What Are the Side Effects of Brainwave Entrainment?

Introduction

Brainwave entrainment is popular in the wellness and personal development world. From meditation apps to productivity tools, it is promoted as a way to focus, relax and sleep better. As with anything that aims to affect your brain, it makes sense to ask what the side effects might be.

If you are curious, or a little skeptical, you are not alone. This guide covers what entrainment is, what people hope to get from it and the possible downsides to know about before you press play on a binaural beats track.

Understanding Brainwave Entrainment

What is brainwave entrainment?

Brainwave entrainment uses rhythmic sound, light or touch in the hope of synchronizing your brainwaves with a specific frequency. The idea is that by “training” your brain to match certain frequencies, you can encourage mental states such as deep relaxation, focus or sleepiness.

Types of brainwave entrainment

Binaural beats

Binaural beats are created when two pure tones of slightly different frequencies are played separately to each ear, one to the left and one to the right, using headphones. Your brain perceives a third “phantom” tone, the binaural beat, that is not in the sound itself. A 300 Hz tone in the left ear and a 310 Hz tone in the right ear, for example, produce a 10 Hz beat. The difference between the two tones is what creates the perceived beat. This perception happens in the brain, not in the ears, and headphones are needed to deliver a separate tone to each ear.

Isochronic tones

These are single tones that turn on and off rapidly at set intervals. Many people find them more intense than binaural beats.

Monaural beats

Unlike binaural beats, monaural beats use two tones mixed together before they reach your ears, so you can listen with one ear only and still hear the pulse.

How it works on the brain

The brain’s electrical activity moves between frequency ranges called delta, theta, alpha, beta and gamma. Researchers often use EEG to look at changes in this activity. The entrainment idea is that an external rhythm, such as sound or light, may nudge brainwaves toward a target frequency range and so affect mood, focus and relaxation.

A 2023 systematic review tested this idea for binaural beats in 14 studies. Five reported results in line with the entrainment idea, eight reported contradictory results and one reported mixed results. So the effect on brain activity is not settled.

Benefits of Brainwave Entrainment

People who use entrainment report the benefits below. These are personal reports, and research results are mixed.

Stress reduction

Alpha and theta tracks are popular for creating a calm, meditative feeling, which some people find helps with relaxation and stress.

Improved focus and productivity

Some people use beta and gamma tracks to feel more alert and concentrated.

Better sleep quality

Some listeners use delta tracks to help them drift off.

Mood enhancement

Some people say their mood feels lighter after listening, though this is an individual experience.

Common Side Effects

Headaches and migraines

Overstimulation can cause tension headaches, especially with high volume or long sessions. Intense pulses of sound or light can sometimes trigger headaches or migraines in sensitive people.

Dizziness or lightheadedness

Some people feel “off balance” for a while afterwards. Flickering or strobe lights can also cause dizziness or lightheadedness, particularly in people who are sensitive to visual stimuli.

Anxiety or restlessness

Oddly, tracks meant for relaxation can leave some listeners uneasy.

Irritability

Some people report feeling unusually irritable after listening, possibly because of overstimulation.

Tinnitus or ear discomfort

Loud tones or long periods of headphone use can strain your ears.

Difficulty concentrating

After a deep relaxation session, some people feel mentally “foggy” for a short time.

Rare but Possible Side Effects

Seizure risk in epilepsy patients

The NHS advises people with epilepsy to keep a diary of possible seizure triggers and gives flashing lights as one example. Anyone with a history of seizures should avoid brainwave entrainment unless a doctor supervises.

Disorientation or confusion

Some people report feeling disoriented after a session.

Emotional sensitivity or mood swings

Some people say certain tracks bring strong feelings to the surface.

Vivid or disturbing dreams

Some listeners who use delta or theta tracks report more intense dreams, which can be pleasant or unpleasant.

Factors That Influence Side Effects

Session duration and frequency

Long or frequent sessions are more likely to leave you tired or overstimulated.

Volume and intensity of tones

Louder is not better. High volume is a common cause of discomfort.

Individual brain sensitivity

Some people are naturally more sensitive to sound and light than others.

Underlying mental or neurological conditions

If you live with a mental health or neurological condition, such as PTSD, ADHD or an anxiety disorder, talk to your doctor before trying entrainment.

Safety Guidelines

Start slow and short

Begin with 10 to 15 minute sessions to see how your body reacts.

Use safe volume levels

Keep your device at a comfortable listening level.

Avoid during certain activities

Never use entrainment while driving, operating machinery or doing anything that needs your full alertness.

Consult with a healthcare professional

This matters especially if you have a neurological condition or mental health concerns.

Who Should Avoid Brainwave Entrainment

People with epilepsy

Even visual entrainment methods involve flickering light, which is why people with epilepsy should avoid them without medical advice.

Those prone to migraines

Intense frequencies or flickering light could make symptoms worse, so be cautious.

Individuals with severe anxiety disorders

Some people feel uneasy with entrainment audio, so people with severe anxiety should speak to a professional first.

Pregnant women (as precaution)

As a precaution, check with your doctor before trying it during pregnancy.

How to Minimize Risks

Choosing the right type of entrainment

Some people prefer isochronic tones to binaural beats, and vice versa. Try one method at a time.

Using high-quality recordings

Poorly mixed tracks with harsh sounds can be unpleasant, so choose recordings from creators you trust.

Monitoring your reactions

Keep track of how you feel after each session.

Taking breaks between sessions

Give your brain time to reset.

Conclusion

Brainwave entrainment is a gentle practice for many people, but it is not without risks. The side effects people report vary, and knowing what to expect helps you use it safely. Start small, listen to your body and take a break if something feels off. Like any wellness practice, it works best when used with awareness and moderation.