Red light therapy (RLT), or photobiomodulation, shows significant promise in reducing the appearance of certain types of acne scarring, though its efficacy varies depending on the scar depth and age. At wavelengths between 630nm and 660nm, red light penetrates the dermis to stimulate mitochondrial activity in fibroblasts. Scientific evidence suggests this process accelerates the synthesis of new collagen and elastin fibres while modulating the inflammatory response, which can help to level the skin's texture and improve the appearance of shallow atrophic scars [1], [2].
However, it is important to distinguish between different types of scarring. While RLT is highly effective at reducing the lingering redness known as post-inflammatory erythema (PIE) through improved microcirculation and lymphatic drainage, it is less effective as a standalone treatment for deep, structural 'pitted' scars like ice-pick or boxcar scars. In these cases, clinical studies often show that RLT works best as an adjunctive therapy, enhancing the healing response and outcomes when used alongside more invasive procedures like microneedling or fractional laser therapy [3].
The biological mechanism behind red light therapy involves the absorption of photons by cytochrome c oxidase within the mitochondria. This photophysical reaction leads to an increase in Adenosine Triphosphate (ATP) production and a mild, transient increase in reactive oxygen species (ROS), which together trigger various intracellular signalling pathways. In the context of wound healing and scar remodeling, these signals promote fibroblast proliferation and the reorganising of the extracellular matrix (ECM) [4].
Furthermore, RLT modulates the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs). By regulating these enzymes, the therapy prevents the excessive degradation of healthy tissue while encouraging the structured deposition of Type I and Type III collagen. This balanced remodelling is crucial for preventing the formation of hypertrophic scars and gradually filling in depressed areas left by prior inflammatory acne lesions [5].
For those looking to support the skin’s natural recovery process after light therapy, our Surface Purify BHA Cleanser helps to gently manage congestion and clarify the complexion with salicylic acid and bakuchiol. To further assist with evening out the appearance of lingering marks, the Cellular Thread peptide serum was formulated with Gotu Kola and Licorice Root to support skin longevity and luminosity.
FAQ
Does red light therapy help with post-inflammatory hyperpigmentation (PIH)?
Yes, red light therapy can assist with Pigmentation issues, though it is often more effective for redness (erythema) than dark brown spots. By reducing overall inflammation and improving cellular turnover, it helps the skin to shed pigmented cells more efficiently. However, near-infrared (NIR) wavelengths are sometimes better suited for deeper pigment concerns, provided they are used at controlled intensities to avoid heat-induced melanogenesis [2], [6].
How long does it take to see results for acne scars?
Clinical results are rarely instantaneous. Studies typically indicate that consistent treatment—usually 2 to 3 sessions per week for a period of 8 to 12 weeks—is required before significant improvements in skin texture and scar depth become visible. Because collagen synthesis is a slow biological process, the peak results are often observed several months after the initial treatment course concludes [1], [4].
Are at-home red light devices effective for scarring?
At-home devices can be effective, but they generally possess lower irradiance (power output) compared to clinical-grade panels used by dermatologists. While they can maintain results and support the skin's barrier, professional treatments are usually necessary for treating significant acne scarring because they deliver the precise dosage and depth of penetration required to trigger deep dermal remodelling [3], [5].
References:
[1] Wunsch A, Matuschka K. Photomedicine and Laser Surgery. 2014;32(2):93-100. doi:10.1089/pho.2013.3616.
[2] Avci P, et al. Seminars in Cutaneous Medicine and Surgery. 2013;32(1):41-52.
[3] Na JI, et al. Journal of Cosmetic and Laser Therapy. 2017;19(3):141-146. doi:10.1080/14764172.2016.1262341.
[4] Hamblin MR. AIMS Biophysics. 2017;4(3):337-361. doi:10.3934/biophy.2017.3.337.
[5] Barolet D, et al. Journal of Investigative Dermatology. 2009;129(12):2751-2759. doi:10.1038/jid.2009.186.
[6] Jagdeo J, et al. Journal of Drugs in Dermatology. 2018;17(3):284-288.
Medical Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any new skincare regimen. Content reviewed by a biomedical scientist.
