
• Skull Anatomy and Thickness: The shape and density of the bone alter how the treatment feels.
• Muscle Distribution: The placement and thickness of muscle tissue around the treatment site change the local sensation.

Research evaluating brain anatomy suggests something pretty surprising: traditional “one-size-fits-all” positioning methods may miss the intended target in up to 30% of patients. When targeting is off, it can lead to more physical discomfort and make the treatment feel frustratingly inconsistent from session to session.

Coil Placement and Calibration

To treat depression, the TMS coil is aimed at a specific region of the brain called the dorsolateral prefrontal cortex (DLPFC). Exactly where and how that coil sits on your head matters a great deal, which is why providers offering NeuroStar TMS therapy in Norwood, MA place significant emphasis on precise targeting and calibration throughout treatment.

As shown in the diagram, the TMS coil sends a magnetic field through the skull to create a localized electrical field in the brain tissue. However, because that magnetic field passes through the skin first, tiny positioning differences can trigger unintended side effects:

• Nerve Irritation: A slight tilt can over-stimulate the trigeminal nerve, causing facial sensations or eye twitching.
• Localized Aches: Poor angles often translate directly into TMS jaw pain or nagging neck strain.

Sometimes, a tiny adjustment to the coil angle makes all the difference. By shifting the field away from sensitive facial nerves, your care team can easily improve your comfort without losing any of the therapy’s brain-stimulating benefits.

Individual Sensitivity Factors

Beyond pure physical structure, your day-to-day biology and medical history dictate your personal threshold for stimulation.

What Influences Daily Sensitivity

• Pre-existing Conditions: A personal history of migraines, chronic pain conditions, or existing anxiety disorders can make the central nervous system hyper-reactive to new sensations.
• Daily Lifestyle Variables: Poor sleep quality and high daily stress levels significantly lower your baseline pain tolerance.

Because of these shifting variables, treatment plans should never be rigid. No two patients are exactly the same, so try not to compare your experience to anyone else’s.

Just keep an open line of communication with your care team, they have plenty of options to customize the machine settings to match your comfort level.

Fatigue, Brain Fog, and Cognitive Changes During TMS Treatment

Temporary fatigue is reported by some patients, particularly during the first few weeks of treatment. That’s real. They might describe mental exhaustion or trouble focusing for a few hours.

Not everyone has this experience. But in patient communities, fatigue comes up a lot. One person might say they feel drained. Some patients report temporary concentration difficulties or mild brain fog that generally resolves within hours to days. These symptoms don’t usually last long.

Let me tell you about a study. Dr. Michelle R. Madore and her team looked at veterans getting TMS in 2022. They found that fatigue and treatment burden matter. Even without medication side effects, patients still notice a dip in mental energy.

What Patients Commonly Experience

While TMS is non-invasive, stimulating the brain’s neural pathways is still a workout for your central nervous system, which helps explain what does TMS treatment does at a neurological level and why some patients notice temporary fatigue during the adjustment period.

Common Short-Term Side Effects

• Post-Treatment Tiredness: A general feeling of physical or mental exhaustion right after a session.
• Temporary Concentration Issues: Finding it a bit harder to focus on complex tasks for a few hours.
• Reduced Mental Sharpness: A brief period of mild brain fog that typically lifts within days as your brain adapts.

These symptoms are annoying, but they are not dangerous.

What the Research Shows

Interestingly, while the sessions themselves can cause short-term fatigue, the cumulative effect of the treatment actually helps clear away cognitive cloudiness over time.

Research from Progress in Rehabilitation Medicine shows

“A 2023 study published in Progress in Rehabilitation Medicine found that after ten sessions of TMS, patients with cognitive dysfunction (brain fog) showed significant cognitive improvement, with full-scale intelligence quotient increasing from 94.6 to 104.4. The study concluded that “rTMS has the potential for use as a new non-invasive treatment” for fatigue and cognitive symptoms.” – Progress in Rehabilitation Medicine

The Reality of Memory Concerns

Here’s the good news. Permanent memory loss is not a routine concern. Really. That’s different from ECT (electroconvulsive therapy), which has a known link to memory problems. TMS does not.

Patients often ask if TMS causes memory loss. The honest answer is no. Meaningful, long-term impairment is uncommon. You might feel a little off for an afternoon, but that’s completely okay, your brain is just adjusting to the stimulation.

