What studies have investigated the effects of low-level laser therapy (LLLT) or photobiomodulation (PBM) using red light on skin?

From the Guidelines

Red light therapy, specifically low-level laser therapy (LLLT) or photobiomodulation (PBM), has been investigated for its effects on skin conditions, including acne, with the most recent and highest quality study suggesting its efficacy in reducing inflammation and sebum production 1.

Studies on Red Light Therapy for Skin Conditions

Several studies have examined the use of red light therapy for various skin conditions, including acne, actinic keratosis, and psoriasis.

• A study published in 2021 found that ALA-red light PDT was effective in reducing actinic keratosis lesions, with a complete clearance rate of 74% after 12 months 1.
• Another study published in 2019 discussed the use of red light therapy for acne, noting that it can reduce inflammation and sebum production, although the quality of evidence is low to support its efficacy 1.
• A 2008 study found that ALA-PDT using red light was effective in reducing inflammatory acne lesions, with a significant reduction in lesion counts after three weekly treatments 1.

Mechanism of Action

The mechanism of action of red light therapy involves the penetration of red light into skin layers, stimulating cellular energy production in mitochondria, increasing ATP production, boosting collagen synthesis, reducing inflammation, and improving circulation.

• This leads to improvements in skin texture, wrinkles, and collagen production, as well as reduced inflammation and accelerated tissue repair.

Treatment Protocols

Treatment protocols for red light therapy typically involve 2-3 sessions per week for 4-12 weeks, with each session lasting 10-20 minutes.

• The use of red light therapy, often combined with blue light, has been shown to be effective in reducing inflammation and sebum production in acne patients.

Safety and Efficacy

Most studies report minimal side effects, making red light therapy generally safe for most skin types.

• However, results vary between individuals, and consistent use is typically required for optimal outcomes.
• The 2021 study found that ALA-daylight PDT was equally effective as ALA-red light PDT, but with less pain, making it a potentially preferable treatment option for some patients 1.

From the Research

Studies Investigating Low-Level Laser Therapy (LLLT) or Photobiomodulation (PBM) Using Red Light on Skin

• The study 2 investigated the effects of low-level red plus near infrared lights combination on collagen and elastin production in human skin in vitro, finding that it stimulated the production of collagen and elastin associated with anti-ageing benefits.
• The study 3 compared the efficacy and side effects of red light and blue light therapies for mild-to-moderate acne vulgaris, finding that red light and blue light therapies have similar efficacy, but red light had advantages with fewer adverse reactions.
• The study 4 evaluated the use of blue light and a mixed blue and red light in the treatment of acne vulgaris, finding that phototherapy with mixed blue-red light was an effective means of treating acne vulgaris of mild to moderate severity.
• The study 5 explored the effects of light treatment of different wavelengths for acne, finding that there is low certainty of the usefulness of methyl aminolevulinate (MAL)-PDT (activated by red light) or aminolevulinic acid (ALA)-PDT (activated by blue light) as standard therapies for people with moderate to severe acne.
• The study 6 assessed the efficacy of red light phototherapy alone in acne vulgaris, finding that red light phototherapy alone can be a new therapeutic option for acne vulgaris, with significant improvement in noninflammatory and inflammatory lesion counts and a decrease in visual analog scale (VAS) scores.

Key Findings

• Low-level red plus near infrared lights combination can stimulate collagen and elastin production in human skin in vitro 2.
• Red light therapy can be an effective treatment for mild-to-moderate acne vulgaris, with fewer adverse reactions compared to blue light therapy 3.
• Mixed blue-red light phototherapy can be an effective means of treating acne vulgaris of mild to moderate severity 4.
• Red light phototherapy alone can be a therapeutic option for acne vulgaris, with significant improvement in lesion counts and VAS scores 6.

Treatment Outcomes

• Improvement in collagen and elastin production 2.
• Reduction in acne lesions and improvement in skin appearance 3, 4, 6.
• Decrease in visual analog scale (VAS) scores 6.

Comparison of Light Therapies

• Red light therapy vs. blue light therapy: similar efficacy, but red light had advantages with fewer adverse reactions 3.
• Mixed blue-red light phototherapy vs. blue light or red light alone: more effective for treating acne vulgaris 4.
• Red light phototherapy alone vs. control: significant improvement in lesion counts and VAS scores 6.