Most pages about neurofeedback side effects fall into one of two camps. Either they list nothing at all and call it “completely safe,” or they are written by someone with an axe to grind.
Neither is useful if you are actually deciding whether to try it. So here is the straight version, including why we will never use the phrase “no side effects.”
Start with what the procedure physically is
A lot of side-effect anxiety about neurofeedback comes from a picture people have in their heads of something being done to the brain. That is not what happens.
Neurofeedback is non-invasive. We record your brain’s activity through sensors placed on the scalp, and nothing is sent into the brain. No current, no stimulation, no medication. The sensors read the electrical signals your neurons are already producing, the same way a stethoscope listens to a heartbeat without doing anything to it. What changes during a session is the feedback you get about your own activity, not the activity being pushed from outside.
That is genuinely important for the risk picture, and it is why the reported effects below are as mild as they are.
What people actually report
It is generally well tolerated. Some people notice temporary tiredness, mild headache, or restlessness after a session, usually early in training. Tell us about anything you notice and we will adjust your protocol.
Those three, tiredness, mild headache, and restlessness, are the ones that come up consistently. They tend to appear in the earlier part of a course rather than later, and they tend to be short-lived rather than lingering.
One detail worth knowing: fatigue and restlessness are recognised markers of overtraining. They are not just discomfort to be tolerated, they are information. If they show up, the right response is to adjust the protocol, not to push harder through them. That is a large part of why training is supervised rather than something you buy and run at home unsupervised.
What the controlled trials found
Two recent trials tracked safety deliberately rather than as an afterthought, which makes them more useful than a general review.
A 2025 placebo-controlled trial published in Scientific Reports compared real neurofeedback with a placebo version in people with fibromyalgia. Its safety findings were direct: no serious adverse effects were reported. Several transient, low-intensity side effects were reported and rated as related to the training, and the most common in the active group were increased dreaming and fatigue after sessions. No participants discontinued the study because of side effects.
The increased-dreaming finding is an interesting one. It showed up more in the active group than the placebo group, and the authors raise the possibility that it reflects the brain doing something with the training rather than being a nuisance effect. That is a hypothesis, not a demonstrated mechanism, but it is a reasonable thing to mention if it happens to you.
A 2024 trial in Archives of Rehabilitation Research and Clinical Translation studied home-based EEG neurofeedback for chronic pain and logged every adverse event, including ones that had nothing to do with the training. Of 13 recorded events, only one was judged treatment-related: a participant reported a heavy feeling, tingling, weakness on one side, and fatigue during a session. It was graded moderate, and in her case the symptoms were ones she already experienced when anxious, which is why the trial team judged them as they did. The remaining 12 events were equipment problems or delivery and administrative issues. The authors’ summary: overall safety was good, with no serious adverse events recorded.
Do not use that trial report as a reason to wait. Sudden weakness, numbness, or tingling on one side of the body is a recognised warning sign of stroke and other time-critical conditions, and it needs emergency assessment, not a note to your neurofeedback provider. In that study the finding was investigated by clinicians and matched a symptom the participant already knew she had. You cannot make that call about yourself in the moment, and neither can we. If it happens to you, treat it as a medical emergency first.
Who should talk to a doctor first
Neurofeedback is training, not urgent care, and a few situations belong in front of a physician before or instead of a session.
Go to the ER or call 911 for weakness or numbness, slurred speech, a severe or worsening headache, a seizure, confusion, one pupil larger than the other, repeated vomiting, or trouble staying awake. Those are emergency symptoms whatever else is going on in your week, and neurofeedback is never the right first response to them.
Talk to your doctor before starting if you have a seizure disorder, a recent head injury that has not been medically evaluated, or a neurological or psychiatric condition under active treatment. A fresh concussion in particular is a medical matter rather than a training one, and we ask that it be evaluated first.
Keep your prescriber in the loop. If you take medication for a psychiatric or neurological condition, they should know you are training. Never change or stop a prescribed medication on your own.
And if something you notice during training worries you, tell us, and tell your physician. We would much rather look into a symptom that turns out to be nothing than have you sit on one because it seemed like it might be part of the process.
Why we still will not say “no side effects”
Two reasons, and one of them is about trust.
