Are There Side Effects to Neurofeedback?
Updated: Oct 10
✓ Fact checked by: Dr. Glen M Doniger, PhD
Similar to most types of therapies, neurofeedback training may cause side effects. However, these side effects are mostly mild and don't last for too long.
Think of it this way: feeling tired after a workout at the gym is a side effect of exercising. Or is it a benefit? It's the same with brain training: the most common side effect of neurofeedback is fatigue, but that's usually a sign you are doing well.
And while brain training is comparable to physical training in many ways, the brain reveals the side effects of training differently than the body does.
For example, you may feel a similar mental fatigue level when you're learning a complex cognitive skill or after speaking in a non-native language, but these feelings are temporary and usually don’t last long.
While fatigue is probably the most common side effect, there are other mild ones that can occur. Such side effects may include:
Stress: You may experience nervousness about an electrode being attached to your head or feel anxious during the session, but there's nothing to worry about because neurofeedback is a safe and non-invasive procedure.
Headaches or dizziness: You may experience dizziness during or after the training, particularly when training faster (high-frequency) waves.
Distractedness: You may temporarily have trouble concentrating, but this symptom is usually mild and diminishes within a few hours after the session.
It’s important to state that reported side effects are rare, usually transitory, and not considered dangerous. These side effects are not permanent and tend to wear off quickly after the training but if you experience any of them, tell your neurofeedback expert about it so they can see what adjustments can be made to help you feel more comfortable.
What Does Neurofeedback Do to the Brain?
Neurofeedback training has been offered in clinical settings for decades for many different purposes. It’s a form of biofeedback that uses EEG technology to read your brainwaves in real time and shows you visual or auditory feedback based on your performance during protocols determined by your neurofeedback expert.
The goal of neurofeedback is to train the brain to regulate itself and help you understand when your brain is in the desired state so that, eventually, your brain may be able to maintain a more balanced state, even when it's not receiving feedback.
Will Neurofeedback Affect My Personality?
Neurofeedback training cannot change your personality. By doing neurofeedback, you're building new neural pathways and leveraging the networks in your brain to improve brain health.
While neurofeedback training may enhance your memory and focus, decrease impulsivity and anxiety, and help you achieve mental clarity, restful sleep, and improved mood, the process doesn't change your overall personality – it trains your brain to work more effectively.
Different Parts of the Brain React Differently to Training
Neurofeedback protocols target specific brain wave frequencies recorded at a certain location on your scalp. The training consists of increasing or decreasing these frequencies.
However, training at some sites can be especially challenging, and protocols involving these sites may have more frequent side effects.
For example, the sensorimotor rhythm (SMR) protocol that involves training over the central part of the brain (the “sensorimotor strip”) seems particularly prone to side effects. The SMR protocol is known to enhance attention and has been applied to improve cognitive performance, primarily for attention and memory gains.
In one study, participants who received an SMR protocol (targeting right-hemisphere site C4) reported experiencing headaches and tiredness during and shortly after the neurofeedback training but their symptoms were mild and temporary.
The Impact of Brainwave Frequency Changes
The theory behind neurofeedback is that by training brainwaves, you can improve the brain’s functioning - which can impact things such as thoughts, moods, and the ability to relax or concentrate.
Retraining certain areas of your brain to increase the frequency of beta waves is usually done to improve attention and focus, but it might have mild side effects.
Beta brainwaves are amplified when your brain is alert and engaged in cognitive tasks that require a lot of attention and focus. They are dominant during instances of problem-solving, judgment, decision-making, or any other focused mental activity.
You may feel somewhat anxious and experience difficulty sleeping following training to increase beta activity because it may be harder for you to relax.
On the other hand, when slower frequencies are the goal (training to increase delta or theta brainwaves), you may experience fatigue or have trouble concentrating because your brain might be in a deeply relaxed state. But these reactions are temporary and should dissipate as training continues.
Inform Your Neurofeedback Expert if You Have Neurological Conditions
It’s important to disclose your medical history to your practitioner before beginning neurofeedback therapy so that they can minimize the possibility of side effects by adjusting your protocol.
Let them know if you have any neurological conditions like epilepsy, traumatic brain injury, narcolepsy, or migraines, because some of these conditions may cause side effects like headaches, nausea, dizziness, fatigue, and agitation.
What You Can Do To Minimize Side Effects
Try reducing the likelihood of side effects from neurofeedback training by:
1) Choosing an experienced neurofeedback expert: An experienced practitioner knows the appropriate frequencies to use for your training protocol and the best regions of the brain to target.
2) Trying not to overwork your brain: Just as athletes can strain their muscles by exercising too much, you may overtax yourself by engaging in neurofeedback sessions that are too long or too intense.
3) Eating a healthy diet: Maintaining a diet that includes healthy fats, protein, and whole grains should minimize side effects like fatigue.
Consult Your Neurofeedback Expert
Part of your neurofeedback expert's responsibility is to ask you about possible side effects and record their frequency and severity throughout the training process. As training progresses, it’s always important to consistently provide feedback about what you’re experiencing.
It might be a good idea to keep a written journal where you can record side effects you may have experienced. You can share this information with your practitioner so they can adjust your protocol accordingly.
A neurofeedback expert may also monitor your brain activity during sessions so they can tell if your brain is responding appropriately to the training and adjust your protocol if needed.
Don’t forget the fact that any change, even a positive one, can be accompanied by other changes that you may or may not anticipate. You're trying to improve the way your brain functions and has functioned for years. This is not a simple task and may thus be accompanied by minor side effects, but these should subside as you continue to train.
So, keep track of your symptoms and listen to your body and the signals it's sending you. This way, you can ensure that neurofeedback training will leave you experiencing only benefits!
Dr. Doniger is a cognitive neuroscientist with two decades of experience in the neurotech industry. He holds a PhD from New York University and has been involved in studies of visual perception, cognitive training, neurofeedback, and neurostimulation using behavioral and neuroimaging techniques in a variety of research and clinical settings.