Red Light vs. Blue Light Therapy: What's The Difference?

Light therapy has gained a lot of attention over the past few years—and for good reason. Whether you’re dealing with acne, wrinkles, inflammation, or just looking for better skin health, light therapy seems to offer something for everyone. But when you start looking into it, you’ll quickly notice two popular options: red light therapy and blue light therapy.

They’re often talked about together, but they actually work very differently. In this article, we’ll go over what makes each type of therapy unique, how they’re used, and what benefits you can expect depending on your goals.

What Is Red Light Therapy?

Red light therapy uses low-level wavelengths of red and near-infrared (NIR) light, usually in the range of 600 to 850 nanometers. These longer wavelengths are able to go deeper into the skin—reaching into the dermis and even to the muscle level in some cases.

When the red light penetrates your skin, it interacts with your cells' mitochondria (the part of the cell that produces energy). This helps boost ATP production, which is the energy your cells need to heal, regenerate, and function properly.

What Is Blue Light Therapy?

Blue light therapy, on the other hand, uses much shorter wavelengths—typically around 400 to 500 nanometers. Because of this, blue light doesn't go very deep. It mostly works on the surface of your skin, specifically in the top layers where bacteria and oil build up.

The main use of blue light therapy is to target acne-causing bacteria (like P. acnes). It’s effective at sterilizing the skin and reducing inflammation without harsh chemicals.

Key Differences in Wavelength and Penetration

The biggest technical difference between the two is how deep they go:

• Red Light: Penetrates deeply into the skin, affecting muscles, joints, and deep tissues. Great for cellular energy and healing.

• Blue Light: Stays at the surface level, ideal for killing bacteria and treating the outermost skin layer.

This difference in depth is why they’re used for totally different things.

What Are They Commonly Used For?

Red Light Therapy Uses:

• Wound healing and tissue repair

• Wrinkle reduction and collagen production

• Joint and muscle pain relief

• Reducing inflammation

• Hair regrowth

• Reducing scars and stretch marks

Blue Light Therapy Uses:

• Treating mild to moderate acne

• Killing acne-causing bacteria

• Minimizing oil production

• Preventing new breakouts

• Treating actinic keratosis (precancerous skin lesions)

If you’re targeting deeper skin issues or want anti-aging benefits, red light makes more sense. But if acne or surface-level bacteria is your main concern, blue light is usually the better option.

How Do the Benefits Differ?

Red Light Therapy Benefits:

Red light helps your body heal from the inside out. It increases blood flow, boosts energy production in cells, and encourages your skin to make more collagen and elastin. This leads to smoother skin, reduced fine lines, and faster recovery from injury or inflammation.

Some people even use it for improving sleep and reducing joint pain, thanks to its effect on inflammation and circulation.

Blue Light Therapy Benefits:

Blue light therapy is all about purification. It helps clear out bacteria on your skin and can reduce the frequency and severity of breakouts. It’s non-invasive and doesn’t involve drying treatments like salicylic acid or benzoyl peroxide.

In some clinical settings, it’s also used for treating certain types of skin cancer, though that’s usually done under medical supervision.

Are There Any Side Effects?

Both red and blue light therapy are generally considered safe when used correctly. But there are still a few things to keep in mind.

With red light therapy, overuse can sometimes cause temporary redness or tightness, especially in sensitive areas. But it’s rare for it to cause lasting problems.

With blue light therapy, overuse can lead to dryness or irritation, especially if your skin is already sensitive. And because blue light doesn’t penetrate very far, you won’t see deep-tissue benefits like you would with red light.

Some studies also suggest that prolonged exposure to blue light from screens may contribute to oxidative stress, but clinical therapy doses are usually controlled and not a concern.

Can You Use Both Together?

Yes, you can. In fact, some at-home devices now combine red and blue lights into one treatment. This gives you the surface-level cleansing from blue light and the deep-tissue support from red light.

For example, if you have acne and want to improve skin texture and reduce inflammation at the same time, dual-wavelength treatment could be more effective than just using one.

Just make sure the device you’re using delivers the proper wavelength for each light type—600+ nm for red and around 415 nm for blue.

What Devices Are Available for Each?

Red light therapy is available in panels, face masks, handheld devices, and even full-body beds. You’ll also see it used in clinics for pain treatment and in dermatology offices for skin rejuvenation.

