13 Ways Red Light Therapy for Acne Works, Based on Studies
Acne is a condition in which the skin erupts in whiteheads, blackheads, cysts, papules, pustules, and nodules. Red light therapy for acne is the use of low-energy visible and infrared light to trigger healthy responses.
Red light therapy for acne is scientifically proven to provide these benefits:
- reduction of the number of acne bumps
- reduction in the severity of eruptions
- reduction in clogging of hair follicles
- reduction and elimination of P. acnes bacteria
- reduced sebum (oil)
- more even skin tone
- reduced inflammation
- SPF-15 sunscreen level of UV protection
- increased collagen and elastin
- tighter skin
- reduced sagging skin
- reduced redness
- increased blood flow to nourish tissue health
Takeaways
- Several controlled studies on red light therapy for acne show that light therapy significantly reduces acne
- These studies showed that blue, yellow, red, and infrared light are effective against acne
- Red light therapy naturally reduces inflammation and redness and speeds up healing
- If you haven’t already seen it, I recommend some devices specifically for acne in my articles here: You Can Drop 80% of Your Acne in 4 Weeks Using this Device
What is Acne?
Acne is a common skin condition that occurs when hair follicles become clogged with oil and dead skin cells, and bacteria infect the skin.
The most common types of acne eruptions include:
- Whiteheads are small, round, white bumps caused by hair follicles becoming clogged with oil and dead skin cells.
- Blackheads are small, flat, black, or dark-colored bumps caused by clogged hair follicles that are exposed to air.
- Papules are small, raised, red bumps caused by inflamed hair follicles.
- Pustules are small, raised, red bumps caused by inflamed hair follicles that are filled with pus.
- Nodules are large, painful, solid bumps that develop deep under the skin.
- Cysts are tender nodules that are filled with pus.
Psychological Effects of Facial Acne
The psychological impact of facial acne includes self-consciousness and social anxiety. According to a 2018 review of acne’s psychological effects, the condition can cause professional stress, private concerns, anxiety, and difficulty sleeping[i]. Stress and anxiety can lead to behaviors that make acne worse, such as skin picking. The acne can morph into post-inflammatory hyperpigmentation, which compounds self-consciousness and anxiety.
Acne Symptoms
Acne causes lesions and bumps including whiteheads, blackheads, papules, pustules, nodules, and cysts. Symptoms also include tenderness, redness, and inflammation.
Acne Whiteheads
A whitehead, also known as a closed comedo, is a type of acne lesion that appears as a small, raised bump on the skin with a white or yellowish head.
It is caused by the buildup of oil, dead skin cells, and bacteria in the hair follicles of the skin, which can block the opening of the follicle and cause a small, closed bump to form.
Whiteheads are typically less than 5 millimeters in size and are not inflamed or red.
They are a common type of acne and can occur on the face, neck, chest, and back.
Whiteheads can be treated with a variety of topical and oral medications, depending on the severity and duration of the acne.
Acne Blackheads
A blackhead, also known as an open comedo, is a type of acne lesion that occurs when a hair follicle becomes clogged with oil, dead skin cells, and bacteria. The clogged material oxidizes and turns black, resulting in a characteristic dark appearance.
Blackheads typically appear on the face, neck, chest, and back, and are more common in people with oily skin. They are a mild form of acne and can be treated with various topical and oral medications, as well as regular skincare practices such as gentle cleansing and exfoliation.
Acne Papules
Papules are a type of acne lesion that appears as small, raised bumps on the skin. They are typically less than 5 millimeters in size and may be pink, red, or flesh-colored.
Papules are caused by inflammation and clogging of the hair follicles in the skin, leading to the formation of a small, solid bump.
They can be painful or tender to the touch and may be accompanied by other types of acne lesions such as pustules or nodules.
Papules are a common type of acne and can occur on the face, neck, chest, and back. They can be treated with a variety of topical and oral medications, depending on the severity and duration of the acne.
Acne Pustules
Pustules are a type of acne lesion characterized by a small, raised bump on the skin that contains pus.
They often have a red base and may be painful or tender to the touch.
Pustules are typically filled with white or yellowish fluid and can occur anywhere on the body, but are most commonly found on the face, neck, chest, and back.
They are caused by inflammation and infection of the hair follicles, which can be triggered by a variety of factors including excess oil production, bacterial overgrowth, and hormonal changes.
Acne Nodules
Acne nodules are a severe form of acne lesion that typically develop deep within the skin.
