Unfortunately many if not most people have unhealthy skin. The skin comes into contact with a great many toxins. Skin is inactivated by clothing and bathing in very hot water. Most Americans today are relatively sedentary and do not sweat enough. ¹

There are also many diseases and disorders that primarily or secondarily involve the skin. Direct and indirect costs borne by our society related to these skin problems run into the billions of dollars each year.

Low level laser (light) therapy (LLLT), phototherapy or photobiomodulation, all refer to the use of light for altering biological activity of certain target within the human body. ²

An enormous amount of research over the past 10 to 15 years has discovered many beneficial applications of phototherapy in treating a variety of health problems and disorders. ³

LLLT uses either non-ablative low power lasers or non-coherent light sources consisting of filtered lamps such as the tungsten filament heat lamps used in near infrared lamp saunas or light-emitting diodes (LED). The main medical applications of LLLT have been reducing pain and inflammation, augmenting tissue repair and promoting regeneration of different tissues and nerves, and preventing tissue damage.

There are multiple significant variables in terms of dose parameters: wavelength, power density, pulse structure, coherence, energy, irradiation time, contact vs non-contact application, repetition regimen and more. Lower doses can result in reduced effectiveness of the treatment and higher ones can lead to tissue damage.

While treatment protocol uncertainties remain, there is one irrefutable fact of phototherapy. Virtually all LLLT research and medical applications revolve around the use of light in the visible red and near infrared spectrum. This is the same light spectrum emitted by the tungsten filament lamps in near infrared lamp saunas.

The same light is contained in sun light, in fact, over 50% of sunlight that reaches the surface of the earth is near infrared light. ⁴ Tiny receptors in our bodies called chromophores have an optical window that only absorbs and responds to near infrared light. ⁵

Skin starts showing its first signs of aging in the late 20s to early 30s and it usually presents with wrinkles, dyspigmentation, telangiectasia, and loss of elasticity. Common features are reduction in the amount of collagen, fragmentation of collagen fibers, degeneration of elastic fibers, dilated and tortuous dermal vessels, and atrophy and disorientation of the epidermis. The passage of time and environmental influences are responsible for the aging process; however sun exposure seems to be one of the most important causes of these changes.^{6 7}

Several modalities have been developed in order to reverse the dermal and epidermal signs of photo- and chronological aging including are retinoic acid (a vitamin A derivative), dermabrasion, chemical peels, and ablative laser resurfacing. ^{8 9 10} However, these procedures require intensive post-treatment care, prolonged downtime and may lead to complications. ^{11 12} These limitations created a need for the development of alternative rejuvenation procedures that were safer, more effective, with fewer side effects. ¹³

Non-ablative skin rejuvenation aims to improve photoaged and aging skin without destroying the epidermis. LED light sources provide near infrared light for non-thermal, non-ablative skin rejuvenation shown to be effective for improving wrinkles and skin laxity. LLLT promotes collagen and elastin formation as well as wound healing. Phototherapy improves the appearance of aged and photoaged skin in a safe manner. ^{14 15 16 17}

Acne vulgaris is a relatively common skin disorder, with a reported prevalence of up to 90% among adolescents. Although typical acne is neither a serious nor a contagious condition, it can greatly impact the emotional and social aspects of an individual’s life. Current therapies for acne vulgaris include topical antibiotics and other topical compounds. In severe cases oral antibiotics and hormones have been used. ^{18 19}

Sunlight exposure has often been reported to have a significant impact on the treatment of acne, with a high efficacy of up to 70%.²⁰ Several studies have demonstrated the efficacy of red to near infrared (NIR) light (spectral range 630 nm to 1000 nm, and non-thermal power less than 200 mW) for the treatment of acne vulgaris. Red light maybe used alone or in combination with other modalities (in particular, blue light).^{21 22 23 24 25 26}

One of the most common virus infections is caused by herpes simplex virus (HSV). HSV is chronic and lasts one’s entire life. The exposure of the host to physical or emotional stresses such as fever, exposure to UV light, and immune suppression causes virus reactivation eruption of “cold sores”.²⁷ Anti-viral drugs have been only partially effective.

LLLT has been suggested as an alternative to current medications for accelerated healing, reducing symptoms and influencing the length of the recurrence period. ^{28 29 30 31 32}

Vitiligo is an acquired pigmentary disorder characterized by depigmentation of the skin and hair. The underlying mechanism of how the depigmentation occurs is uncertain. Therefore, stimulation of these epidermal and dermal cells may be a possible treatment option. Treatment of vitiligo has generally been unsatisfactory.³³ LLLT has been suggested as an alternative effective treatment option for patients with vitiligo. Phototherapy has been shown to improve pigmentation.^{34 3536}

Hypertrophic scars and keloids are benign skin tumors that usually form following surgery, trauma, or acne and are difficult to eradicate. The use of LLLT as a prophylactic method to alter the wound healing process to avoid or attenuate the formation of hypertrophic scars or keloids has been investigated. Near infrared (NIR) LED therapy has been shown to improve scar formation without adverse effects.^{37 38 39 40 41}

Patients treated with NIR LED showed decreased symptoms of burning, redness, swelling, and peeling after acute sunburn. People that receive laser therapy may suffer devastating burns. LED treated laser burns have demonstrated accelerated healing.^{42 43 44}

More recently LLLT has been considered for treatment of plaque psoriasis. A recent preliminary study showed no adverse side effects and a resolution of psoriasis. The limitation of this study was the small number of patients enrolled, however the results observed encourage future investigations for use of LLLT in treating psoriasis.⁴⁵

The UV range (< 400 nm) exposure is responsible for almost all damaging photo-induced effects on human skin. ^{46 47 48} Existing solutions to prevent UV damage are based on either avoidance of sun exposure or by use of sunscreens. Sun avoidance might be hard to implement, especially for the people involved in outdoor occupations or activities. Topical sunscreens have their own limitations as well.

It has recently been suggested that infrared (IR) exposure might have protective effects against UV-induced skin damage mainly by triggering protective/repair responses to UV irradiation. ^{49 50 51}

Androgenetic alopecia (AGA) is the most common form of hair loss in men, affecting almost 50% of the male population.⁵² Several other forms of hair loss also exist such as telogen effluvium (TE), alopecia areata (AA), and alopecia induced via chemotherapy.⁵³

In 2007, the FDA approved LLLT as a possible treatment modality for hair loss. ⁵⁴

Multiple studies have shown LLLT to be beneficial in treating hair loss. In male pattern baldness (AGA) patients described significant improvements in overall hair regrowth, a decreased rate of hair loss, thicker feeling hair, improved scalp health and hair shine. About 65% of the patients that receive chemotherapy for cancer develop alopecia. In an animal model hair regrowth proceeded more rapidly after LLLT. ^{55 56 57 58 59 60}