Acne Light Therapy – The Acne-Fighting Science Behind Light Therapy
Acne light therapy is the biggest exception in the industry right now. Very specific kinds of light can help improve the acne you currently have, and when used in conjunction with a preventative acne treatment system, you can see real improvement in your acne, without the initial backsliding.
The vast majority of treatment processes for acne right now are all about prevention; there are very few treatments that actually help heal acne you already have. This means that what your doctor suggests may make acne worse at first, which can be frustrating and discouraging. It’s difficult to keep up with a complicated (and often expensive) treatment plan when it seems like it’s not working.
- Although it can be easy to dismiss acne light therapy as just another skin care fad, independent research and dermatological organizations support its use
- A brief physics lesson can help explain why exactly light therapy works
- Blue light therapy and red light therapy work differently with the skin
- Different skin types and acne types benefit from different color light therapy
- Acne light therapy could be a good replacement for isotretinoin treatment
- Don’t get your hopes up for a miracle treatment—acne light therapy has its drawbacks
- Light therapy has dermatological uses beyond acne as well
- Know what to expect from your first acne light therapy session at a dermatologist’s office
- Home light therapy options are often less effective
Acne Light Therapy is American Academy of Dermatology Approved
It’s good if you’re a little bit skeptical of acne light therapy, because you want to be absolutely sure any new acne treatment is safe and effective before trying it. Research is an important part of skincare.
However, we don’t all have time to scour the internet to find the best sources, and how they compare with other reliable sources, and what some of the science jargon means. This article will try to do all of that for you, citing its sources along the way so you can follow up and read for yourself if that nagging skepticism continues.
As of 2018, acne light therapy is supported by the American Academy of Dermatology¹, and studies about light therapy², or these³, provide solid evidence that their support is not misguided. The science behind light therapy is very different from typical acne treatments, but it is still effective. But how, exactly, can it be effective? How does putting a colorful light close to your face actually do anything?
If you’ve ever been told that you should lay out in the sun to “dry out your acne,” you may have gotten your first introduction to light therapy, albeit a misguided one. Laying out in the sun can sometimes improve acne, but not because the skin is drying out. Sunshine can help with acne because of the kind of light your skin gets exposure to, namely blue and red visible light. The negative side effects of drying, burning, and UV exposure make sunshine an unsafe, impractical acne solution.
Acne light therapy today uses only the blue or red wavelengths of light to kill bacteria, reduce oil production (otherwise known as sebum), and reduce inflammation, harnessing the benefits of sunshine without the dangerous UV rays.
A Little Physics Goes a Long Way
To understand why acne light therapy works, you’ll have to take a brief stroll down memory lane, to middle school science when you learned about the spectrum of visible light4. Light travels in waves, repeating peaks and valleys, and different kinds have different wavelengths and frequencies. To understand wavelength, you just have to measure the distance from one peak to the next.
Frequency is a little trickier because it’s almost like speed but not quite. All light travels at the speed of light, but because different types have different wavelengths, they also have different frequencies. Imagine you can see a light wave and you count the peaks as they go by you for one second. Even though all kinds of lights would move at the same speed, you would count more peaks for lights with short wavelengths, and fewer peaks for ones with longer wavelengths.
So what does this have to do with treating acne? To understand why light therapy really works and isn’t just the latest craze, you need to understand the wavelengths and frequencies of blue and red light. Blue light is on the high frequency, short wavelength end of the spectrum, and red light is on the low frequency, long wavelength end of the spectrum. Clearly they are very different, so the way they treat acne is just as different.
Blue Light and Red Light Acne Treatments
How Blue Light Works: Blue light is most effective at fighting acne-causing bacteria5. This is because of something called resonant frequency.
Think of the opera singer who breaks the glass just by singing. Everything in the universe has a resonant frequency, or a speed at which it will vibrate if bumped or disturbed. When the opera singer hits a note with the same frequency as the glass’ resonant frequency, it shatters.
With acne light therapy, blue light is the opera singer and the bacteria are the glass. Acne is caused by a specific kind of bacteria called p. acnes, which grows on the skin at normal rates all the time, as part of the normal ecosystem of the human body. However, sometimes the bacteria will grow in number, or the skin will get inflamed, trapping bacteria and causing a minor infection that results in a pimple.
Blue light therapy works because the frequency of the light matches up with the resonant frequency of a chemical in the membrane of p. acnes called porphyrins. When the two frequencies meet, it excites the porphyrins, causing them to vibrate and break apart the membranes of the bacteria.
How Red Light Works: Red light is most effective at reducing sebum production because of its wavelength.
Red light is directly next to infrared light on the spectrum. We can’t see infrared light, but we feel it as heat. Red light used for acne is somewhat like a very gentle heater. It can heat the sebum that clogs pores and remove it, and because red light has a larger wavelength, it can travel farther into the skin. Unlike blue light, red light doesn’t stop at the bacteria on the surface, it reaches to the sebaceous glands that form the sebum. Red light activates the release of anti-inflammatory chemicals that can shrink sebaceous glands and reduce the production of excess sebum that could be leading to acne.
