Standard red light therapy is not known to cause cancer. It uses low-energy red or near-infrared light, not ultraviolet (UV) radiation, which can damage DNA and cause skin cancer. The American Academy of Dermatology says research has not found red light therapy to cause cancer.
Two questions often get mixed together: whether red light therapy can cause a new cancer, and whether it is safe to use over an existing or suspicious tumor. The available evidence gives different levels of certainty for each question. Evidence reviewed here should be checked against ****.
Red Light Therapy and Cancer Risk at a Glance
| Question | Evidence-based answer |
|---|---|
| Can ordinary red light therapy cause new cancer? | No evidence currently shows that it does. |
| Is red light the same as UV light from tanning beds? | No. UV light can damage DNA and cause skin cancer. Red light therapy uses a different part of the light spectrum. |
| Can red light therapy safely treat an existing tumor? | Do not assume so. Avoid direct treatment over a tumor without medical guidance. |
| Can cancer survivors use red light therapy? | They may be able to, but they should discuss it with a clinician, especially near the previous cancer site. |
| Is photodynamic therapy the same as red light therapy? | No. Photodynamic therapy combines light with a photosensitizing drug to destroy cancer cells. |
Why Is Red Light Therapy Different From UV Radiation?
Red light therapy uses visible red light and, in some devices, near-infrared light. These wavelengths are non-ionizing and differ from ultraviolet radiation, X-rays and radioactive radiation.
UV radiation is strongly linked with DNA damage, premature skin aging and skin cancer. Red light therapy is intended to produce biological effects without significantly heating or burning the skin.
Side effects can include temporary redness, warmth, irritation, pigmentation changes and burns if a device is misused. Eye injury is also possible. Follow the manufacturer's instructions about eye protection.
Can Red Light Therapy Make Existing Cancer Grow?
There is no clear clinical evidence that standard red light therapy causes cancer recurrence or makes cancer spread. A systematic review of photobiomodulation and cancer-treatment side effects found no tumor-safety problems in the available clinical literature. A separate review of red and near-infrared light for cosmetic skin rejuvenation found no relevant clinical-trial evidence linking treatment with a new or recurrent malignancy.
The research has limits. Laboratory and animal studies have produced mixed results, and the effect can depend on the wavelength, intensity, dose, treatment duration and type of cancer cell. Medical cancer centers therefore use defined protocols and avoid directing treatment near tumors when safety has not been established.
Should You Use Red Light Therapy Over a Tumor or Suspicious Skin Lesion?
No. Do not use it there without medical approval.
Avoid using a home red light panel, mask or handheld device directly over:
- A known tumor
- A suspicious, changing or bleeding mole
- Skin cancer or suspected skin cancer
- An unexplained lump or lesion
- An area undergoing cancer treatment
Memorial Sloan Kettering Cancer Center advises against applying photobiomodulation near tumors because its effects on tumors have not been studied sufficiently. The FDA also lists skin cancer or a history of cancer at the treatment site as a reason for caution with certain low-level light therapy devices.
Do not use red light therapy to delay an examination. A dermatologist should assess a changing mole, a sore that does not heal, unexplained bleeding or a new growth.
Can You Use Red Light Therapy After Cancer Treatment?
For some cancer survivors, red light therapy may be considered away from the original tumor site. The decision depends on the cancer type, treatment history and area being treated.
Photobiomodulation is used in some cancer-care settings to manage side effects such as oral mucositis, radiation fibrosis, wounds and certain treatment-related skin problems. Medical providers use defined treatment parameters and decide whether the light should be kept away from tumors.
Ask your oncologist before using red light therapy if you:
- Currently have cancer
- Are receiving chemotherapy, radiation or immunotherapy
- Have had cancer at or near the treatment area
- Have a suspicious skin lesion
- Take a photosensitizing medication
- Have a photosensitivity disorder
- Are pregnant or planning pregnancy
Is Photodynamic Therapy the Same as Red Light Therapy?
No. Photodynamic therapy is a different medical treatment. It uses a photosensitizing drug that accumulates in abnormal cells. A specific light activates the drug, producing a chemical reaction that can destroy cancer cells.
Ordinary consumer red light therapy does not use this drug and should not be considered a cancer treatment.
How Can You Reduce Risks With a Home Device?
Use a home device more safely by:
- Choosing a device intended for the specific use instead of relying on unsupported cancer claims.
- Following the stated exposure time and treatment distance.
- Wearing eye protection when the manufacturer or clinician recommends it.
- Avoiding treatment over tumors, suspicious lesions or recently biopsied areas without medical advice.
- Checking medication warnings for photosensitivity.
- Stopping if you develop persistent pain, blistering, severe redness or visual symptoms.
- Seeking medical evaluation for any suspicious skin change instead of treating it at home.
Bottom Line
If you have active cancer, a previous cancer near the treatment area or a suspicious lesion, ask your oncologist or dermatologist before using red light therapy there. A consumer device is not a cancer treatment and should not replace an examination.