Nodules are large, hard, painful bumps that can be up to several centimeters in size.
Nodules are caused by the build-up of oil, dead skin cells, and bacteria within hair follicles. The immune system responds with inflammation of the skin.
Nodules can develop anywhere on the body but are most commonly found on the face, neck, chest, and back.
Unlike other types of acne lesions, nodules do not have a white or black head on the surface, and they do not come to a head. Instead, they are deeply embedded in the skin and can be difficult to treat.
Nodules can also lead to scarring if they are not treated properly.
Do you have acne scarring? You might want to check out the acne scarring series:
Acne Cysts
An acne cyst is a clustered of pustules[ii]. Acne cysts are a severe form of acne, characterized by large, pus-filled lesions that are deep-seated within the skin. They can be painful and may take a long time to heal. Cysts are formed when the contents of a blocked hair follicle spill out into the surrounding skin, leading to inflammation and infection. The cysts can be difficult to treat and may leave scars.
Acne Causes
According to a 2021 medical overview of acne vulgaris[iii], the disorder is caused by problems with sebum, follicles, bacteria, and inflammation.
Increased Sebum Production
Sebum is an oily, waxy substance produced by the sebaceous glands in the skin. It helps to lubricate and waterproof the skin and hair.
Increased sebum production can contribute to several symptoms of acne, including oily skin, clogged pores, and the formation of whiteheads and blackheads.
Excessive sebum production can also create an environment that is conducive to bacterial growth, which can lead to the development of inflammatory acne lesions such as pustules and cysts.
Hyperkeratinization of the Follicle
Hyperkeratinization of the follicle is a medical condition in which there is an overproduction of keratin, a protein that helps protect the skin, within the hair follicles. This can cause the follicles to become blocked, leading to the formation of whiteheads, blackheads, and other types of acne lesions.
Bacterial Colonization
Bacterial colonization refers to the process by which bacteria take up residence and multiply in a particular area of the body.
In the case of acne, the skin’s sebaceous glands can become colonized with a type of bacteria called Propionibacterium acnes (P. acnes). This can lead to the development of inflammatory acne lesions, as the bacteria produce enzymes and other substances that can cause irritation and inflammation. Additionally, P. acnes can contribute to the formation of comedones (clogged pores) by breaking down the sebum within the follicles.
Inflammation
Inflammation is a natural response of the body’s immune system to injury or infection. It is characterized by redness, swelling, warmth, and pain in the affected area.
In the case of acne, inflammation can occur when the hair follicles become blocked with sebum and dead skin cells, leading to the formation of whiteheads, blackheads, and other types of acne lesions.
When the bacteria P. acnes colonize the follicles, they can produce substances that trigger an inflammatory response, causing redness and swelling around the affected area. Inflammatory acne lesions, such as papules, pustules, and cysts, are a result of this process.
In some cases, inflammation can also contribute to the development of acne scarring. Red light therapy is very good at reducing these scars, learn more in my article Red Light for Acne Scars
Acne Treatment Options (Including Red Light Therapy for Acne)
Acne treatments come in topical, oral, and physical intervention forms. The information in this section was sourced from the Mayo Clinic’s page on Acne.
Topical Acne Treatments
Topical treatments include retinoids that are derived from vitamin A. Retinoids prevent hair follicles from plugging up, but do not treat the bacterial cause of acne. They can cause redness and dry skin.
Topical antibiotics can address the bacteria but don’t work well in isolation. Retinoids and antibiotics are often prescribed together.
Azelaic acid is both an acne and melasma treatment (melasma is a hormonal hyperpigmentation). This topical prevents hair follicle clogging, but not bacterial colonies. Azelaic acid can cause skin irritation.
Medical Acne Treatments
Medical acne treatments include antibiotics, contraceptives, androgen inhibitors, and Isotretinoin.
Antibiotics are photosensitive medications that cause a rash when you are exposed to the sun. They restrain the P. acnes bacteria that colonize the skin.
Contraceptives change the estrogen profile in your body. They can prevent acne-causing processes but have a huge side effect profile. Contraceptives can cause breast cancer, cervical cancer, and cardiovascular disease.
Anti-androgens prevent hormones from triggering acne-causing processes in the skin. They can cause period and breast pain.
Isotretinoin is a derivative of vitamin A with enormous side effects and problems that include depression, birth defects, and inflammatory bowel disease.
Skin Intervention Acne Treatments
Skin interventions for acne include using blue, red, and infrared wavelengths, as well as chemical peels, drainage/extraction, and steroids.
