Red light therapy appears generally well tolerated in the short term, but it is not risk-free. The American Academy of Dermatology (AAD) reports that mild pain or skin irritation can occur and that long-term effects on skin and hair are not fully known.
Common Minor Side Effects
Discomfort or irritated skin can occur. Do not assume pain, persistent redness, or a headache means the treatment is working or your body is adapting. Stop treatment if it causes symptoms and seek clinical advice if they persist. The AAD also warns that visible light may worsen hyperpigmentation in some people with darker skin tones.
Overexposure Effects (Biphasic Dose Response)
More exposure is not necessarily more effective. There is no universal safe session length or distance for every device. Follow the manufacturer's directions, including limits on frequency and eye protection. Do not copy another device's schedule or move closer to increase the dose.
Red and near-infrared light are not ultraviolet light. The AAD reports that research has not found red light to cause cancer, while also noting uncertainty about long-term effects. This is not proof of zero risk under every exposure condition or permission to treat a suspicious lesion yourself.
Who should consult a clinician first?
- Light-sensitive conditions or medications: The AAD recommends checking whether treatment could worsen a condition such as lupus or interact with a light-sensitizing medication. Ask your prescriber or pharmacist about your exact medicine and device.
- Pigmentation concerns: Ask a dermatologist, especially if visible light has previously worsened dark spots.
- Cancer, a suspicious lesion, pregnancy, an eye condition, or other ongoing medical care: Seek individualized advice rather than treating this general guide as clearance to use a device.
What safety claims should you distrust?
Be cautious of claims such as "no side effects," "safe with all medications," or "cannot damage eyes or skin." A light treatment can still be inappropriate for a person taking an oral medication that increases light sensitivity. Review our eye-safety guide and use the protective equipment specified for your device.