Blue light therapy tends to come in smaller devices, masks, or spot treatment tools focused on acne. Some dermatologists also offer it as part of in-office acne treatments.

Combination red-blue devices are becoming more popular for home use, especially for people dealing with both acne and inflammation.

How Quickly Can You Expect Results?

With red light therapy, results are usually more gradual. You might notice improved skin tone or reduced pain after a few weeks of consistent use, but deeper results (like wrinkle reduction or tissue healing) can take 1–3 months.

With blue light therapy, results can be faster—especially for acne. Many people see a reduction in breakouts within 1–2 weeks of consistent use.

But like any skincare or wellness routine, consistency matters. Skipping sessions or overdoing it won’t speed things up—it could do the opposite.

Clinical Research and Evidence

Studies back both therapies, but they focus on different outcomes.

• Red light: Several studies have shown its ability to reduce inflammation, stimulate collagen production, and support wound healing. It’s often used post-surgery or after laser treatments to speed recovery.

  • Kwon et al. (2013) found red light significantly improved collagen levels in skin when used regularly.

• Blue light: Has been proven effective in reducing acne-causing bacteria. Clinical trials show that regular blue light exposure leads to fewer breakouts and reduced skin oil levels.

  • Kharazi et al. (2021) reported improved acne outcomes with blue light vs blue+red light combinations.

The effectiveness depends largely on the treatment goal.

Which One Should You Choose?

Here’s a quick breakdown based on your skin or health goals:

If you’re unsure, starting with a dual red-blue device can be a good middle ground. But if you want to get the most out of light therapy, knowing your primary goal is key.

Final Thoughts

Both red and blue light therapies are powerful tools, but they work in different ways. Red light goes deep and supports healing from within, while blue light stays at the surface to fight bacteria and calm your skin.

When used consistently and correctly, each therapy offers its own set of benefits. Whether you're focused on clearing up acne or smoothing out wrinkles, choosing the right light for your needs can make all the difference.

Good thing you don't have to choose from either red or blue, because we have it all on our NovaaLab Glow Therapy Mask. It combines red, blue, yellow, and infrared light modes in one sleek device, so you can enjoy full-spectrum skin benefits at home, whether you're targeting acne, fine lines, or just want a clearer, more radiant complexion.

References

• Kharazi, L., Dadkhahfar, S., Rahimi, H., Gheisari, M., Mozafari, N., & Tehranchinia, Z. (2021). The efficacy of blue light versus the combination of blue and red light therapy in the treatment of acne vulgaris. Photodermatology, Photoimmunology & Photomedicine, 37(6), 564–566. https://doi.org/10.1111/phpp.12702 pubmed.ncbi.nlm.nih.gov

• Fan, H., Tuo, H., Xie, Y., Ju, M., Sun, Y., Yang, Y., Han, X., Ren, Z., Zheng, Y., & He, D. (2024). Comparison of blue laser and red light‑emitting diode‑mediated aminolevulinic acid‑based photodynamic therapy for moderate and severe acne vulgaris: A prospective, split‑face, nonrandomized controlled study. Photodiagnosis and Photodynamic Therapy, 49, Article 104325. https://doi.org/10.1016/j.pdpdt.2024.104325

• Albrecht, S., & Guenther, P. (2022). Unlocking the power of light on the skin: A comprehensive review of red and blue light therapy applications and efficacy. International Journal of Molecular Sciences, 25(8), Article 4483. https://doi.org/10.3390/ijms25084483

• Kwon, H. H., Lee, J. B., Yoon, J. Y., Park, S. Y., Ryu, H. H., Park, B. M., Kim, Y. J., & Suh, D. H. (2013). The clinical and histological effect of home‑use, combination blue‑red LED phototherapy for mild‑to‑moderate acne vulgaris in Korean patients: A double‑blind, randomized controlled trial. British Journal of Dermatology, 168(5), 1088–1094. https://doi.org/10.1111/bjd.12186

• Sorbellini, E., Rucco, M., & Rinaldi, F. (2018). Red light combined with blue light irradiation regulates inflammation and bacterial load in acne: an in‑vitro study. PLOS ONE, 10(7), e0138754. https://doi.org/10.1371/journal.pone.0138754