Laser therapy—also called low-level laser therapy (LLLT) or photobiomodulation (PBM)—uses gentle light (usually red or near-infrared wavelengths) to help heal tissues, reduce pain, or improve function. Unlike laser surgery or high-power lasers, LLLT doesn’t cut or burn—it stimulates cells in a mild, non-invasive way. People often ask whether LLLT is safe, effective for conditions like nerve pain, scars, and swelling—and whether it might even cause harm like boosting cancer risk. Here's what current science tells us.
1. Can laser therapy cause cancer?
Have some positive effects, but No. low-level laser therapy isn’t known to cause cancer.
Studies on cultured tumor cells show mixed effects depending on light settings—some tests saw increased growth, others saw decreased growth. However, when used clinically for people—including cancer patients—it’s very safe: a systematic review of 27 studies reported no tumor-promoting effects when used to treat oral mucositis or swelling after cancer treatment.
LLLT works in the 600–1,000 nm range, which doesn’t carry enough energy to damage DNA like UV or X-ray light does. It’s safe within proper doses and under professional guidance. So far, there’s no evidence it causes cancer in real-world medical use.
Reference: Silva JL, et al., Lasers Med Sci. 2020;19 Jun.
Effects of low level laser therapy in cancer cells-a systematic review of the literature - PubMed
2. Can laser therapy help neuropathy?
Yes—especially for diabetic peripheral neuropathy, laser therapy appears to help.
A 2024 systematic review of eight studies showed that PBM significantly reduced neuropathic pain, improved nerve conduction, and even reduced plantar pressure—helping prevent ulcers in diabetes.
Another review in 2019 confirmed favorable effects on neuropathic pain control. There are also promising lab and animal studies showing reduced nerve pain and protective regeneration in injury models. Overall, LLLT is a safe, non-invasive option that may help relieve neuropathy symptoms—though protocols vary, and more standardized research would be helpful.
Reference: Effectiveness of Photobiomodulation Therapy on Neuropathic Pain, Nerve Conduction and Plantar Pressure Distribution in Diabetic Peripheral Neuropathy - A Systematic Review - PubMed
3. Can laser therapy remove scars?
Laser treatment can soften and improve scars, though results depend on laser type and scar type.
In dermatology and plastic surgery, lasers like CO₂ and Nd:YAG are used to resurface skin and remodel scar tissue, helping with surgical scars, burns, and keloids. They stimulate collagen, reduce thick scar tissue, and help the skin look smoother.
These procedures are often medical-grade (higher intensity) and done by dermatologists. Laser treatment is widely used for scar revision—but for best outcomes, multiple sessions and professional evaluation are recommended.
Reference: Laser medicine - Wikipedia
4. Can laser therapy make pain worse?
It’s very uncommon, but pain can temporarily increase if used inappropriately.
Generally, LLLT has anti-inflammatory and pain-relieving effects with no serious side effects in most clinical studies. However, improper settings—like too much intensity or overly frequent treatments—can lead to mild burns, temporary pain, or local irritation.
Following proper guidelines and having treatments done by trained professionals keeps the risk of harm very low.
Reference: Efficacy of low-level light therapy for treatment of diabetic foot ulcer: A systematic review and meta-analysis of randomized controlled trials - PubMed
5. Can laser therapy help rotator cuff tear?
Possibly—but evidence is still limited and mixed.
LLLT can reduce pain and swelling in tendinopathies like tennis elbow and plantar fasciitis, and there's evidence it helps with shoulder tendon issues. But rotator cuff tears—involving actual tearing of shoulder tendons—are more complex.
While LLLT might ease pain or support inflammation control, it’s not a replacement for physical therapy or surgery. Some studies on general shoulder tendinopathy show benefit, but specific trials on rotator cuff tears are few.
Reference: Low-level laser therapy - Wikipedia
6. Can laser therapy help rosacea?
Yes—laser treatments are widely used to reduce redness and visible blood vessels in rosacea.
While LLLT isn't the main laser used for rosacea, vascular lasers (like PDL, IPL) are effective in treating rosacea symptoms such as persistent redness and visible veins. They target blood vessels specifically and are standard dermatology tools.
Gentler LLLT may reduce inflammation, but for visible redness or broken vessels, vascular lasers or IPL are better supported.
Reference: Rosacea: New Concepts in Classification and Treatment - PubMed
7. Can laser therapy help nerve damage?
Yes—there is promising evidence that laser therapy may support nerve healing after injury.
Animal and lab studies show that PBM can stimulate the regeneration of nerve fibers, support rebuilding of the myelin sheath (the nerve’s protective coating), and reduce inflammation after nerve injury.
In humans, most studies focus on neuropathic symptoms rather than structural healing. But clinical improvements in nerve function—like improved conduction and reduced symptoms—suggest true nerve support in conditions like diabetic neuropathy.
Reference: Clinical application of low-level laser therapy (Photo-biomodulation therapy) in the management of breast cancer-related lymphedema: a systematic review | BMC Cancer | Full Text
