Can colored lights really treat acne?

Phototherapy Results and Side Effects
Studies have shown that phototherapy treatments only last around six months.
Studies have shown that phototherapy treatments only last around six months.
John Rensten/Getty Images

Dermatologists have conducted several small-scale studies on blue light photodynamic (PDT) procedures, but no long-term clinical trials have evaluated its effectiveness [source: AcneNet]. Nevertheless, research outcomes have been mostly positive. For instance, a 2003 study on high-intensity, narrow-wavelength blue light therapy resulted in a 59 to 67 percent reduction of acne lesions after eight treatments [source: Elman, Slatkine and Harth]. Similarly, a Japanese study of PDT in 2002 found a 64 percent acne reduction among participants, although 20 percent of the patients either didn't react to the light exposure or experienced aggravated acne symptoms [source: Kawada et al.].

Research data has also pinpointed minimal potential side effects from PDT treatments. In testing, the most common adverse reactions include skin dryness and flakiness, swelling and temporary skin sensitivity to light. PDT also isn't suited for every type of acne; blue light PDT may actually worsen nodulocystic lesions, which is a severe form of acne [source: AcneNet].

While acne patients may benefit from PDT, dermatologists generally don't consider it a first line of defense, especially since the skin blemishes will return after a period of time if left untreated [source: Kauffman]. The short blue light wavelength is gentler on the skin than ultraviolet rays, but it doesn't penetrate the sebaceous glands deep enough to eradicate P. acne bacteria completely. With current PDT treatments, the results may last up to six months. Consequently, dermatologists may prescribe PDT for patients with severe acne along with topical or oral medications.

In addition, patients who wish to undergo PDT probably won't get any financial help from their insurance companies. Aetna Insurance, for instance, refers to PDT and laser therapies as "experimental and investigational" because most branded PDT products haven't had to meet rigorous FDA approvals [source: Aetna]. Since the new technology typically isn't covered by insurance plans, acne patients should be prepared to pay between $550 and $800 per treatment session [source: DermaNetwork].

To learn more about preventing and treating acne, head over to the links below.

Related HowStuffWorks Articles


  • AcneNet. "Are laser and light treatments really light years ahead of conventional acne therapy?" American Academy of Dermatology. (Jan. 7, 2010)
  • Aetna. "Clinical Policy Bulletin: Phototherapy for Acne." Reviewed Nov. 6, 2009. (Jan. 10, 2010)
  • DermaNetwork. "Photodynamic Therapy." (Jan. 10, 2010)
  • Elman, Monica; Slatkine, Michael and Harth, Yoram. "The effective treatment of acne vulgaris by a high-intensity, narrow band 405-420nm light source." Journal of Cosmetic and Laser Therapy. 2003. (Jan. 10, 2010)
  • Hampton, Tracy. "Isotretinoin Regulations." Journal of the American Medical Association. March 22, 2006. (Jan. 10, 2010)
  • Kaufman, Joely. "Acne Therapy: How far have we really come?" Cosmetic Dermatology. October 2009.
  • Kawada, A. et al. "Acne phototherapy with a high-intensity, enhanced, narrow-banded, blue light source: an open study and in vitro investigation." Journal of Dermatological Science. Nov. 30, 2002. (Jan. 10, 2010)
  • Melville, Nancy. "PDT: Effective for Acne." Dermatology Times. November 2006.
  • Rohrer, Thomas E. "Lasers, Light Sources Battling Acne." Dermatology Times. June 2006.

More to Explore