Red light therapy (RLT) is a controversial therapeutic technique that uses red low-level wavelengths of light to treat skin issues, such as wrinkles, scars, and persistent wounds, among other conditions.
In the early 1990s, RLT was used by scientists to help grow plants in space. The scientists found that the intense light from red light-emitting diodes (LEDs) helped promote growth and photosynthesis of plant cells.
Red light was then studied for its potential application in medicine, more specifically to find out if RLT could increase energy inside human cells. The researchers hoped that RLT could be an effective way to treat the muscle atrophy, slow wound healing, and bone density issues caused by weightlessness during space travel.
You may have heard of red light therapy (RLT) by its other names, which include:
low level light therapy (LLLT)
soft laser therapy
cold laser therapy
low-power laser therapy (LPLT)
When RLT is used with photosensitizing medications, it’s referred to as photodynamic therapy. In this type of therapy, the light only serves as an activating agent for the medication.
There are many different types of red light therapy. Red light beds found at salons are said to help reduce cosmetic skin issues, like stretch marks and wrinkles. Red light therapy used in an medical office setting may be used to treat more serious conditions, like psoriasis, slow-healing wounds, and even the side effects of chemotherapy.
While there’s a fair amount of evidence to show that RLT may be a promising treatment for certain conditions, there’s still a lot to learn about how it works, too.
Red Light Therapy vs. Blue Light Therapy: What’s The Difference?
Blue and red light therapies, two forms of phototherapy, have some similar benefits and uses, although they work in different ways. The mechanism of action of both is still not entirely well-understood, but it’s believed that LLLT devices produce light with wavelengths similar to those of blue light lasers only with broader output peaks (they’re less monochromatic and don’t produce heat or friction).
Blue light is more commonly used at home from light-emitting devices, especially for the treatment of acne. It’s been found that blue light reaches the sebaceous (oil) glands in the skin and can help kill porphyrins, which are compounds inside acne bacteria. (12)
Red light is believed to penetrate the skin deeper and may also help acne and other skin disorders by reducing inflammation and improving healing.
Blue light and red light can be emitted from tabletop light therapy devices (which are used at home and usually weaker, requiring about a total of 30 minutes to one hour of treatment time twice per day) or from stronger devices used in doctors’ offices that work quicker (sometimes within just several minutes or less).
The Wellman Center for Photomedicine at Massachusetts General Hospital explains that there’s still widespread uncertainty and confusion surrounding the mechanisms of action of these light therapies, especially LLLT, at the molecular, cellular and tissue levels. There are also a large number of parameters for doctors to consider before treating individual patients (wavelength, fluence, irradiance, treatment timing and repetition, pulsing, and polarization) that can add to the confusion and patient variability in terms of results. (13)
Types of Red Light Therapy?
There are a few different ways that you can treat yourself with red light therapy. Some salons offer a tanning bed-style red light therapy machine, which looks very similar to a sunbed. However, the red light therapy beds do not release dangerous ultraviolet (UV) radiation as sunbeds do.
The most convenient way to treat yourself with red light therapy though is at home. Many kits can be bought for home use. Some kits are designed for use specifically on the face and come in the form of a facial mask, while others are hand-held devices that you hold onto your body, and others are larger screens that can treat larger areas such as the back or chest.
Another way that red light therapy can differ is the actual light used. Often nowadays, LEDs are used, but low-energy lasers can also be used. The light produced can vary between machines, with different wavelengths being emitted, such as infrared light. Different wavelengths can affect different symptoms differently, so it is good to find out which wavelength is best suited to treat your condition.
Is Red Light Therapy Safe?
Red light therapy uses visible light in the form of lasers or LED. It cannot affect DNA so cannot cause cells to mutate or cause cancer. Red light therapy is generally tolerated very well, although results will vary between people and some conditions will respond better than others.
Red Light Therapy Side Effects
It is thought that red light therapy has virtually no side effects and those which may occur will be mild and will not last long. For example, eye strain or a headache may be caused by the glare of the intense light. Take care not to stare directly into the light to prevent this and wear suitable eye protection. Some red light therapy kits have built-in eye protection.
Care should also be taken when considering the dose being given. Lower doses can be more effective than higher doses. Some effects such as mild nausea or dizziness and muscle weakness may be attributed to overuse, so care should be taken when considering how long a light therapy session will last. Overuse, particularly by infra-red sources, can cause burns so care should be taken to prevent overexposing your skin. If you do suffer a burn, treat it as you would sunburn, keeping it clean to prevent infection and keeping it moisturized.
The skin may be more sensitive to sunlight after red light therapy, so take care to always wear adequate sun protection.
What Is Red Light Therapy Used For?
Red Light Therapy Acne
Red light therapy can soothe acne because it can improve circulation and inflammation through the energy transfer. This means that painful, swollen spots may be reduced in size and the lymphatic system can more efficiently clear away waste products, which could prevent the build-up of spot-causing products within the skin. It is also thought that it can shrink oil glands and therefore reduce the amount of oil which is produced.