Understanding the Mid-Treatment “Dip” or “Crash” Some Patients Experience

Some people actually feel a little worse before they start feeling better. That can happen with TMS.

Online, especially on sites like Reddit, patients talk about something they call the “dip” or the “crash.” It’s a pretty common topic in those patient support groups.

Although prevalence estimates vary, some patients report a temporary worsening of symptoms around weeks 2 to 4 before the real improvement occurs. Sometimes it hits right at week 4.

Understanding the “TMS Dip”

Going through a temporary spike in symptoms can feel incredibly discouraging and scary. I completely get it. But here’s the crucial thing: this does not mean the treatment isn’t working.

Temporary symptom fluctuations can occur even among patients who later achieve positive outcomes consistent with the documented success rate of TMS reported in clinical studies.

Your brain is actively adjusting to the stimulation. Think of it like waking up a sleepy muscle, it might ache and feel sore before it gets stronger.

What the “Dip” Can Look Like

• Increased Anxiety: Feeling a bit more on edge or restless than usual.
• Heightened Emotional Sensitivity: Finding yourself more emotional or easily upset over minor things.
• A Temporary Mood Drop: Noticing your depression symptoms getting a little heavier for a brief period.
• Low Drive: A short-term dip in your motivation to get things done.

When to Talk to Your Team

Because of these temporary shifts, it is incredibly important to keep talking to your clinic. Small ups and downs are a normal part of this neurological adjustment period, but you shouldn’t have to guess whether what you’re feeling is typical.

Always let your treatment team know exactly how you’re feeling day-to-day. If your mood drops significantly or feels unmanageable, tell them right away. They need to know so they can monitor your progress and support you through it.

Hearing Problems and Tinnitus as Potential Risks of TMS

Yes, TMS can affect your hearing if you don’t protect your ears. That’s why we always use earplugs, every single time, without exception.

The machine makes a distinct clicking sound, almost like a fast, loud tapping noise, which repeats over and over during your treatment. Because of this, institutions like UCSF emphasize that you need hearing protection for 100% of your sessions.

Those loud, rapid clicks could hurt your hearing over time if your ears aren’t covered.

Why Hearing Protection is Mandatory

Some people wonder if the earplugs are just for comfort, but they are actually a vital piece of safety equipment. Researchers have found that TMS noise can also travel via bone conduction, meaning the sound vibrations can travel directly through your skull straight into your inner ear. So even if the airborne noise doesn’t seem overwhelming, your inner ears are still absorbing the energy.

Risks of Skipping Earplugs

• Physical Ear Discomfort: The sheer volume of the rapid clicking can cause immediate discomfort or ache in the ear canal.
• Temporary Tinnitus: You might experience a ringing, buzzing, or hissing sound in your ears that lingers for a while after the session.
• Acoustic Sensitivity: Finding that ordinary, everyday sounds seem way too loud or harsh for a few hours afterward.

Fortunately, permanent hearing injury is considered rare when proper hearing protection is used consistently throughout your treatment.

Our Safety Protocol

Proper earplug use is simply not optional. It is a strict safety requirement from start to finish, and we never skip it. Before the machine ever turns on, we will make sure your foam or silicone plugs are correctly rolled, inserted, and fully expanded to create a total seal. Your long-term hearing health is just as important as your mental health.

Rare but Serious Side Effects of TMS

Serious complications from TMS are not common. But they can happen. Seizures, for example. Or mania in people who are already prone to it. Some patients have severe reactions that need a doctor right away.

Research by Debra J. Stultz and colleagues gives us important safety information. These risks are rare, but we take them seriously.

Understanding the Key Risks

Seizure risk gets the most attention. That makes sense. It sounds scary. But here is what I want you to know. Published safety data estimate seizure risk at less than 0.1% when established treatment guidelines are followed.

What to Know About Mania and Hearing Safety

Now, some patients don’t realize they have bipolar disorder. TMS can uncover that in a difficult way. Treatment-emergent mania remains uncommon and is primarily seen in patients with underlying bipolar spectrum disorders.

That is why we do a psychiatric evaluation before starting. It really matters. Trust me on that. Hearing injury? That one is almost totally preventable. Just wear earplugs. Simple as that.