Which Kind of Light is Best for You?
Whether you need red light or blue light (or a combination of both) largely depends on your skin type and what kind of acne you usually have. If you have a dry or normal skin type, you should be cautious about using red light. Because red light shrinks sebaceous glands, it can dry out skin, which would be counterproductive for dryer skin types. Blue light can be an ideal treatment for those with dry or sensitive skin, because it can destroy bacteria without irritating your skin the way many topical treatments might.
On the other hand, if you have oily or combination skin, red light could make a significant difference—if your acne is mostly blackheads and whiteheads. If you have more pimples, then you may want to try a combination treatment, using both red and blue light. Blue light kills bacteria in pimples, while red light reduces oil and inflammation common in blackheads and whiteheads.
People with dark complexions should be cautious about using acne light therapy of any color. According to the American Academy of Dermatology, light and laser therapies can lead to hyperpigmentation or skin darkening in dark skin. But they also say that light therapy can be effective for dark skin, if done correctly6. To make sure your skin is being treated with care, you may want to research reviews for dermatologists in your area, or get recommendations from light therapy forums online. The AAD also recommends asking the dermatologist how many people of color they have treated.
Acne Light Therapy Could Provide Another Treatment Option for Cystic Acne
Before light therapy, isotretinoin was considered one of the only effective treatments for severe cystic acne. However, more and more studies are coming out saying that isotretinoin could stay in the body’s system longer than anticipated and could have longer lasting effects. It is also known to be highly teratogenic, meaning it can cause serious health risks or birth defects if taken while a mother is pregnant, and there is anecdotal evidence suggesting it can lead to serious mood problems. Because of all of these risk factors many people with cystic acne have been searching for a different option.
There are relatively few studies done on light therapy and cystic acne, but there is rising evidence that a specific kind of light therapy could help: photodynamic therapy. In addition to exposing the skin to red, blue, or red and blue light, photodynamic therapy includes a photosensitizing agent to increase the impact of the light therapy. The dermatologist applies either aminolevulinic acid HCL (ALA) or methyl aminolevulinate (MLA) to the face, then lets it sit for up to three hours. This gives the photosensitizing chemicals time to absorb into the skin, all the way to the sebaceous glands.
After the chemicals have had time to absorb, light is shone onto the skin for 15-20 minutes. The light activates the photosensitizing chemicals and kills bacteria deep in the skin. The infection involved in cystic acne often lies further below the skin than most acne treatments can reach, so it may respond better to photodynamic therapy because it is specifically made to kill acne-causing bacteria deep in the skin.
Although this treatment can be effective, be sure you’re aware of the side effects. Unlike traditional light therapy, photodynamic therapy can be painful during the procedure, and skin is highly sensitive and red for several days afterward.
Don’t Trust Any Article or Dermatologist Saying It’s the Miracle Cure
Although there is some solid science behind why acne light therapy works, and many studies have shown success with this treatment, you should still be wary of anyone who talks about it like a miracle cure. There is no miracle cure for most things, and definitely not for acne.
For instance, light therapy has been shown to be significantly more effective on inflammatory acne like pimples, rather than non-inflammatory acne like blackheads or whiteheads. This doesn’t make it ineffective, it just means it can’t cure everything. Many studies show that while participants showed significant improvement, light therapy did not clear their skin entirely. Additionally, be suspicious of companies or articles that advertise quick results with light therapy.
The American Academy of Dermatology and other reputable acne associations emphasize that it typically takes at least 3 treatments to see an improvement, and that immediately after treatment your skin may actually be a little red or sore, not magically zit-free.
That doesn’t mean it isn’t a great treatment, it just means that you should also develop an effective, everyday acne routine, like Exposed Skincare. We recommend this acne treatment system because of the way they balance their ingredients. They combine active acne-fighting ingredients like benzoyl peroxide and glycolic acid with natural, soothing ingredients like passion flower extract and green tea, and the result is excellent skincare for acne.
They also make a corundum crystal microderm scrub that can improve your results from acne light therapy. In order to kill bacteria or reduce sebum production, the light needs to get through to your skin, so before treatment, some dermatologists recommend a gentle exfoliation to clear the skin of dead skin cells that could block the light.
Light Therapy Can Help With Other Dermatological Needs
Although light therapy can help with acne, it can also improve other skin conditions, like MRSA or the normal effects of aging.
MRSA, or methicillin-resistant Staphylococcus aureus, is a staph infection that is resistant to typical staph infection antibiotics7. Typically, those with MRSA are prescribed a different antibiotic and are instructed to keep the area of infection as clean as possible, but treatment can drag on as the infection fights its way back. However, some studies show that blue light can effectively kill bacteria in MRSA8. Unlike the antibiotics, which try to kill the bacteria with chemicals that they’ve become resistant to, blue light kills bacteria through its frequency, which matches the frequency of some bacteria, including MRSA, causing the bacteria’s membranes to burst.
Light therapy may also be helpful in treating wrinkles around the face. Wrinkles are a healthy part of aging, but if you’d like to delay their appearance, some studies show that red light therapy can reduce wrinkles, through encouraging collagen production and reducing inflammation.
