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Evidence Based

This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of licensed nutritionists and dietitians strive to be objective, unbiased, honest and to present both sides of the argument.

This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

What’s True and What’s Hype? Red Light Therapy Pros and Cons

Written by Dr. Ruscio on November 25, 2022

Written by Dr. Ruscio on November 25, 2022 — Reviewed by Hannah Hamlin

Dr. Michael Ruscio is a DC, Naturopathic Practitioner, researcher, and clinician. He serves as an Adjunct Professor at the University of Bridgeport and has published numerous papers in scientific journals as well as the book Healthy Gut, Healthy You. He also founded the Ruscio Institute of Functional Health, where he helps patients with a wide range of GI conditions and serves as the Head of Research.

• What is Red Light Therapy and How Does it Work?|
• Red Light Therapy Pros|
• Red Light Therapy Cons|
• RLT Pros and Cons: Will You Try It?|

If you’ve been seeing red light therapy (RLT), especially at-home systems, in ads on your favorite social network platform, you’re not alone. 

This type of therapy is growing in popularity because it’s a non-invasive way to address cosmetic issues as well as reduce pain for certain musculoskeletal and neurological conditions. RLT has a number of applications that have been shown to be safe and effective in clinical trials, which I’ll elaborate on below. 

If you’re dealing with skin conditions or are looking for a non-surgical anti-aging treatment, RLT might be a great place to start, but it certainly isn’t a miracle cure for aging or weight loss. In addition to some of the cosmetic benefits, it has also been shown to be effective in wound healing and certain categories of body pain [1, 2]. 

But are there risks to this type of treatment? And can it really do everything those ads you’re seeing claim it can? Many of the benefits are still speculative, with unclear protocols and little evidence to back them up. While side effects are minimal and temporary, they do include potential hyperpigmentation and skin sensitivity.

Let’s take a closer look at red light therapy pros and cons to help you get a sense of what this treatment is, which claims are supported by evidence, and which aren’t. By the time you finish reading, you’ll have a much better sense of whether or not this treatment is right for you and your wellness journey.

What is Red Light Therapy, and How Does it Work?

The light appears red in RLT because of wavelengths of light it emits along the visible part (the rainbow) of the electromagnetic radiation spectrum. The wavelength frequency of RLT ranges between 600-1070 nanometers (nm) and differentiates it from its close relative, near-infrared light, which is invisible to the human eye [3]. Unlike RLT, infrared emits heat and is often used in saunas.

Other names for the same treatment include low-level laser therapy (LLLT), low-level light therapy, photobiomodulation, red light phototherapy, and cold laser therapy [3, 4, 5, 6]. They’re all referring to the same intervention, which is simply the temporary exposure to red light to stimulate healing [3].

The precise mechanisms of RLT are still being understood, but we know that the target of effects is at the molecular, cellular, and tissue levels [3]. RLT appears to penetrate skin cells and stimulate mitochondria to produce ATP (adenosine triphosphate), which is the primary energy source your body uses to function. It also [3, 7, 8]: 

• Promotes the release of molecules needed for healing (cytokines, chemokines, and other molecules)
• Increases production and activity of fibroblasts and macrophages (promotes wound healing and better skin health)
• Improves mobility of immune cells
• Promotes collagen and elastin production (benefits skin health)
• Increases blood flow and promotes new blood vessel formation
• Offers anti-inflammatory effects
• Reduces oxidative stress (which is linked to illness and aging)
• Provides antibacterial activity

So it makes sense that dermatologists would want to use it in skin care and wound-healing, while orthopedists might recommend it for osteoarthritis or other musculoskeletal inflammation. Let’s take a further look at the proposed benefits of RLT.

Red Light Therapy Pros

The benefits of red light therapy stretch across a number of fields of medicine, but the uses you’re likely most familiar with are cosmetic. That’s because red light therapy can promote skin health in a number of ways across almost all skin types and tones. 

The home devices you’ve likely seen advertised are often marketed for the more topical/cosmetic uses — anti-aging, body sculpting, etc — however, the potential for RLT reaches further than that.