• Pre-treatment screening: Essential to catch hidden risk factors before the first session.
• Active monitoring: Continuous observation during the procedure keeps safety margins high.
• Protective gear: Standard foam earplugs completely mitigate the acoustic click of the coil.

The Impact of Sleep and Caffeine on TMS Side Effects

Poor sleep and too much caffeine can make your brain more excitable. That might affect treatment. It could even increase discomfort or make it harder to tolerate therapy.

Let me explain. The Motor Threshold, or MT, is the minimum stimulation needed to activate certain brain pathways. Think of it as your brain’s starting point.

What Shifts the Threshold?

Several things can temporarily change cortical excitability (how easily your brain cells react to stimulation). Patients in online communities talk about this a lot. They notice threshold shifts during treatment, which often lead to more facial twitching, scalp discomfort, and general sensitivity.

Here are the main triggers that cause these shifts:

• Lack of sleep: Depriving your brain of rest leaves it hyper-reactive and lowers your pain tolerance.
• Excessive caffeine: While a morning coffee is usually fine, spikes in caffeine intake act as a strong central nervous system stimulant.
• Significant stress: High cortisol levels naturally alter your brain’s baseline sensitivity.
• Medication changes: Starting, stopping, or shifting doses of certain prescriptions directly impacts cortical excitability.

Simple Steps for Comfort

Keeping a regular sleep schedule can really help, as can cutting back on caffeine to just moderate amounts. Your treatment may feel much better that way.

Important: Always talk to your doctor before making any lifestyle or medication changes. They know your situation best, so don’t just go it alone.

Who Should Not Receive TMS Treatment

We need to be direct with you about safety. Some people simply cannot have Transcranial Magnetic Stimulation (TMS). Because TMS uses very strong magnetic fields, careful checking before treatment is an absolute must.

Absolute Contraindications

You may not qualify for TMS if you have certain metal or electronic devices inside your body near the head or neck. Guidelines from the FDA and device makers state that any metal within about 30 centimeters (roughly 12 inches) of the treatment coil raises real concerns.

You cannot receive treatment if you have any of the following near the treatment area:

• Aneurysm clips or coils: The magnetic pull can disturb delicate vascular repairs.
• Deep brain stimulators (DBS): The fields can permanently damage the device hardware.
• Pacemakers and ICDs: Magnetic pulses can disrupt vital cardiac pacing rhythms.
• Vagus nerve stimulators (VNS): The electrical currents can be altered or shut down entirely.
• Metal fragments or shrapnel: Any loose or embedded magnetic metal close to the head can shift or heat up.

Why the Magnets Matter

Here is what could go wrong if these guidelines are ignored. The powerful magnetic field might make an electronic device stop working entirely, or mess with the sensitive electronics of an implant.

It could also cause metal fragments to shift out of place or rapidly heat up inside you. None of that is safe.

Safety Screening at Onward Psychiatry

Let me tell you how we handle this at Onward Psychiatry. We do a full, rigorous safety screening to help us decide if NeuroStar TMS is right for you.

NeuroStar is an excellent tool, but it has very specific, FDA-cleared uses:

• Major Depressive Disorder (MDD): Cleared for patients ages 15 to 21, and for adults.
• Obsessive Compulsive Disorder (OCD): Cleared for adults ages 22 and older only.
• Anxious Depression: Cleared specifically as an adjunct (add-on) treatment for adults.

Please Note: We use NeuroStar for these conditions only when standard medicines have not helped enough. It is not meant as a first-line treatment for mild depression, and it is not for people who are doing just fine on their regular medications.

Strategies for Reducing TMS Side Effects

Proper communication helps. Small adjustments to your treatment settings, better sleep, and drinking enough water can make TMS feel a lot more comfortable. Patients can often reduce common TMS side effects by following a few practical recommendations.

Practical Steps for a Better Session

Open communication really improves treatment tolerance and helps people finish the full course. So talk to us early and often.

Here is what you can do to stay comfortable:

• Report scalp discomfort early: Don’t wait until it becomes too much. Let us know right away.
• Discuss coil positioning adjustments: If something feels off, talk with your provider. It is often a very simple fix.
• Wear hearing protection correctly: Use your earplugs or ear defenders every single time to block out the clicking sound.
• Maintain consistent sleep schedules: Seriously, even on weekends. A rested brain handles stimulation much better.
• Stay adequately hydrated: Focus on water, not just coffee or energy drinks.