Red light can also be used in conjunction with blue light to treat acne. While the red light is reducing the visual effects of acne by decreasing swelling and pain, the blue light can kill certain types of spot-causing bacteria such as Propionibacterium acnes. When used together, the two types of light therapy can, therefore, reduce and prevent future breakouts.
A key factor in treating acne with red light therapy facials is that lower doses are the most effective. It is not beneficial to dry your skin out, but a “little and often” treatment plan will give you the best results. While this may take you a while to see the benefits, it is worthwhile in the long run.
A final consideration for treating acne with red light therapy is its effect on scars. You may find that superficial acne scars soften in appearance, becoming less noticeable. Using red light therapy to treat acne may also reduce the rate at which scars occur. This is thought to be partly due to the enhanced collagen and elastin production and partly due to the improved circulation which can promote good healing.
Red Light Therapy For Weight Loss
Red light therapy can aid weight loss due to the way it increases the rate at which mitochondria produce energy, as well as the increase in circulation. The energy currency in the body which all cells require to be able to function is called adenosine triphosphate (ATP). Organelles in the cells, called mitochondria, convert glucose by a complicated process into ATP which can be used to fuel cells. If the mitochondrial function is enhanced by the red light, more glucose will be converted, which could aid weight loss.
The improved circulation can help with weight loss as it will increase the rate at which waste products are removed from the body. However, it is important to understand that red light therapy alone will not cause to you lose a great amount of weight. For best results, it should be combined with regular exercise and a healthy diet.
Red Light Therapy For Frozen Shoulder
A review by Page et al. concluded that both low-level laser therapy (LLLT) alone and LLLT used in conjunction with exercise was more effective at easing symptoms of adhesive capsulitis, also known as frozen shoulder, than the study placebo. This was a fantastic step forward in the management of frozen shoulders, which are notoriously difficult to treat.
Red Light Therapy For Restless Leg Syndrome
A study by Mitchel et al. in 2011 found that red light therapy using near-infrared light for the treatment of restless leg syndrome (RLS) saw significant improvements in symptoms. Out of a total of 34 volunteers, the study group has much greater improvement that the control group did, with results still significantly improved 4 weeks after the treatment period ended. This was a valuable breakthrough which could see patients with RLS being treated with red light therapy instead of dopamine-affecting drugs in the future.
Red Light Therapy For Wound Healing
Many studies have shown that red light therapy is an effective therapy for the treatment of skin wounds, as discussed in a review in 2014. A reduction in inflammatory cells, increase in the formation of new blood vessels, known as angiogenesis and an increase in collagen productions are among the biological effects noted which are thought to enable to enhanced wound healing. This review also noted that there didn’t seem to be a difference between results from studies which used lasers for the delivery of the light or whether it was from LEDs.
Benefits of Red Light Therapy?
The main benefits of red light therapy are thought to have come from the energy exchange. The responses of cells and tissues to red light therapy, which does not itself produce much heat, can be comparable to the body’s reaction to heat. Certain wavelengths of red light can penetrate beyond the skin’s surface, where it is absorbed into the cells deeper than other wavelengths of visible light can. This deeper-reaching light can have the following benefits:
Reduce Joint Stiffness
Applying heat to a joint can reduce stiffness by as much as 20%, and effects of red light therapy are thought to be similar. This can have a cyclical pain-reduction result as less stiffness and associated pain can encourage you to use a joint more, which can reduce further stiffness.
Relieves Muscle Spasms
Muscle spasms can cause pain because they can restrict the blood flow to certain areas of the body, which can cause cells and tissues to be starved of oxygen. Applying red light can result in the muscles relaxing which will allow better circulation of the area. This means that conditions such as restless leg syndrome can be very responsive to red light therapy.
Improves Blood Flow
Just like the body’s natural response to heat is to dilate blood vessels, it does the same when exposed to red light. This widening of blood vessels reduces resistance to the blood flow, therefore improving the rate at which it can move around the body.
This is a great benefit because the restriction of blood flow can cause cells to be starved of oxygen. Lack of oxygen, which is called ischemia can permanently damage tissues, particularly in the muscles as it can kill cells, some of which cannot be replaced.
The improved blood flow and lymphatic circulation aid the removal of waste products from the lymphatic system. This reduces and prevents the build-up of fluids which can cause edema, therefore reducing pain associated with swelling and can even enhance the healing mechanisms.
Aids Pain Relief
The reduction in pain relief can come from a combination of the above effects on tissues. Joint stiffness, muscle spasms, restricted blood flow and inflammation can all cause and contribute to pain. By reducing those symptoms, red light therapy can, therefore, reduce pain.
Improves Elasticity of Collagen Fibers
Red light therapy at certain wavelengths is thought to stimulate the productions of collagen and elastin fibers, as well as the creation of new capillaries. A greater number of capillaries within the skin will improve blood flow to the skin tissues and therefore the transportation of oxygen and nutrients to the cells, while the extra collagen and elastin will smooth and plump-out the skin. This can slow and reduce the effects of aging on the skin, giving a more youthful appearance.