RLT can help with joint pain relief, nerve pain relief, wound healing, hair loss, and even brain and mental health [1, 9, 10, 11, 12]. It works on the cellular level to reduce inflammation, making it highly beneficial for many areas of your health and wellness. 

Depending on the device you get, you can enjoy these benefits at home, but consult a medical professional before purchasing an at-home device.

Anti-Aging and Contouring

RLT has been shown to improve signs of aging due to its ability to penetrate skin tissue and increase ATP production, blood flow, and promote tissue repair and healing [3, 7, 13]. It also appears to have anti-aging effects on the skin. One systematic review found low-quality evidence that RLT can increase skin rejuvenation and reduce fine lines [1]. 

Individual clinical trials have demonstrated several different effects of RLT on skin, including [14, 15]:

• Lessening the severity of wrinkles
• Improving collagen production and density
• Skin hydration
• Skin elasticity

Despite these benefits, improvements may be considered mild, and the appropriate parameters for RLT are still being investigated [13, 15].

Red light therapy is also used frequently for weight loss and to improve physical shape. One comprehensive review found that it is safe and effective for body contouring and sculpting, likely because it helps to release fat from fat cells [4, 16]. However, the use of RLT to reduce cellulite for cosmetic purposes isn’t supported by the evidence [1].

While RLT does not appear to aid in clinically meaningful weight loss, it does seem to improve body composition [17, 18]. One study found that 20 minutes of RLT every other day for 2 weeks helped remove about an inch from the waist, hips, and thighs of participants [19]. Another study found that RLT led to a combined reduction in the hip, waist, and upper abdomen of over 10 centimeters in obese individuals [17]. 

One study that investigated the effect of RLT on exercise showed that in obese women, RLT combined with exercise led to significantly greater fat loss, improved insulin levels, and less insulin resistance than in the exercise-only group [18, 20].

Overall, it’s unclear if RLT plays a significant role in weight loss, making well-researched, diet and exercise interventions much more attractive options. 

Acne, Rosacea, and Herpes

Since the mechanisms of RLT are still being explored, the quality of evidence supporting its effectiveness on these three skin conditions is a little bit thin. However, some of the results are promising. 

There is moderate quality evidence that RLT can improve acne vulgaris, although one study found that RLT was no more effective than other conventional treatments and other light sources [1, 4, 21].

A 2022 animal study found that RLT significantly improved facial redness and inflammation in a mouse model of rosacea, but the human evidence was a little muddled [22]. 

Another 2020 case report found that a 68-year-old male with rosacea underwent 10 sessions of RLT combined with blue light therapy, and the results showed significant visual improvement in his rosacea [23]. Though promising, this is an isolated, small study that requires more scientific support and a better understanding of both red and blue light effects. 

Additionally, red light therapy helps improve viral infections like herpes zoster which is responsible for painful shingles [1]. Herpes simplex is in the same family and is known for causing oral and genital ulcers, but there’s no evidence to support that RLT helps against these skin issues.

Overall more research and clinical evidence are needed to better understand the role that RLT plays in dermatologic conditions before it can be safely and effectively implemented.

Pain and Wound Healing

RLT has been shown to promote the healing process of topical wounds in animal studies. That’s because it promotes blood flow and improves cell growth [24]. Human studies have also shown improved healing of diabetic foot ulcers, skin rashes caused by cancer radiation therapy, and acute wounds [1, 9, 10]. 

This isn’t to say that RLT is capable of healing all types of wounds, but the available research shows that it’s an effective treatment in these specific areas.

RLT can also improve musculoskeletal pain, including [2, 25, 26, 27, 28, 29]:

• Tendinopathy
• Knee osteoarthritis
• Plantar fasciitis pain
• Chronic, non-specific, low back pain

The most clinically significant improvements in pain were in the cases of plantar fasciitis and lower back pain. However, in many of these studies, the improvements were modest and/or temporary.

In addition to musculoskeletal pain, one meta-analysis found that RLT led to a fairly impactful level of improvement in fibromyalgia pain and stiffness compared to placebo lasers [30].

These results are highly promising for those dealing with chronic pain, and it appears to be effective in the short term. However, the lasting effects of red light therapy aren’t clear. Because the durability of this treatment isn’t known, RLT can be a great add-on for those who are already practicing a healthy lifestyle but probably isn’t a great stand-alone therapy for pain.