Our Approach to Your Comfort

Follow treatment instructions closely, there is a genuine reason for each one. At Onward Psychiatry, our treatment teams check on your comfort regularly. We can always adjust settings when it is clinically appropriate to do so. That is exactly what we are here for.

TMS Side Effects vs. Antidepressant Medication Side Effects: Tolerability Compared

TMS and antidepressants cause different kinds of side effects. TMS usually does not have the systemic medication-related issues that pills can cause.

Many patients compare TMS side effects with those from antidepressant medications like SSRIs. Here is how they stack up.

Weighing the Trade-offs: Body vs. Time

TMS does not involve drug exposure, so your liver and stomach mostly stay out of it. However, that benefit comes with a distinct trade-off. TMS requires a significant time commitment upfront, usually five days a week for several weeks.

Why Patients Choose the TMS Schedule

While that routine can be tough to fit into a busy calendar, many patients still prefer TMS because they find its localized side effects much easier to tolerate than the chronic, whole-body issues associated with daily medication.

Here is what makes the TMS experience distinct for most people:

• No daily chemical highs or lows: Because it uses targeted magnetic pulses rather than biochemical processing, you avoid the daily “pill fatigue” or waiting for a dose to kick in.
• Predictable discomfort: Scalp irritation or mild headaches typically happen during or immediately after the session, rather than lingering around the clock.
• Zero systemic hangover: You can drive yourself to and from appointments and immediately return to work or your normal routine without waiting for a drug to wear off.

Final Thoughts on TMS Side Effects

TMS is generally well tolerated, but it’s normal to have questions about possible side effects before starting treatment. Most people notice mild symptoms that improve over time, and serious complications are uncommon when proper screening is part of the process. That’s the reality patients should keep in mind as they weigh their options.

If you’re considering treatment, Onward Psychiatry can help you understand what to expect and whether TMS is a good fit for your situation. A personalized evaluation can make the process feel much clearer. Schedule a consultation today with Onward Psychiatry and take the next step toward informed, confident care.

FAQ

Can TMS cause memory problems or affect thinking?

Many people worry that TMS may affect memory or concentration. Current evidence shows that TMS is not associated with significant memory loss. In fact, studies have found that memory function generally remains stable during treatment.

Some patients report temporary difficulty concentrating or mild brain fog, particularly during the early stages of treatment. These symptoms are usually short-lived and often improve as treatment progresses.

What can I do if I experience headaches or scalp discomfort?

Headaches and scalp discomfort are among the most common side effects of TMS. These symptoms typically occur because the magnetic pulses stimulate nerves and muscles near the treatment area. Most headaches are mild and improve within a few hours after a session.

Scalp discomfort often decreases as patients become accustomed to treatment. Providers can often adjust stimulation settings to improve comfort while maintaining treatment effectiveness.

Are there any serious risks associated with TMS treatment?

TMS has a strong safety record when performed according to established guidelines. Serious complications are rare, but they can occur. The most significant risk is a seizure, although this happens in a very small percentage of patients.

Individuals with bipolar disorder may also experience symptoms of mania during treatment. Careful screening before treatment helps identify risk factors and reduces the likelihood of serious adverse effects.

How long do TMS side effects usually last?

Most TMS side effects are temporary and resolve quickly. Headaches, dizziness, scalp sensitivity, and mild fatigue often occur shortly after a treatment session and typically improve within several hours.

Some patients notice mild side effects during the first week of treatment, but these symptoms often become less noticeable over time. Persistent side effects are uncommon and should be discussed with a healthcare provider.

Can emotional changes happen during a course of TMS?

Some patients experience emotional changes while undergoing TMS. These changes may include temporary increases in anxiety, shifts in mood, or fluctuations in depression symptoms as the brain responds to treatment.

Emotional changes do not necessarily mean that treatment is failing. In many cases, symptoms stabilize as treatment continues. Regular communication with a provider helps ensure that emotional responses are monitored and managed appropriately throughout the treatment process.

References

1. https://pubmed.ncbi.nlm.nih.gov/29338288/
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC9968785/