Red light therapy is not known to cause cancer based on current evidence. Two facts explain why: red and near-infrared light used in photobiomodulation are non-ionising, unlike ultraviolet radiation and X-rays, which can damage DNA and raise cancer risk. A 2025 expert consensus found that red-light photobiomodulation does not cause DNA damage in adults.
Long-term research on some home-use devices is still limited. Do not use red light therapy over a suspicious lesion, active skin cancer or a cancer treatment site without medical advice.
At a Glance
| Question | Answer |
|---|---|
| Does red light therapy cause cancer? | Current evidence does not show that it causes cancer. |
| Is red light the same as UV light? | No. Red light is visible, non-ionising light. UV light can cause skin cancer. |
| Can red light therapy be used over a mole or suspicious lesion? | No. Have the area assessed by a dermatologist first. |
| Can people with cancer use photobiomodulation? | Sometimes, but only with guidance from the treating oncology team. |
| Is "FDA-cleared" the same as proven effective? | No. FDA clearance relates to a device's regulatory pathway and safety classification. It does not guarantee a particular result. |
Why Red Light Therapy Is Not Considered Carcinogenic
Red light therapy, also called photobiomodulation, uses low-intensity red or near-infrared light from LEDs or low-level lasers. These devices are designed to produce little or no heat and do not use ultraviolet radiation.
The American Academy of Dermatology says that research has not found red light to cause cancer. A 2025 expert consensus also concluded that red-light photobiomodulation does not induce DNA damage in adults.
The evidence is not equally extensive for every device. Red light masks, panels, hair-growth helmets and clinical equipment can differ in wavelength, power, treatment time, distance from the skin and frequency of use.
Can Red Light Therapy Make an Existing Cancer Grow?
Laboratory studies have produced mixed findings. Results vary according to the cancer cell type and the light settings used.
Clinical and animal evidence reviewed to date has not shown that photobiomodulation increases tumour growth or cancer recurrence when used with recommended clinical protocols.
A 2023 systematic review of photobiomodulation for cosmetic skin rejuvenation found no relevant clinical trial evidence linking the treatment to a new or recurrent malignancy. It also found no evidence that everyone previously treated for cancer must avoid red light therapy.
People with active cancer, a suspicious skin growth or a history of cancer at the proposed treatment site should still speak with a healthcare professional first. The U.S. Food and Drug Administration lists skin cancer or a history of cancer at the treatment site as a reason to avoid certain photobiomodulation body-contouring procedures.
Is Red Light Therapy Safe During Cancer Treatment?
Oncology teams sometimes use photobiomodulation to help manage treatment side effects, including oral mucositis, radiation-related skin reactions, lymphoedema and nerve symptoms. Systematic reviews have not identified a tumour-safety problem with recommended clinical protocols.
A consumer red light mask or panel is different. Chemotherapy, radiotherapy, immunotherapy and surgery can affect skin sensitivity, healing, medication interactions and infection risk. Ask the oncologist or radiation specialist managing your treatment before using a home device.
Red Light Therapy Is Not the Same as Photodynamic Therapy
These treatments use light in different ways:
- Red light therapy or photobiomodulation uses low-level red or near-infrared light without a cancer-targeting drug.
- Photodynamic therapy uses a photosensitising drug that becomes active when exposed to a particular wavelength of light. The activated drug can destroy cancer cells.
Photodynamic therapy is an established treatment for some cancers and precancers. Its use does not mean that ordinary red light therapy causes cancer.
What Are the Main Risks of Home Red Light Devices?
Cancer is not the main known risk of properly used red light therapy. More practical risks include:
- Eye injury from looking directly at bright LEDs or ignoring protective eyewear.
- Burns or skin irritation caused by excessive exposure or a faulty device.
- Temporary redness, pain or sensitivity.
- Darkening of pigmentation, particularly in some people with darker skin tones.
- Worsening of light-sensitive conditions such as lupus.
- Reactions caused by photosensitising medicines.
To reduce these risks, use a device designed for the intended treatment, follow its exposure instructions and wear the recommended eye protection.
"FDA-cleared" indicates that a device has met a regulatory pathway associated with low risk. It does not prove that the device will deliver a particular cosmetic or medical result.
When Should You Avoid Red Light Therapy Until You Get Medical Advice?
Speak with a healthcare professional before using red light therapy if you:
- Have a new, changing, bleeding or non-healing skin lesion.
- Have active skin cancer or cancer at the proposed treatment site.
- Have previously had cancer at that site.
- Are receiving chemotherapy, radiotherapy or another cancer treatment.
- Take medication that increases sensitivity to light.
- Have lupus or another photosensitivity disorder.
- Need to treat an area near the eyes.
Bottom Line
Red light therapy has not been shown to cause cancer, and current evidence does not indicate that properly used photobiomodulation promotes cancer in humans. Do not shine it over an undiagnosed lesion or active cancer. If you have cancer, a cancer history or take photosensitising medication, get advice from your dermatologist or oncology team first.