Are There Side Effects to Red Light Therapy?
Red light therapy is one of the fastest-growing fields of study, and an exciting treatment that has numerous beneficial effects on the human body. It is used to treat skin disorders, muscle fatigue, hair loss, and joint pain, as well as neurodegenerative brain disorders and chronic inflammation, among other conditions.
As with any type of treatment, however, people want to be assured of red light therapy’s safety—especially in light of the risks, side effects, and negative interactions of many drugs and other types of remedies. In this article we will explore the question on many people’s minds before they use red light therapy: Is it safe? Any red light therapy side effects they should know of? And if so, do the benefits outweigh the risks?
Healing with Light
In order to understand what red light therapy is and how it works, it’s important to know some basics about light and how it affects the human body. Sunlight, which is the main source of natural light, causes biological reactions in our bodies. The sleep-wake cycle (known as circadian rhythm), moods, and even how well our immune systems function are all directly linked to sunlight.
Since ancient times, sunlight has been used for healing. But through the years scientists have learned that too much sunlight can be harmful. Its powerful ultraviolet rays can cause sunburn, premature aging of the skin, and increased risk of skin cancer, as well as eye damage if someone looks directly at the sun.
Although we see rays of sunlight as white, it is actually all colors mixed together, which collectively appear to be white. In fact, rainbows are light from the sun separated into its separate colors: red, orange, yellow, green, blue, indigo, and violet. Each of these colors has a different wavelength, with red the longest and blue the shortest. Wavelengths are typically measured in nanometers (nm).
Based on extensive research, scientists know a great deal about the health benefits of specific wavelengths of light. Green, blue, yellow, and red wavelengths have all been used successfully to treat specific conditions. Of all commonly used light therapies, red and near-infrared (NIR) wavelengths have the broadest range of therapeutic benefits.
What Is Red Light Therapy
The term “red light therapy,” which is also referred to as low-level laser therapy (LLLT) or photobiomodulation, encompasses light therapy in the red (630nm to 660nm) and near-infrared (810nm to 850nm) range. Red light devices use light-emitting diode (LED) bulbs to deliver specific wavelengths of light in powerful concentrations that absorb into the skin and have therapeutic benefits at the cellular level.
Red light, and particularly near-infrared (NIR) wavelengths, penetrate deep into the body where they have a stimulating effect on cells. Light photons absorb into the mitochondria, which are colloquially known as the “power generators” of cells. As mitochondria soak up the light, this increases production of cellular fuel known as adenosine triphosphate (ATP). The cells become energized, making them better able to perform their functions, and repair and regenerate themselves more efficiently.
Increased cellular energy causes a positive chain reaction that boosts overall health throughout your body.
Increased cellular energy has a positive ripple effect throughout the entire body. It’s similar to how your energy levels affect your ability to perform at your peak (or your worst) at work, to handle obstacles, to cope with adversity, to maintain healthy relationships, and still have the energy to take care of yourself.
The process by which low-level laser therapy positively impacts health at the cellular level has been scientifically proven. Some of the fascinating benefits of red/NIR therapy include:
- Anti-aging: Regular use reduces fine lines, sagging skin, sun damage, and wrinkles by stimulating collagen and elastin production, reducing inflammation, and stimulating blood flow.
- Hair regrowth: Red light supports the regrowth of hair when light photons energize dormant hair follicles. It also helps treat underlying conditions such as hypothyroidism, which can contribute to non-hereditary hair loss.
- Osteoarthritis pain: Red light reduces inflammation to ease joint pain and restore mobility due to
- Chronic skin disorders: Red light in the 620nm to 660nm range, and NIR light in the 810nm to 850nm range, effectively treat acne, psoriasis, non-melanoma skin cancers, rosacea, and other skin conditions by reducing inflammation and promoting healthy collagen production.
- Physical performance: Red and NIR light wavelengths help maximize athletic performance and speed up healing of muscle damage due to intense exercise or injury.
- Low back pain: Near-infrared light supports healthy muscle and connective tissue growth and reduces inflammation to ease chronic low back pain.
- Weight loss: Red light therapy can help with fat loss and helps with spot-treatment of fat, since it causes fat cells to develop tiny fissures that allow lipids to leak out. It also increases the thickness and suppleness of skin, which helps reduce the appearance of cellulite.
It’s important to note that although red and near-infrared wavelengths absorb into the body at different depths, this doesn’t necessarily mean that one is better than the other; it means they are complementary. In general, the shorter wavelengths (630nm to 660nm) are used to treat skin-deep conditions, whereas the longer wavelengths (810nm to 850nm) are used to treat conditions deeper in the body. For optimal results, both should be used simultaneously.
This is just a sampling of the incredible benefits of red light therapy. Given the current body of research, light therapy is not considered a cure for any condition. However, since the light in the red/NIR ranges has the greatest range of benefits of any wavelengths (according to thousands of studies), they fall into what’s called the "therapeutic window" of light energy. Red and NIR light promote energy production at the cellular level, the ripple effect of healthy cells may have the potential to eliminate the underlying causes of many chronic conditions. Rather than focusing just on relieving the symptoms, light therapy helps to address the root causes.
What Does Science Say About Red Light Therapy Safety?
Thousands of peer-reviewed studies have been conducted on red light therapy, and none have found any safety issues either short-term or long-term use, to label red light therapy dangerous. Studies that included follow-ups showed no adverse effects after prolonged use of light therapy LED devices. Here are few examples:
- A five-year study of patients with age-related macular degeneration, which was published in 2018, found that LLLT is an effective treatment for the condition, and results in long-term improved vision with no side effects.
