Red light therapy can cause a headache in some people, but headaches are not considered a common reaction when a low-level LED device is used correctly. A headache after treatment may relate to light sensitivity, migraine, eye strain or excessive exposure. It may also happen at the same time as treatment without being caused by the device. Evidence does not establish how often headaches occur with consumer red light therapy devices.
Red Light Therapy and Headaches: At a Glance
| Question | Short answer |
|---|---|
| Can red light therapy trigger a headache? | Yes, particularly in people who are sensitive to light or prone to migraine. |
| Is headache a common side effect? | It is not known to be common. Correctly used red light therapy appears to have a favorable short-term safety profile. |
| What should you do if it happens? | Stop the session, move away from the light and do not repeat the same treatment until you understand the possible cause. |
| When is it urgent? | Seek immediate medical care for a sudden severe headache, vision changes, weakness, confusion, speech problems, seizure, fever or stiff neck. |
Why Can Red Light Therapy Cause a Headache?
Bright Light Can Worsen Migraine or Photophobia
People with migraine may experience photophobia, or sensitivity to light. Bright or visually uncomfortable light can worsen an existing migraine and may trigger an attack in some people. Flickering light can also be difficult to tolerate.
A red light therapy mask or panel can cause discomfort even though it does not emit ultraviolet light. Red light is not automatically comfortable for every user.
Light sensitivity can also be an early symptom of a migraine. A headache may already be developing when the person notices that the red light feels unpleasant.
Eye Exposure May Cause Discomfort
Masks and panels used close to the face can expose the eyes to bright LEDs. Looking directly at the lights, keeping the eyes open during treatment or skipping the recommended eye protection may contribute to eye discomfort or visual strain.
The U.S. Food and Drug Administration warns that light-based procedures can injure the eyes and recommends suitable eye protection when the device or treatment requires it. The FDA also distinguishes low-level photobiomodulation from more powerful light-based procedures, which carry greater heating and eye-safety concerns.
Excessive or Incorrect Use May Increase Discomfort
Red light therapy devices differ in wavelength, power, treatment distance and session length. Using a device closer, longer or more often than the manufacturer recommends may increase discomfort.
Cleveland Clinic states that red light therapy appears safe in the short term when used as directed, but misuse can damage the skin or eyes. The long-term safety of many at-home devices remains less certain.
Photosensitivity May Increase the Risk
Photobiomodulation may not be suitable for people with photosensitivity disorders or those taking photosensitizing medication. The FDA recommends checking these factors before using a light therapy device.
If a medication, medical condition or recent treatment has made you unusually sensitive to light, ask a healthcare professional before using a red light therapy mask or panel.
How Common Are Headaches During Photobiomodulation?
There is not enough evidence to give a reliable rate for headaches caused by ordinary consumer red light therapy devices.
A 2022 systematic review of photobiomodulation for primary headache reported no adverse events in the included trials, but rated the evidence quality as low. A separate 2026 pilot trial of transcranial near-infrared photobiomodulation reported mild headaches in 7 of 43 participants. That treatment was directed at the head, so its findings should not be used to estimate the risk from every facial or body LED device.
An FDA review of one light-based medical device listed headache or migraine as a possible adverse event, including one case reported during the clinical study. Findings from one device do not establish the risk for every red light therapy product.
What Should You Do If Red Light Therapy Gives You a Headache?
- Stop the session immediately.
- Move away from the light and rest in a dim, comfortable environment.
- Do not repeat the same session length, intensity or distance until you understand what may have caused the reaction.
- Check the device instructions, including the recommended eye protection, distance and maximum treatment time.
- Avoid looking directly at the LEDs.
- Record what happened, including the device, wavelength if provided, session duration, distance and symptoms.
- Speak with a healthcare professional if the headache happens every time you use the device, lasts unusually long or feels different from your usual headaches.
Do not push through repeated headaches. A recurring reaction may point to migraine sensitivity, eye irritation, photosensitivity or a device that is not suitable for you.
Can Red Light Therapy Treat Headaches?
Red and near-infrared photobiomodulation has been studied as a possible treatment for some headache conditions. The evidence is still insufficient to recommend it as a dependable treatment. A systematic review found possible benefits but rated the certainty of the evidence as low and called for better clinical trials.
Red light therapy should not replace an established migraine or headache treatment plan.
When Is a Headache After Red Light Therapy an Emergency?
Seek immediate medical attention if a headache:
- Starts suddenly and is extremely severe
- Causes blurred vision, halos, double vision or vision loss
- Occurs with weakness, numbness, trouble speaking, confusion or loss of balance
- Happens with a seizure, fainting, fever or stiff neck
- Follows a head injury
- Occurs with severe eye pain, eye redness or major visual changes
These symptoms can indicate a serious medical problem. Do not assume they are a normal red light therapy reaction.
Bottom Line
Red light therapy can cause headaches, but the reaction appears uncommon. Stop treatment if a headache develops, follow the device instructions and seek medical advice if the reaction is severe, repeated or accompanied by visual or neurological symptoms.