Red Light Therapy (RLT)

Red light therapy (sometimes called LED therapy) is a form of photobiomodulation (PBM) that refers to therapies that use visible red light light to stimulate the skin cells in a beneficial way. Most at-home RLT devices use multiple LED's of varying (and often undocumented) power, that produce light at a wavelength of 630 to 660 nanometres. This light penetrates approximately 2 millimetre into the skin, stimulating collagen production and promoting connective tissue repair and regeneration. Around 80% of our skin (excluding water and other liquids) is connective tissue, of which collagen is the main protein structure. Thus, RLT can improve and/or speed the repair of damaged skin and help reverse the natural decline in collagen production and corresponding decline in skin quality seen as we age.

As it's a non-invasive treatment with minimal side-effects this therapy is becoming increasingly popular for a range of medical and cosmetic issues such as wound healing, scar reduction, wrinkle reduction and facial rejuvenation as detailed in the following sections.

Warning

Those with skin of colour should discuss any treatment with a medical professional as most studies have been performed on those with white skin. Darker skin may absorb more light which may lead to undesirable effects or make treatment ineffective. In these cases, radio frequency therapy may be preferable.

Benefits

While these benefits may be evidenced by scientific research; domestic, at-home appliances may not have the same power or features as those used in the studies referenced or those found in a professional medical setting. Additionally, be careful to adhere to the instructions provided with the device and use it consistently at the recommended frequency.

Skin Appearance

RLT Can improve the skin's appearance through;

increasing blood flow/circulation
increasing collagen and growth factor production ¹
promoting connective tissue repair and regeneration
possible stem cell activation

You can also take a collagen supplement to attempt to counteract the natural decline in collagen production seen as we age. However, there's no evidence any collagen you consume would be used in the skin.

Applying retinol to the skin can also increase collagen production and promote connective tissue repair and regeneration.

You could also use radio frequency therapy to tighten your skin and increase collagen production.

Hair

This has been well known for some time.⁵ ⁶ ⁷

Just RLT will do but NIR also helps.

830nm at least, most products have 630/660nm and 830nm wavelengths which is good.

Sleep

Wound Healing & Scarring

Unproven.

Burn Healing

At Home Devices

watts per sqm matters (i.e power/light output) - outputs ranging from 40mW/cm² to 100mW/cm²

Skin colour (and reflectivity) also has an impact

Burdens

Forms/Types

When to Avoid Use - Interactions/Contraindications

Frequency, Timing & Duration

Typically once or twice a day for 20 minutes.

Protocols

Recovery

Further Information

photobiomodulation therapies should be safe for those who've previously had cancer⁸

Light Wavelengths

Light encompasses a number of different wavelengths, each with different properties, some visible, some not.

Designation	Abbreviation	Wavelength	Visible	Uses
Ultraviolet	UV	10–400 nm	No
Blue light		450-495 nm	Yes	Skin
Red light		625–750 nm	Yes	Skin, hair
Near-infrared	NIR	0.78–3 μm/780-3k nm	No	Skin, hair
Mid-infrared	MIR	3–50 μm/3k-50k nm	No
Far-infrared	FIR	50–1,000 μm/50k-1m nm	No	Sauna