Photobiomodulation: What are the possible side effects?

Photobiomodulation is a well-tolerated technique that has been validated by hundreds of clinical studies and is used in many medical and paramedical settings. However, like any form of biological stimulation, it can sometimes cause temporary reactions.

A technique that is generally very well tolerated

Photobiomodulation (PBM) uses specific wavelengths (red and near-infrared) to stimulate cells without heat or radiation. It is non-invasive and does not damage tissue.

👉 To understand how it works, see: Definition and Uses of Photobiomodulation

What are the possible side effects?

Mild and temporary reactions

• Localized redness or a sensation of heat
• A tingling or prickling sensation in the exposed area
• Mild fatigue or drowsiness after a session
• Less commonly: temporary headaches or visual disturbances

These effects are generally caused by stimulation that is too intense or lasts too long, especially during the first few sessions.

Do I need safety glasses?

• ❌ Not required if the light is not directed at the eyes.
• ✅ Recommended for prolonged exposure of the face or if you want to keep your eyes open.

How can you avoid any side effects?

Practical Tips

• Start with short sessions (5 to 10 minutes)
• Maintain the recommended distance (15–30 cm)
• Do not let the skin stick to the appliance
• Stay hydrated before and after your workout
• Do not repeat too often at first: see recommended frequency

Are there any contraindications?

Yes, there are certain situations that call for caution or restraint:

• Pregnancy (abdominal area)
• Photosensitizing medications
• Photosensitive epilepsy
• Active cancer, unless otherwise prescribed by a doctor

Photobiomodulation and Hypersensitivity

Some highly sensitive individuals (those with electromagnetic hypersensitivity or chronic inflammatory conditions) may experience paradoxical effects during the first few sessions.

💡 In that case, it is recommended to further reduce the intensity and duration, or to use pulsed modes with automatic shut-off.

Frequently Asked Questions

Can photobiomodulation have side effects?

They are rare. They may include temporary flushing, mild fatigue, or headaches. They go away on their own.

Should I wear glasses?

Not necessarily, unless you’re using the light on your face, very close to your eyes. Glasses can improve visual comfort.

How can you present yourself effectively?

Start slowly, follow the guidelines, stay hydrated, and make sure to space out your first few sessions.

Scientific sources cited

• Safety of photobiomodulation: a review – M. Hamblin et al. – 2018 – PMC
• Photobiomodulation in Clinical Dermatology: Safety Profile – Avci et al. – 2014 – PubMed
• Red and NIR light therapy: Biophysical mechanisms and risks – Rojas et al. – 2012 – PubMed

See also

• Photobiomodulation: Contraindications and Precautions
• At-home photobiomodulation: precautions to take
• Standards and Safety of Photobiomodulation Devices