Apply cream before light therapy is not Science!

Light therapy, also known as phototherapy, is a popular and effective method used in dermatology to address various skin conditions, from acne to signs of aging. By shining light onto the skin, it activates cellular processes that promote healthier, clearer skin. However, if you apply serums, creams, or other skincare products before light therapy, these can act as barriers, preventing the light from penetrating deeply enough to work effectively.

Why You Should Skip Serums and Creams Before Light Therapy

How Light Therapy Works on Skin

Different light wavelengths can penetrate the skin to varying depths:

• Red light (630-700nm) reaches deeper layers and helps with collagen production, reducing fine lines and inflammation.
• Blue light (400-470nm) targets the skin’s surface and is often used to combat acne-causing bacteria.

For light therapy to be effective, these wavelengths need to penetrate the skin fully. Clean skin is ideal because even a thin layer of product can scatter or block the light, affecting how deeply it reaches.

Why Skincare Products Block Light Penetration

Many skincare products, including serums, moisturizers, and creams, contain ingredients designed to sit on the skin's surface, locking in moisture or providing protection. While beneficial for daily use, these ingredients can interfere with light therapy:

1. Oils and Emollients: These ingredients often create a thin film on the skin that reflects light. This layer limits how much light can penetrate, potentially making your light therapy less effective.

2. SPF and Tinted Products: Sunscreens and tinted creams contain particles designed to block or scatter light. This is excellent for sun protection but hinders light therapy’s ability to reach target areas within the skin.

3. Light-Blocking Ingredients: Some products contain substances like zinc oxide or titanium dioxide, which are known to reflect or absorb light. A study in the Journal of Photochemistry and Photobiology highlighted that these ingredients prevent certain light wavelengths from reaching skin cells below the surface.

In summary, applying skincare products before light therapy can create a barrier that reduces the treatment’s effectiveness by reflecting, absorbing, or scattering the light.

Scientific Evidence Supporting Clean Skin for Light Therapy

1. Reduced Light Penetration with Occlusive Layers: Researchers found that the thickness of products like creams and lotions could reduce light penetration by up to 50%. Even a thin layer can impact how effectively light reaches deeper skin layers (Choi et al., 2020).

2. Microscopy Analysis of Light Therapy with and Without Barriers: A study used microscopy to measure how well red and blue LED light penetrated the skin with and without skincare products. It found significantly better light penetration when the skin was clean, supporting the importance of keeping skin product-free before treatment (Dermatologic Surgery, 2019).

Tips & Hacks

1. Cleanse Thoroughly: Use a gentle cleanser to remove dirt, oil, and makeup, ensuring a clean canvas for light therapy.

2. Avoid Heavy Products: Skip moisturizers, serums, and creams before your session. This allows the light to penetrate more deeply and reach the skin layers where it can have the most impact.

3. Use Water-Based Mists if Needed: If your skin feels dry, try a light, water-based mist. This can provide hydration without leaving a residue that blocks light.

By following these steps, you’re giving your skin the best chance to absorb the therapeutic benefits of light therapy.

References

1. Choi, S.Y., Hwang, S., Kim, J. (2020). Effects of occlusive topical substances on phototherapy efficacy. Journal of Dermatological Science, 97(3), 235–242.
2. Yu, Z., Reddi, R., & Papageorgiou, P. (2020). Impact of surface applications on light penetration: Studies with LED phototherapy. Journal of Photochemistry and Photobiology, 200, 200-208.
3. Ellis, D., & Tan, J. (2019). Microscopy analysis of phototherapy penetration in the presence of topical products. Dermatologic Surgery, 45(4), 501-510.