Visible light therapy is used to treat mild to moderate acne outbreaks. Blue light therapy and red light therapy are both types of phototherapy.


Phototherapy is safe for nearly anyone, and side effects are mild.


This kind of therapy is fairly easy to access, and can be administered in a dermatologist’s office. There are also products available to do this treatment at home.


Depending on the cost of living in your area, phototherapy usually costs $40 to $60 per session. Typically, you’ll need several sessions to see results.


Phototherapy is remarkably effective for treating acne lesions, especially acne that’s caused by inflammation or bacteria. While there’s no cure for acne, phototherapy is backed up by significant research as an acne management tool.

Even with various oral and topical treatments available for acne symptoms, many of the 50 million people with acne are dissatisfied with their results or the side effects of those treatments.

Visible light devices that kill bacteria on the skin have been used by dermatologists as an alternative acne treatment for the past 20 years. Light therapy — also called blue light, red light, or phototherapy — is a research-backed treatment that’s safe for most people and relatively free of side effects.

There are two main kinds of visible light therapy used in clinical settings: blue light and red light. Each has a specific use, and, while they both help acne, each has different benefits.

Blue light therapy

Blue light therapy is the type of light therapy most commonly used to address acne breakouts.

The wavelength of blue light has an antimicrobial effect, making it effective at killing several types of bacteria that can collect in your pores and oil glands and cause breakouts.

In one study, people with acne who were treated for five weeks with blue light therapy saw improvement in 77 percent of cases.

Blue light therapy also helps condition your skin, getting rid of free radicals that oxidize and age your face. The treatment also has anti-inflammatory benefits, which decreases other symptoms of acne, such as redness.

Red light therapy

Red light therapy doesn’t have the same antibacterial effects of blue light therapy, but it can still be effective.

Red light therapy helps promote healing and may work to decrease the visibility of acne scarring. It also has anti-inflammatory capabilities.

Red light therapy works deep below the surface of your skin to help soothe and repair tissue. If your acne is caused by a chronic skin condition, red light therapy might be the choice for you.

Before you have a phototherapy session, you’ll see a dermatologist. They’ll be able to tell you if you’re a good candidate for this treatment, what kind of light they’ll be using, what to expect, and how many treatments you might need.

For two weeks prior to a light therapy session, you may need to avoid retinols and other skin care products that thin your skin.

If you’re on any anti-inflammatory drugs, ask your dermatologist if you should discontinue them. Avoid tanning beds and prolonged, unprotected sun exposure in the days just before your treatment appointments.

Blue and red light therapy sessions last 15 to 30 minutes each. During the session, you’ll lay down or put your head in a special device meant to keep your face still.

A trained light therapy professional — usually a nurse or dermatologist — will apply pulses from a light therapy device to different parts of your face, working in a circular fashion. After several repetitions of this process, the treatment is complete.

After phototherapy, your treated skin may be pink or red. There might be some mild skin peeling from the treated area.

Your skin may be more sensitive, and you might need to skip your typical skin care regimen for a few days afterward, especially scrubs, exfoliants, and topical vitamin A.

While dermatologists recommend you wear sunscreen every day, you’ll need to be especially vigilant with sunblock while your skin recovers.

According to the American Academy of Dermatologists, visible light therapy isn’t effective for whiteheads, blackheads, or nodular acne. It works best for people who have mild to moderate acne.

Phototherapy rarely involves a single treatment. Several rounds of phototherapy, typically two to three treatments per week, over the course of four to six weeks, is usually recommended to start.

After that, the effects of the treatment may need to be maintained by occasional follow-up treatments every three months or so. These treatments tend to run an average of $50 a session, and aren’t typically covered by most insurance.

Blue light therapy and red light therapy are generally considered safe, but there are some side effects.

common side effects of light therapy
  • redness
  • bruising
  • skin peeling
  • mild pain or irritation

Less often, other side effects develop as a result of this treatment. Rare side effects include:

  • dried pus or blistering at the site of treatment
  • burns
  • dark pigmentation as a result of overexposure to the sun after treatment
  • severe pain at the site of treatment

The light used in phototherapy isn’t ultraviolet, so it doesn’t carry the risks of skin damage and radiation. But that doesn’t mean there are no risks to this treatment.

If the treated area isn’t cared for properly, there’s a chance for infection. If you notice pus, blistering, or develop a fever after light therapy, call your healthcare provider immediately.

There are also people who should avoid light therapy. If you’re currently taking antibiotics, or if you’re extremely sensitive to sunlight or easily sunburned, you might not be the best candidate for light therapy for acne.

You should also avoid this type of treatment if you’re pregnant or believe you could be pregnant.

There are some products on the market for at-home light therapy treatment. In the last few years, light treatment masks and light devices that administer blue light therapy have become popular.

Research suggests that these treatments can be effective — one small study found that using self-applied blue light therapy for 28 days did reduce the number of acne lesions on participants’ faces.

Light therapy devices for home use may seem a bit pricey (one popular treatment device is $30 for 28 days of treatment), but in comparison to the price of rounds of acne treatment in a dermatologist clinic, it is a cost savings.

On the other hand, while light therapy done at home probably works, there’s no evidence to suggest that it works as effectively as professional treatment.

For many people, visible light therapy is effective for the treatment of acne.

It’s important to have realistic expectations for how well light therapy can work for you. While it may improve your symptoms, it probably won’t get rid of your blemishes and pimples indefinitely.

It’s also usually recommended that you try other, less expensive methods of topical and oral acne treatment before you try light therapy. Speak to your dermatologist to see if you’re a good candidate for this type of acne treatment.