Red Light Therapy for Warts & Skin Tags

Warts and skin tags are among the most common benign skin growths. Warts are caused by human papillomavirus (HPV) infection, whilst skin tags (acrochordons) are harmless fibrous outgrowths typically found in skin folds. Both are medically benign but cosmetically bothersome, and both have been the subject of claims about red light therapy’s potential benefits.

This page examines the evidence honestly. The conclusion — stated upfront — is that red light therapy alone has very limited evidence for treating either condition. However, the related field of photodynamic therapy (PDT), which combines specific light wavelengths with photosensitising agents, is a well-established treatment for warts.

Warts: how they form and persist

Warts are caused by HPV infection of keratinocytes in the epidermis. Over 200 HPV subtypes exist, with subtypes 1, 2, 4, 27, and 57 being the most common causes of cutaneous warts.

The virus enters through breaks in the skin and hijacks the cell’s replication machinery, causing rapid proliferation of infected keratinocytes. This produces the characteristic raised, rough-surfaced lesion. The virus simultaneously evades the immune system through several mechanisms:

• Downregulation of antigen presentation — HPV reduces the expression of major histocompatibility complex (MHC) class I molecules on infected cells, making them less visible to cytotoxic T cells
• Inhibition of interferon signalling — HPV proteins (particularly E6 and E7) block interferon-mediated antiviral responses
• Minimal inflammation — Unlike many viral infections, HPV replicates without causing cell lysis, producing little inflammatory response to alert the immune system

This immune evasion is why warts can persist for months or years. When the immune system eventually recognises and targets the infection, warts resolve spontaneously — which happens in approximately 65 per cent of cases within two years.

Standard treatments include cryotherapy (liquid nitrogen), salicylic acid, curettage, and for recalcitrant warts, immunotherapy or photodynamic therapy.

Red light therapy alone for warts — the evidence

There is no published clinical evidence that red light therapy (photobiomodulation with 630 to 850nm wavelengths without a photosensitiser) effectively treats warts. No randomised controlled trials, no case series, and no mechanistic studies specifically demonstrate that low-level red or near-infrared light can eliminate HPV-infected tissue.

Why red light therapy alone is unlikely to work

The problem is straightforward: red light therapy’s primary mechanisms — mitochondrial stimulation, anti-inflammatory effects, and tissue repair — do not address the root cause of warts, which is a viral infection that the immune system has failed to recognise.

• Mitochondrial stimulation would enhance the metabolism of both healthy cells and HPV-infected cells. It would not selectively target infected keratinocytes.
• Anti-inflammatory effects are irrelevant because warts are characterised by minimal inflammation. If anything, more inflammation around the wart would be beneficial, as it could alert the immune system to the viral infection.
• Tissue repair mechanisms (increased collagen, fibroblast proliferation) would not address the underlying viral cause.

The one theoretical pathway that could be relevant is immune modulation. Red light therapy has been shown to enhance immune cell activity, including natural killer cells and T lymphocytes. If photobiomodulation could strengthen the local immune response enough to overcome HPV’s immune evasion, it could theoretically contribute to wart clearance. However, this remains entirely speculative for warts — no study has demonstrated this effect in practice.

Photodynamic therapy for warts — a different approach

Photodynamic therapy (PDT) is fundamentally different from red light therapy, and it is important not to confuse the two.

PDT involves three components:

1. A photosensitising agent — Most commonly aminolevulinic acid (ALA) or methyl aminolevulinate (MAL), applied topically to the wart
2. Light activation — Typically red light at 630 to 635nm, which activates the photosensitiser
3. Oxygen — The activated photosensitiser generates reactive oxygen species that destroy the targeted cells

The photosensitiser accumulates preferentially in rapidly dividing cells — which HPV-infected keratinocytes are. When activated by light, it generates singlet oxygen that destroys these cells selectively.

Fehr et al. (1995) and subsequent studies have demonstrated that ALA-PDT achieves clearance rates of 56 to 100 per cent for various types of warts, depending on the study, wart type, and number of treatment sessions (Dermatology, 190(3), 192-196). A systematic review by Defined et al. (2016) confirmed that PDT is effective for recalcitrant warts that have failed conventional treatments.

Key distinction: PDT uses red light as an activation mechanism for a photosensitising drug. The light alone would not produce the same effect. Standard red light therapy devices do not include photosensitising agents and cannot replicate PDT results.

PDT is a clinical procedure performed by dermatologists. It is not something you can replicate at home with a consumer red light therapy device.

Skin tags: the evidence

Skin tags are benign fibroepithelial polyps — small, soft, pedunculated (stalk-attached) growths that typically develop in areas of skin friction: the neck, armpits, groin folds, and under the breasts. They are associated with obesity, insulin resistance, and ageing, and affect approximately 46 per cent of the general population.

Red light therapy for skin tags

There is no published clinical evidence that red light therapy removes or shrinks skin tags.

Skin tags are composed of a fibrovascular core covered by a thin epidermis. They are not inflammatory, not infectious, and not caused by cellular dysfunction that photobiomodulation would address. They are essentially excess tissue, and removing them requires physical destruction of that tissue — which low-level light therapy is not designed to do.

Standard skin tag removal methods include:

• Snip excision — Cutting the stalk with scissors (simple, effective, minimal scarring)
• Cryotherapy — Freezing with liquid nitrogen
• Electrocautery — Burning the stalk with a heated probe
• Ligation — Tying off the blood supply with thread or a commercial device

These methods work because they physically destroy or remove the tissue. Red light therapy, by design, is non-destructive — it promotes cellular health rather than ablating tissue.

When might red light therapy play a supporting role?

Whilst red light therapy is not effective as a primary treatment for either warts or skin tags, it could potentially support recovery after conventional treatment:

Post-cryotherapy healing. After liquid nitrogen treatment for warts, the treatment site often forms a blister and takes one to three weeks to heal. Red light therapy at 660nm could accelerate wound healing and reduce inflammation at the treatment site, potentially improving cosmetic outcomes.

Post-excision scarring. After surgical removal of warts or skin tags, red light therapy could promote collagen remodelling and reduce scar formation. Barolet and Boucher (2010) demonstrated that 660nm LED therapy improved the appearance of surgical scars (Journal of Cosmetic and Laser Therapy, 12(2), 66-69).

Immune support. For patients with recurrent or widespread warts — suggesting a systemic immune deficit in recognising HPV — the immunomodulatory effects of whole-body red light therapy could theoretically complement targeted wart treatments. This is speculative but biologically plausible.

What about online claims?

A search for “red light therapy for warts” returns numerous blog posts and product pages claiming that red light devices can clear warts. These claims are not supported by clinical evidence. In many cases, the sources confuse photodynamic therapy (which does work) with standard photobiomodulation (which does not work for this application).

Be cautious of anecdotal reports. Warts resolve spontaneously in the majority of cases. A person who starts using red light therapy and sees their wart disappear three months later may attribute the result to the therapy when it was natural immune clearance.

The bottom line

Red light therapy alone is not an effective treatment for warts or skin tags based on current evidence. The mechanisms of photobiomodulation — mitochondrial stimulation, anti-inflammatory effects, tissue repair — do not address the underlying causes of either condition.

Photodynamic therapy (PDT), which uses red light to activate a photosensitising drug applied to warts, is effective — but this is a fundamentally different procedure performed by dermatologists, not something achievable with a consumer device.

If you have persistent warts, see a dermatologist or GP. If you have skin tags that bother you, simple excision or cryotherapy is fast, inexpensive, and effective.

Red light therapy has genuine applications for many skin conditions. Warts and skin tags are not among them — at least not based on the evidence available today.