One benefit of light therapy for acne is the ability of blue light therapy to reduce the colonization of Propionibacterium acnes (P. Acnes) in the follicle, thereby reducing the incidence of acne.² In these cases, consistent and frequent use of blue light therapy will be more efficacious in controlling bacterial growth and improving acne. While the sources of light therapy for acne found in professional skin treatments may be stronger, at-home devices used consistently may mimic or even exceed the effects of a single professional light therapy for acne treatment. When choosing an at-home blue light therapy device look for a model that emits wavelengths of 405-420nm. Although manufacturer guidelines for use may differ based on different outputs of energy, most devices will recommend close skin exposure to the light for 5-20 minutes once or twice daily.

There is quite a bit of confusion around the question of blue light therapy causing hyperpigmentation. Studies do show a correlation between blue light therapy and increased hyperpigmentation in Fitzpatrick levels III and higher. For patients with darker skin tones, light therapy for acne in the range of blue visible light may not be the best choice. However, red LED has not been found to induce pigmentation and the calming effect of red LED is also helpful in ameliorating acneic conditions.

Light therapy for acne is cumulative and continued and consistent use will prove more effective in controlling bacterial growth, which is the main function of blue light therapy. In general light therapies such as blue light therapy may take 4-6 weeks to demonstrate a clinical improvement. Not all acne is responsive to blue light therapy, however, and for patients with a rarer gram negative bacterial strain, blue light therapy for acne may have little effect. A professional treatment with light therapy for acne will be more effective than using an at-home model and an experienced skincare professional can provide reasonable expectations for blue light therapy for a particular patient’s condition.³ Since every acne case is unique and not all cases of acne will be responsive to the effect of blue light therapy, it’s best to consult with a trusted skincare professional to choose the appropriate treatment options.

Red LED light has been found to act upon fibroblasts, leading to increased collagen production, whereas blue light therapy is more applicable to acneic conditions wherein it is active in inhibiting P. acnes, a key bacterial player in acne formation. However, because red LED has an anti-inflammatory action in the skin, it is often alternated with blue light in light therapy for acne.

Blue light therapy using LEDs, as is the most common for the treatment room as well as at-home devices, does not impair the skin on it’s own. When used in conjunction with a photosensitizing agent, as is the case in photodynamic therapy, very specific care is needed for the skin. However, when using LED alone as light therapy for acne, it’s important to thoroughly cleanse the skin before exposure to the blue light therapy. This ensures the even and efficacious penetration of the light energy into the skin. Lightweight and non-opaque serums or masks may be applied in conjunction with blue light therapy to keep the skin from feeling uncomfortably dry.⁴

If using blue light therapy as a light therapy for acne, it may be beneficial to follow the blue light therapy with a chemical exfoliator suited to acne such as salicylic, mandelic, azelaic or polyhydroxy acid. If the skin is too sensitive for an exfoliating acid, opt for a soothing serum with calming ingredients. Although marketing for acneic conditions often focuses solely on the bacterial component of acne, in fact the central, and perhaps most visible aspect of acne is inflammation. Look for products containing calming ingredients such as green tea, chamomile, allantoin, centella asiatica, arbutin and niacinamide to calm skin and help prevent post-inflammatory hyperpigmentation. Or if the skin allows, apply a chemical exfoliant, wait 2 minutes for absorption and follow up with a calming serum to complete a blue light therapy treatment. If possible, consult with a trusted skincare professional to create an appropriate at-home skincare treatment plan.