The first is that it would not be true. People do report things, as above. Saying otherwise means either you have not looked or you are hiding it.
The second is that the safety literature here is thinner than the efficacy literature. Look again at the two trials above: both were small, and both were built primarily to test whether the approach was feasible and safe rather than to measure how well it worked. That is where a lot of the safety evidence currently lives, in small studies with short follow-up.
A 2026 systematic review of the ethics of EEG neurofeedback in BMC Medical Ethics put a sharper point on the surrounding problem. Its conclusion was that ethical analysis “has not consistently kept pace with the technological expansion and commercial dissemination” of the technology, with persistent limitations identified in practitioner training and regulatory oversight. That is a fair criticism of this industry, and the honest response is not to paper over it with a reassuring claim. It is to say the gap exists, watch for effects in our own patients, and act on what we see.
“Completely safe” and “no side effects” are also exactly the kind of unsubstantiated safety claims that regulators pursue in health advertising. We would rather tell you about mild transient tiredness than make a promise nobody can back.
Where the regulatory line sits
Since it comes up alongside safety: neurofeedback is a procedure, not a drug, so it is not something the FDA approves. The EEG equipment used in biofeedback is regulated as a Class II medical device and has been cleared through the 510(k) pathway for indications such as relaxation training. Clearance is not approval, and it attaches to the equipment rather than to neurofeedback as a therapy for any named condition.
Neurofeedback is not FDA approved as a treatment for any specific condition, and it is not a cure.
What we ask of you
The single most useful thing you can do is tell us what you notice, including the vague stuff. “I was wiped out that evening” and “I felt wound up afterward” are both worth saying out loud, because both map onto known patterns and both are reasons to change something.
Training is guided by your own qEEG brain map rather than a generic protocol, which means there is something specific to adjust when your response suggests we should. We also work alongside your medical and mental health care rather than in place of it, so if something you notice belongs in front of your physician, we will say so.
If you are weighing this up and want the evidence picture as well as the safety picture, we wrote an honest read on whether neurofeedback actually works, including the conditions where the research does not support it.
Sources
- Anderson L, De Ridder D, Glue P, et al. A safety and feasibility randomized placebo controlled trial exploring electroencephalographic effective connectivity neurofeedback treatment for fibromyalgia. Scientific Reports. 2025;15. doi:10.1038/s41598-024-83776-8
- Feasibility and Safety of a Home-based Electroencephalogram Neurofeedback Intervention to Reduce Chronic Pain. Archives of Rehabilitation Research and Clinical Translation. 2024.
- Ethical challenges in EEG neurofeedback: a systematic review of gaps, risks, and responsibilities. BMC Medical Ethics. 2026.
- U.S. Food and Drug Administration, 21 CFR Part 882, Neurological Devices.
A little more clarity
Your questions.
Does neurofeedback have side effects?
Some people notice temporary tiredness, mild headache, or restlessness after a session, usually early in training. These effects are generally short-lived. We will not tell you there are no side effects at all, because that is not true and it is not a claim anyone can support.
Is neurofeedback painful or invasive?
No. Neurofeedback is non-invasive. We record your brain's activity through sensors placed on the scalp, and nothing is sent into the brain. The sensors only read the electrical activity your brain is already producing, the way a stethoscope listens to a heartbeat.
How long do neurofeedback side effects last?
When people do notice something, it is typically short-lived and tends to appear early in a course of training rather than later. Tell us about anything you notice, because tiredness and restlessness are recognised markers of overtraining and are a signal to adjust your protocol rather than push through.
When is a symptom an emergency rather than a side effect?
Sudden weakness, numbness, or tingling on one side of the body, slurred speech, a severe or worsening headache, a seizure, confusion, or trouble staying awake are emergency symptoms. Go to the ER or call 911. Do not wait to see whether they pass, and do not treat them as an expected part of training. Neurofeedback is never the right first response to any of those.
Have serious adverse events been reported in neurofeedback trials?
In the controlled trials that specifically tracked safety, no serious adverse events were reported, and participants generally did not drop out because of side effects. That is reassuring, though the safety literature is thinner than the efficacy literature and researchers have called for more systematic monitoring.