19 Red Light Therapy Facts and Statistics You Should Know in 2023
Scientific Facts About Sunshine
1. The sun’s wavelengths range from 290 nm to over 1,000,000 nm
The sun’s wavelengths that reach the Earth range from 290 nm (ultraviolet) to over 1,000,000 nm (far infrared) (ScienceDirect.com, pubmed.gov).


2. 54% of the sun’s rays are the red and infrared wavelengths that red light therapy uses
Red light therapy uses wavelengths from 630 nm (red) to 1400 nm (infrared). 54% of the sun’s rays are also these wavelengths of red and infrared light (760 nm to 1 mm) (ScienceDirect.com, pubmed.gov).


3. 6.8% of the sun’s rays are ultraviolet
6.8% of the sun’s rays are ultraviolet (UV-C). The UV-B and UV-A rays are blocked by the ozone layer.


4. 38.9% of the sun’s rays are in the visible spectrum
38.9% of the sun’s rays are the wavelengths we can see, which are red, orange, yellow, green, blue, indigo, and violet, and range from about 655 (red) to 42 nm (violet).
5. 660 nm red light provides SPF-15 sun protection
Exposing the skin to 660 nm red light preconditions the skin to resist redness and burning from the sun’s ultraviolet (UVB) rays (ScienceDirect.com, pubmed.gov). A proper dose of red light provides SPF-15 UV protection.


6. The sun’s maximum irradiance is 100 mW/cm^2
Red light therapy devices with irradiance values greater than 100 mW/cm^2 are literally stronger than the sun (ScienceDirect.com, pubmed.gov). In fact, devices over 50 mW/cm^2 are likely to heat the skin and therefore be counterproductive. When they produce heat, they harm rather than help the skin.


Irradiance over 100 mW/cm^2 will create damaging heat. This is too strong!




Scientific Facts About Light Therapy (Visible Light + Infrared)
1. There are at least 9,454 science journal articles about red light therapy
There were 9,454 scientific studies, analyses, and commentaries mentioning some form, of red light therapy as of July 3, 2023 (pubmed.gov)
Since “red light therapy” goes by over 70 names, a search of several of those names yields 9,454 hits in the pubmed.gov database. Searched terms include
- photobiomodulation
- photo biostimulation
- photobiostimulation
- low level laser therapy
- low-level light therapy
- cold laser
- red light therapy
2. Light therapy has an 86.4% to 100% lupus vulgaris cure rate
In 1896, Dr. Neils Ryberg Finsen reported that he used nothing but light to cure 11 out of 11 patients suffering from lupus vulgaris (Sagepub.com, pubmed.gov).


In 1902, Finsen reported using nothing but light to cure 86.4% of 804 patients. He reported that 412 were cured, 192 were nearly cured, and 91 were partially cured. He used nothing but light.
Facts About Red Light Therapy for Wrinkles
1. Red light therapy reduces wrinkles by 36%
Red light therapy led to a 36% reduction in wrinkles among 75 subjects (ScienceDirect.com, pubmed.gov)


2. Red light therapy reduces wrinkles by 26%-75%
Infrared light therapy led to as much as a 75% improvement in two subjects (eymj.org, pubmed.gov). Results were based on self-reporting and independent assessments. Light therapy resulted in a 51-75% improvement in roughness and tightness and a 26-50% improvement in skin color tone and small wrinkle reduction.
3. Red light therapy reduces wrinkles by 90%
Red light therapy led to a 90% reduction in rhytid (skin creases) depth after 12 treatments. The group also had an 87% reduction in the Fitzpatrick wrinkling severity score.


Facts About Red Light Therapy for Acne
If you want the science behind these amazing results from using light therapy to reduce acne, you should know about 13 Ways Red Light Therapy for Acne Works, Based on Studies
The button below is an article about my choices for the best light therapy devices to reduce acne.
1. RLT reduces acne by 81.6%
Blue light therapy led to an 81.6% reduction in inflammatory acne lesions in 12 weeks among 89 subjects (Wiley.com, pubmed.gov). At four weeks in, the subjects had a 40% reduction, and by 12 weeks in, that rose to 81.6%.
2. RLT reduces acne 21.66%
Blue light therapy led to a 21.66% reduction in acne lesions in a 60-subject study (SciElo.br, pubmed.gov). In this study, 93.3% of the benzoyl peroxide users complained of side effects. However, when researchers added blue light therapy to the benzoyl group, the complaints fell to 23.3%.
3. RLT reduces acne by 76%
Blue light therapy led to a 76% reduction in acne lesions in a 124-subject study (jpad.com, pubmed.gov). This study compared blue light therapy to 4% benzoyl peroxide treatment. The blue light group had two sessions per week for 6 weeks. The benzoyl group applied the remedy every night for 6 weeks. At the end of 6 weeks, the blue light group had a 76% reduction in acne lesions, and the benzoyl group had a 60% reduction. Blue light two times a week was more effective than benzoyl 7 times a week.
4. RLT reduces acne by 67.6%
Blue light therapy led to a 67.6% reduction in acne lesions in a 10-subject study (tandfonline.com, pubmed.gov). The 12-minute group did slightly better than the 8-minute treatment group, but don’t extrapolate from that. How long you use a blue light therapy device is very much dependent on its particular specifications.
5. RLT reduces acne by 76%
Blue light therapy led to a 76% acne reduction in acne lesions in a 30-subject study (tandfonline.com, pubmed.gov). After four treatments, there was a 76% reduction in average lesion size.
6. RLT reduces acne by 62.3%
Red and blue light therapy led to a 62.3% reduction in acne lesions in a 24-patient study (journals.lww.com, pubmed.gov). Blue alone reduced acne by 35.2%.
7. RLT reduces acne by 63%
Red and blue light therapy reduced inflammatory acne lesions by 63%, and comedones by 45% in a 107-patient study (academic.oup.com, pubmed.gov).
8. RLT reduces acne by 52%
Blue light therapy reduced acne lesions by 52% in a 31-patient study (Wiley.com, pubmed.gov).


Red Light Therapy (RLT) Brain Facts
1. RLT increases blood flow in the brain by 30%
Two-minute treatments of 627 nm red light in 8 sessions over 4 weeks increased subjects’ systolic velocity by 25% and diastolic velocity by 30% in the left middle cerebral artery (springer.com, pubmed.gov). The red light increased basilar artery systolic velocity by 17%, and diastolic by 25%.

