Red light therapy involves exposing the skin and body to strong sources of visible red light (610-700nm).
As a natural, non-invasive method there are a wide variety of applications, not to mention a wide variety of sources.
It is most commonly used to treat skin conditions, and it does so well, but there are a whole host of further potential benefits.
The beauty of this type of treatment is that there are no known side effects, yet a long and well studied list of benefits.
It is a perfectly safe way to promote skin healing, energy production and youthful metabolism all over the body.
How it works
Red light interacts with the body in a similar way to infrared light – This involves a few mechanisms including by increasing energy (ATP) generation on the cellular level.
The key difference between red and infrared is that red wavelengths of light are absorbed and used in the first 25mm of skin tissue, whereas infrared light can penetrate much deeper into the body.
This same mechanism is also responsible for many of the benefits of sunlight, which contains the red wavelengths as part of its spectrum. Sunlight however, comes bundled with harmful UV & blue light, making red light therapy superior in some respects.
Most red light devices on the market are weak and will only penetrate 2 – 3mm of skin tissue. Stronger devices such as 100w+ LED light devices can reach through the entire skin layer, healing from the bottom up.
The Wavelengths of Red Light Therapy
Red light therapy uses any wavelength between 610 nm and 700 nm.
The most common wavelengths you will see are 630 nm (orange-red) and 660 nm (deep red) which roughly coincide with the absorption peaks of cytochrome c oxidase (the target of light therapy), plus they are cheaply available and efficient. While effective, these are not necessarily the perfectly optimal wavelengths.
The absolute optimal spectrum ranges are 610-625nm & 660-690nm.
The absolute optimal single wavelengths are 620nm and 680nm.
These optimal wavelengths vary to some degree in different studies and different cells. 615nm and 670nm are also sometimes optimal.
What specifically does it do in the cell?
Visible red light from a good high powered source and in the right intensity can penetrate skin by up to 25mm. There are a variety of cellular structures that absorb light energy including the mitochondria:
- Our mitochondria can absorb red light due to a key energy producing copper enzyme (cytochrome c oxidase – link) which absorbs light at various wavelengths between 600-1000nm.
- Metabolism in the mitochondria is usually restricted by a biologically active molecule called nitric oxide, which binds to cytochrome oxidase and prevents it from using oxygen. Red light acts by photodissociating (or detaching) this nitric oxide molecule, allowing cytochrome to resume its energy producing metabolic function.
- Red light has been shown to improve the structure of water in cellular cytoplasm and other areas of the body, providing a functional benefit to all cellular processes. The improved surface tension of cells may also improve ion exchange.
- Through a complex but well understood process, cytochrome helps to synthesise ATP
- Red light increases ROS (reactive oxygen species) which have a positive stimulatory effect in low amounts.
The net effect of the above mechisms is as follows:
- Increased energy levels.
- Reduced local/systemic inflammation
- Faster and better wound healing
- Lower likelihood of scars
- Protects against excess oestrogen
- Reduces cortisol stress hormone levels
- Protects against radiation
- Activates formation of new cells for healing
- Increased growth of new mitochondria
- Improved blood flow / circulation
- Increased lymph flow.
- Increased repair of skin including collagen.
All of the above go some way to explaining the benefit you will get from red light therapy, whether it be for anti-aging, wound healing or treating a skin condition.
Who does it benefit?
Red light therapy is entirely safe and non-invasive, meaning it can be used by anyone – young or old.
It works on a foundational level of the body, meaning everyone benefits to some extent.
However the most benefit comes to those without regular skin exposure to sunlight, or those with skin conditions and signs of aging.
Can red light therapy be used for beauty?
Red light therapy improves the appearance of the skin on a number of levels.
- Reduces wrinkles & fine lines
- Treats hair loss
- Treats skin conditions such as eczema and acne
- Promotes speedy healing of wounds
- Reverses signs of sun damage
- Limits and reverses general signs of aging
What is the standard treatment like?
The light is simply applied for a short amount of time (5 – 15 minutes), after which further therapy would show quickly diminishing returns.
This is known as a biphasic dose response – lower doses give a good effect, very high doses a negative (or neutral) effect. The reason why longer session times gives diminshing returns is not very well understood, possibly involving ROS or nitric oxide release.
Regardless, a short therapy session gives better results than constant use for hours on end.
How often can it be used?
The red light would ideally be applied 3-4 days per week and continue like that for 4-6 weeks.
For general maintenance and health once or twice a week is acceptable.
Are there any risks from red light therapy?
There are a wide range of benefits from red light therapy, but what about the risks?
- There are no serious side effects.
- Staring directly into the light for extended periods is not advisable for obvious reasons.
- Using high dose infrared on sensitive ‘man parts’ for extended periods could cause discomfort
LED, incandescent, heat lamp, etc. Which light source is best?
There are a wide variety of devices capable of outputting beneficial wavelengths of red light, including; LED, lasers, incandescent, halogen, low level laser, fluorescent, etc.
All sources of red light will have their advantages and disadvantages, but all will be capable of producing some level of beneficial effect.
The reasons why red LED devices stand out from the rest include:
- The most energy efficient
- Most lumens per watt
- Less energy wasted as heat
- The longest lasting (50000 hours)
- More specific wavelengths available