- Red light therapy is known to stimulate healthy, normal skin cell proliferation in wound healing. But when the patient has a malignant tumor, health care practitioners often hesitate to recommend the treatment for fear of promoting tumor growth. According to a 2011 study, however, red light therapy was safe even in the presence of malignant lesions, and did not contribute to their growth.
- 9 clinical studies demonstrate that subjects exposed to red/NIR light experienced skin rejuvenation with no side effects.
- Fluctuating hormones may cause pregnant women to develop acne. Unlike oral tetracycline, which has been associated with miscarriages, red light therapy has been found to be effective in treating acne and safe for use during pregnancy.
- In a 1992 study, elderly patients with degenerative osteoarthritis in the knee were treated with red light therapy. It reduced their pain by 50% over the control group, and significantly improved range of motion and strength, with no side effects.
- In a four-week rheumatoid arthritis study, 112 volunteers received red light therapy treatments to reduce pain from rheumatoid arthritis, with remarkable results: a 70% reduction in pain, significant reduction of morning stiffness, and increased tip to palm flexibility. No side effects were observed or reported.
Is Red Light Therapy Safe?
There is no research or evidence showing that red light is harmful.
Some light wavelengths, such as UVA and UVB , are harmful to your body, but red and NIR light are actually beneficial for a wide range of health and wellness applications.
When evaluating red light therapy’s effects, it’s important not to confuse it with ultraviolet (UVA and UVB) phototherapy, because treatment involving UV wavelengths does carry risks. As with excessive sunlight, UV exposure can lead to premature aging, skin cancer, and eye damage.
Conversely, in studies that focused exclusively on the visible light spectrum (630 nm to 660nm and 810nm to 850nm), no side effects were observed during clinical trials, nor were any reported afterward.
Since few studies have examined red light therapy for longer than a few months (one eye study took place over five years) and because the therapy was only popularized in the early 2000s , potential long-term effects of red light therapy remain unknown. The lack of both red light and infrared light therapy side effects over the short term may indicate that adverse reactions are unlikely as long as the LED device is used as directed.
Most chronic skin disorders require one to four months of consistent treatment, and no studies have cautioned against long-term treatment. A few have taken a more conservative stance, stating that more research may be needed; but no adverse consequences have been observed during or immediately after treatment.
The only exception to this strong safety record is individuals with highly photo-sensitive skin, and people taking medications that amplify their photosensitivity. For this reason, it's important to seek medical advice before treating your skin while taking any medications (some do not overtly state that they have photo-sensitizing effects).
For people with cancer, LLLT should only be used on the advice of a medical professional. The therapy is not associated with the onset of cancer, but its use may be contraindicated in certain types of cancers, and it is not recommended for use during chemotherapy treatments.
How Often Should You Use Red Light Therapy?
First, it’s always advisable to seek medical advice before attempting to treat a health condition using LED light therapy at home. For example, if you are treating what you believe to be minor sun damage, you want to make sure you’re not actually dealing with a serious condition such as skin cancer.
Always use the LED light therapy device as directed. This means maintaining the correct distance from the device, and starting slowly with shorter sessions to determine your level of sensitivity. Most commonly, you’ll enjoy a relaxing red light session three to five times per week for 10 to 20 minutes at a time, over a period of one to four months.
When used as directed, red light therapy is safe. Therapy sessions are painless, and free from side effects. Individuals with highly sensitive skin may experience temporary redness and tightness after treating with red light, but this can often be managed by shortening the sessions, reducing the number of weekly treatments, and/or moving farther back from the device.
If you feel uncertain about long-term use of a red light therapy device, one approach you can take is to use the device only until your symptoms abate, and then take a break. Keep in mind that chronic skin conditions such as rosacea or eczema may require a consistent maintenance treatment protocol, so you need to weigh the benefits (reduced or eliminated symptoms) against the possibility of side effects (even though none have ever been found).
In small doses, red light is considered a safe therapy for improving eye health. Eye fatigue may occur after too much exposure to red light, so wear protective goggles while treating other parts of the body. The therapy time needed to treat the skin is much longer than the time needed for treatment of the eyes.
Choosing the Right LED Therapy Device
Different types of red light devices are available, from handheld wands and masks to tablet-sized panels to huge multi-panel units. This makes the choices somewhat overwhelming! Here’s what to look for.
You will get the most benefits and highest return on your investment by choosing an LED panel that irradiates a larger portion of the body, which will activate a positive ripple effect of increased cellular health.
The initial investment in a high-quality red light therapy device easily pays for itself if you are considering using red light to treat even one or two conditions, such as improving skin tone and reducing signs of aging. This is because many people who start using red light for these purposes often experience benefits they didn’t expect. Red light therapy is also effective for treating hair loss, skin wounds, stretch marks, and promoting muscle repair and weight loss.
The more of your body's cells that are energized using red light therapy, the better. Choose the largest panel that fits into your budget, so that you can target small areas while still improving your all-over health.
Red Light Therapy Side Effects & Numerous Health Benefits: Minimal to No Risk
Given the often severe side effects of many drugs and medications, red light therapy is a much better choice. It is a natural, safe, and effective method to experience relief from symptoms, and even healing.
To read more about the uses of red light, its innumerable benefits, and the many studies that have been conducted, be sure to visit the PlatinumLED blog.
Frequently Asked Questions
Are all light therapy side effects the same?
Ans: With differing properties, some side effects may prove to be common, but not all.
Do the benefits of using red light therapy outweigh the dangers?
Ans: Although there hasn't been enough research to verify the long term repercussions (if any), but so far, the short term efficacy of light therapy seems to carry its weight