Acne interventions:
- blue, green, red, and infrared light
- chemical peels
- drainage/extraction
- steroids
Chemical peels can give a short-term improvement in the skin’s collagen profile but do not really affect the acne processes underlying the problem.
Drainage and extraction involve the doctor draining the pimples. Extraction can cause permanent scars.
Steroid injections are therapeutic for a small subset of acne cases to reduce inflammation.
What the Science Says About Red Light Therapy for Acne Relief
Infrared, red, and blue light combined and by themselves reduce acne symptoms.
Blue light kills P. acnes bacteria. Red and infrared light stimulate collagen production and reduce inflammation.
Specifically, this is the mechanism of action that causes acne to reduce in severity and area:
- The affected skin absorbs the light energy in the mitochondria, which are where the cells make energy molecules (adenosine triphosphate, or ATP) that power repair processes
- The mitochondria signal the production of growth factors that produce new skin cells
- The mitochondria also signal the immune system to stop chronic inflammation, a key component of acne symptoms
- The light stimulates porphyrins (organic compounds) in the bacteria to release reactive oxygen species (free radicals) that also kill the P. acnes bacteria.
- The blue light kills the P. acnes bacteria colonized in the hair follicles
Taken together (literally at the same time, or alternating between the different types of light), red light therapy:
- reduction of the number of acne bumps
- reduction in the severity of acne eruptions
- reduction in clogging of hair follicles
- reduction and elimination of P. acnes bacteria
- reduced sebum (oil)
- more even skin tone
- reduced inflammation
- SPF-15 sunscreen level of UV protection
- increased collagen and elastin
- tighter skin
- reduced sagging skin
- reduced redness
- increased blood flow to nourish tissue health
Scientifically Proven Benefits of Red Light Therapy for Acne Relief
Here are just a few of many studies that successfully reduced acne symptoms using red light therapy.
Infrared Light Reduces Sebum and Pustules
A 2021 study of one acne reduction treated 27 women six times with infrared light[iv]. Independent observers assessed the acne before and after treatments.
Average sebum production on the forehead and cheeks dropped significantly by the third treatment and continued to drop after that.
Blackheads dropped from an average of 23 to 10; pustules dropped from an average of 12 to 8 per person; and papules dropped from an average of 9 to just 5 per person.
Blue Light Produces an 81.6% Reduction in the Number of Acne Lesions
A 2016 randomized and placebo-controlled study treated 89 people twice a week for 12 weeks with blue light therapy[v].
At 6 weeks, the was an average drop of 40% in the number of inflammatory lesions. Half the group then received another 6 weeks of treatment, achieving an 81.6% reduction in the number of lesions.
Blue Light Therapy is Equivalent to Benzoyl Peroxide without Side Effects
A 2009 study compared blue light therapy to treatment with benzoyl peroxide 5% in 60 subjects[vi]. Thirty received benzoyl peroxide twice a day, and 30 received blue light therapy once a day, each for 4 weeks.
The benzoyl peroxide group achieved a 31.32% reduction in lesions[vii], but 23% of that group complained of side effects. The blue light therapy group had a 21.66% reduction in the number of lesions, with no reported side effects.
Red and Infrared Light Reduce the Number of Lesions
A 2021 study compared red to infrared light therapy for the reduction of acne in 28 subjects.
The red light group started with an average of 27.7 pimples and finished the study with an average of 6.3.
The infrared therapy group did not have a significant drop in the number of pimples. Since other studies using infrared by itself produced excellent results, we can attribute this to the dose and not a failure of the wavelength.
Red and infrared excel at reducing inflammation. Blue light excels at reducing the number of pimples. However, blue light has some inflammatory effects; red and infrared light can reduce the number of pimples. They work best together.
Science of How Red Light Therapy Reduces Acne
By far the most satisfying mechanism of red light therapy is how it kills the Cutibacterium acne (C. acne)[viii] and Propionibacterium acnes (P. acnes) bacteria.
Blue and red light both have the capacity to kill bacterial colonies. Blue light is more effective than red[ix] light.
The light excites organic compounds in the bacteria that cause acne, causing the organic compounds to vibrate faster. The excitation creates free radicals that turn around and kill the bacteria that host them.
Bacteria become resistant to antibiotics, but not to red light therapy. The bacteria cannot become resistant to light; it has no choice but to absorb photons in their organic compounds.
Bacteria would have to evolve over eons to adapt to red and blue light therapy.