Hair Growth Treatment

Red light therapy treatments have been shown to stimulate hair growth in patients with androgenic alopecia (male pattern baldness), but commercial claims exaggerate the level of improvement shown in clinical trials [4, 31, 32]. One study found that there was no difference in patient satisfaction between the RLT group and the control group, suggesting that the regrowth was mild and possibly not noticeable enough [32].

Brain and Mental Health

The research on the effects of red light therapy on Alzheimer’s and Parkinson’s disease is still lacking in quality, however, two systematic reviews found that RLT may have small to moderate beneficial effects on dementia [11, 12]. Another study found that RLT appears to have positive effects on stroke patients, promising news for future study [33].

On the mental health side, red light therapy works to improve depression and anxiety in fibromyalgia patients, according to a systematic review and a smaller study [30, 34]. While this early research is encouraging, all of the researchers in these studies noted the need for larger, higher-quality research to further understand the health benefits of red light therapy devices.

Red Light Therapy Cons

The list of cons of red light therapy is far shorter than the pros, however, it’s important to be aware that there are some potential (and typically short-term) side effects to using RLT. It’s generally considered safe, but some topical risks include [21, 35]:

• Skin irritation 
• Redness 
• Stinging 
• Peeling 
• Hyperpigmentation (darkened spots) 
• Skin ulcers

Of this list, hyperpigmentation may last longest, so if you’ve experienced hyperpigmentation for other reasons and are concerned that your skin is particularly sensitive to that, you might want to test out RLT on an inconspicuous area before using it on your face. It’s probably a good idea to avoid tanning in the sun before using RLT to potentially reduce the risk of hyperpigmentation.

Unsupported Claims and Lack of Evidence

A hidden con of red light therapy is unmet expectations. The hype that advertisers give to this type of therapy can be overblown and get your hopes up for a miracle cure that won’t come. 

Clearly, I’ve listed a number of exciting uses for RLT that are backed by science, but the list isn’t endless, and more work needs to be done across every category I’ve mentioned to better understand the therapeutic mechanisms of RLT. Much of the research on RLT is considered low quality, which means that the results may not be reproducible in the general population [4].

Another major issue of RLT is that the ideal parameters (i.e., the ideal dose, wavelength, frequency, and duration) for treatment have yet to be determined for many health conditions, and there is debate on which source of red light is the best [3]. Additionally, both at-home and in-office devices can be expensive and time-consuming.

Conditions That Don’t Show Benefit

The research strongly suggests that RLT will not improve issues of psoriasis or eczema, despite the benefits it provides for other skin conditions [1]. A 2019 literature review stated that RLT “can not be currently be recommended for the treatment of inflammatory skin diseases because of the lack of well-controlled studies” [36]. 

It may not be an effective treatment for carpal tunnel syndrome, despite the various other uses to reduce inflammation in the musculoskeletal system [37, 38]. And any claims that it can cure cancer or detoxify your body are also bogus.

Though it’s likely that red light therapy can help a number of other health conditions, it is expensive, the protocols are unclear, and the research behind it is mixed. For these reasons, it may not be the best first step in your healing journey. However, it can be an effective adjunctive treatment, once you’ve addressed the underlying cause of your condition, like poor gut health. 

If you’re looking to improve your immunity, skin health, brain health, and mood, there’s more research supporting the benefits of other natural treatments like probiotics, which can be a more accessible and affordable start.

Red Light Therapy Pros and Cons: Will You Try It?

Overall, red light therapy has been studied in the context of anti-aging, body sculpting, pain relief, hair loss, wound healing, and brain health. The available research suggests that it’s a valuable tool in healthcare that can benefit a number of conditions.

However, anyone interested in RLT should be careful to temper their expectations due to the high volume of exaggerated claims that occur in the literature and in the marketplace. It’s also not without minor potential side effects, all of which are topical, and most of which are temporary.

If you want to talk with a medical professional about whether red light therapy is the right choice for you, schedule a time to meet with one of our clinicians. We would love to help.

The Ruscio Institute has developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.