What to Expect: First Acne Light Therapy Session
Before you schedule an appointment for acne light therapy, you should know the cost. One session costs an average of $40, but for good results, most dermatologists recommend one to two sessions a week for several weeks, so that number can go up quickly. It’s also important to know that insurance does not usually cover acne light therapy.
On the day of your appointment, do not wear any makeup. Some doctors will advise you to use a gentle exfoliating facewash, but others might recommend against it. It’s always best to listen to your doctor.
To start treatment, the doctor will give you a pair of goggles to protect your eyes from the bright light, and you will lie or sit down in front of a large blue light. Treatments typically last anywhere from 15 to 30 minutes, and you should not feel any pain or discomfort from the light.
After treatment, you should be able to go on with your day as normal. There are no immediate side effects to worry about except some mild inflammation or redness that should fade quickly. Makeup can usually be applied right after treatment, but check with your doctor first.
You should start seeing results after 2 or 3 weeks of light therapy sessions, and will likely need consistent treatment to maintain positive results.
Home Light Therapy Products Work Best for Mild Acne
If you have relatively mild acne, a home light therapy treatment like a light wand or mask could definitely work for you. These at home products work just the same way they would at a dermatologist’s office, but they usually use a weaker light source. This means they typically aren’t as effective at treating moderate acne, and take longer to show results. It’s important to note that using the product for longer periods of time, more times per week, or closer to your skin than instructed will not speed results. Usually this just leads to heightened skin irritation or mild burns.
There’s a wide variety of home light therapy products on the market. Some emit blue light, red, or both, and they cover a broad price range. The most affordable option is a $15 red and blue light spot treatment stick from Neutrogena, while the upper end includes at home light boxes and lamps for several hundred dollars. The more expensive options sometimes use a stronger light, so if you have gone to the dermatologist and found that light therapy works for you, it may be a more cost-effective option than continuing to receive treatments at the dermatologist’s office. However, more expensive does not always mean stronger or better, be sure check out the product thoroughly before investing in a more expensive light or lamp.
Frequently Asked Questions:
What’s the difference between acne laser therapy and acne light therapy?
There are a few key differences, but the biggest difference is that one is specific and the other is general. A laser treatment uses a very narrow beam to treat very specific areas, rather than a light that spreads out over a broad space. Additionally, lasers are often more specialized than regular light treatments, and are used to treat very specific things, like acne scarring, hyperpigmentation from acne, or cystic acne. Although it can be used to treat hyperpigmentation, it can also cause hyperpigmentation9, especially in people with dark skin. Laser and light therapies have this in common, along with their temporary nature. Neither laser nor light therapies will treat acne completely or permanently.
One last key difference is that laser therapy can be much more expensive, ranging anywhere from $75 to $3000 for one treatment.
It’s also important to note that light therapy is more widely researched. While some dermatologists claim that laser therapy is more effective than light therapy, others argue that the effects of laser therapy haven’t been significantly proven, as much of the research done on laser therapy uses very small groups of participants that may not accurately reflect their results.
If I want to try photodynamic therapy to treat my cystic acne, do I have to stop taking my isotretinoin?
Yes, it is very important that you discontinue use of isotretinoin before trying any kind of acne light therapy, especially photodynamic. Isotretinoin makes your skin very sensitive to light, so exposing it to more light, or adding a photosensitizing agent to your skin and then exposing it to light could cause a lot of pain and damage your skin. If you’d like to try light therapy, talk to your dermatologist about stopping the isotretinoin.
Will light therapy help with my hormonal acne?
Because hormones often cause an increase in sebum production, red light therapy could help with hormonal acne. The red light would reach to the sebaceous glands and shrink them slightly to reduce sebum production like it does with all other acne. However, because hormonal acne has a constant fuel of hormones to keep producing more oil, red light therapy will likely be less effective, and those effects will probably last for a shorter amount of time, as compared to when it treats non-hormonal acne.
- Lasers and lights: how well do they treat acne?. American Academy of Dermatology (Website). Accessed 2019.
- Pei S., Inamadar A., Adya K.A., Tsoukas M.M. Light-based therapies in acne treatment. Indian Dermatology Online Journal. 2015;6(3):145-157.
- Light therapy-blue and/or red light. Acne.org (Website). Accessed 2019.
- Tour of the electromagnetic spectrum. NASA Science (Website). Accessed 2019.
- Colored light sources lighting the way for new office-and home-based skin devices. American Academy of Dermatology (Website). Accessed 2019.
- 10 tips for clearing acne in skin of color. American Academy of Dermatology (Website).
- MRSA infection. Mayo Clinic (Website). Accessed 2019.
- Makdoumi K., Hedin M., Bäckman A. Different photodynamic effects of blue light with and without riboflavin on methicillin-resistant Staphylococcus aureus (MRSA) and human keratinocytes in vitro. Lasers in Medical Science. 2019.
- Oram Y., Akkaya A.D. Refractory postinflammatory hyperpigmentation treated fractional CO2 laser. Journal of Clinical and Aesthetic Dermatology. 2014;7(3):42-44.
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