Red light therapy also reduces highly inflammatory proteins in the skin that is affected by acne.
Nitty Gritty Science of Red Light Therapy for Acne Reduction
Porphyrins in Acne
Porphyrins are a group of organic compounds. Cutibacterium acne (C. acne)[x] and Propionibacterium acnes (P. acnes) bacteria on the skin produce porphyrins as part of their normal metabolism.
Red and blue light is absorbed in the porphyrins[xi]. The molecular excitation results in the production of singlet oxygen, a free radical that then kills the bacteria. The skin recovers when the bacterial colonies are killed.
Interleukin-1 Beta (IL-1β) and Interleukin-6 (IL-6) in Acne
Interleukin-1 beta (IL-1β) is a pro-inflammatory cytokine that plays a crucial role in the body’s immune response. It is produced in response to infection, injury, or inflammation. IL-1β is involved in acne inflammation. It can cause tissue damage and chronic inflammation.
Interleukin-6 (IL-6) is a pro-inflammatory cytokine that responds to infection and inflammation. IL-6 is involved in acne formation as well as chronic inflammatory diseases.
Red and blue light significantly reduces the levels of IL-1β and IL-6, causing acne reduction[xii].
Red light therapy causes retrograde signaling from the mitochondria that call for inflammation reduction. That mechanism might be the one that causes IL-1β and IL-6 to drop in skin affected by acne.
How To Use Red Light Therapy for Acne
You can do red light therapy for acne at home. The ideal device uses infrared, red, yellow, and blue wavelengths of light. The most common devices for acne are face masks and tabletop panels. See my light therapy mask recommendations, as well as my favorite light devices for better skin.
You must know how long to expose yourself to the light (usually between 5 and 20 minutes). Equally important, you must know the distance of the light to your face or other target. If the instructions say 6 inches, use a ruler to measure 6 inches. Don’t guess. The amount of light you get changes exponentially with distance.
With the device at the right distance, turn on the device aimed at your face for the instructed treatment time. Do the treatment every day unless instructed otherwise.
What About Photodynamic Therapy for Acne
Photodynamic therapy is the use of light to activate a substance, and then that substance becomes the source of healthy biological change. Dermatologists use photodynamic therapy, but it is not something that makes sense for home use.
Conclusion
Red light therapy by itself reduces acne, and blue light is a powerful force for killing acne bacteria. Controlled studies repeatedly show that red light therapy (with or without blue light) works to reduce acne. In addition to the acne article I posted at the top, here’s another look at some acne lights: 2 ReVive Acne Relief Devices: Are They Worth It?
Red Light Therapy for Acne FAQ
What is red light therapy?
Red light therapy is a type of light therapy that uses red light to treat various conditions, including acne. It works by delivering specific wavelengths of light to the skin to help heal and reduce inflammation.
How does red light therapy treat acne?
Red light therapy for acne targets the skin’s sebaceous glands, which are responsible for producing oil that can lead to acne vulgaris. The light wavelengths penetrate the skin and help to reduce the production of oil and inflammation. It also promotes new tissue growth and aids in healing acne lesions and scarring.
What is the difference between red light therapy and blue light therapy?
Red light therapy and blue light therapy are both used in the treatment of acne. Red light therapy targets the sebaceous glands and reduces inflammation while blue light therapy targets the bacteria that cause acne. Some devices use both red and blue light for an even more effective treatment.
How often should I use red light therapy for acne?
The frequency of treatment sessions depends on the severity of your acne. Typically, at-home devices can be used daily for mild-to-moderate acne, while more severe acne may require more frequent treatments. It’s important to follow the instructions provided with your red light therapy device or to consult a dermatologist to determine the best treatment plan.
Can red light therapy be used for inflammatory acne?
Yes, red light therapy can be effective for treating inflammatory acne. The light wavelengths penetrate the skin and promote healing and reduce inflammation, which can help to reduce the severity of acne flare-ups.
Is red light therapy safe for the skin?
Red light therapy for acne is considered safe for most individuals. It is non-invasive and does not cause damage to the skin. However, it is important to use the light therapy device as directed and to avoid prolonged exposure to the light.
What is the difference between red light therapy and laser therapy?
Red light therapy typically uses light-emitting diodes (LEDs) but is also done with lasers. Laser and LED light have different properties, but the same effects on the skin. The issue when comparing them is the LEDs can be too weak and lasers can be too strong. To make an effective red light therapy device, the LED needs more power, and the laser needs less.
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