Diode lasers for hair removal were cleared by FDA to market in the U.S. in 1997. This laser is often called "promising," but there is almost no published clinical data.
Published data overview:
As with other types, this laser has been shown to be useful in treating ingrown eyelashes. [A, B]
Observers of patient photos in one study felt 60% had sparse regrowth at 9 months (the rest had more), and 30% had temporary skin color change. [1] Another observed about 90% of subjects had reduction in color and diameter at 9 or 12 months, which compared favorably to ruby. [2]
The first published study observed less than 5% to 13% reduction at 8 months. [3] A short-term study study observed 34% reduction at 3 months. [4] A longer study observed between 53% and 34% reduction at 6 months and about 20 months. [5]
Unpublished data overview:
Unpublished data showed a growth delay of 1-3 months. They observed 11% had no permanent result, and 16 to 42% reduction at 9 months. Biopsies suggested miniaturization of regrowing terminal hairs into fine vellus hairs, which were observed to be an average of 20% thinner in diameter. 20% of patients had skin color changes lasting 1 to 3 months. 38% of patients were observed to have 26-47% reduction at 12 months. [6] Another unpublished study suggests super-long pulse might be safer on darker skin types. [7]
One unpublished report on 125 patients found 112 averaged 60% reduction following two treatments. One in five patients averaged 60% reduction at over 6 months. [adrian]
Side effects
There’s also a published report of a severe skin reaction similar to hives (urticaria vasculitis) following treatment. [8] Two small published studies suggest usefulness in treating "shaving bumps" (pseudofolliculitis barbae). [9,10]
References
= recommended only for in-depth researchers = may be worth ordering = strongly recommended
A. Oguz (1999):
B. Strempel (2000):
1. Campos (2000)
2. Lin (2000):
3. Williams (1999):
4. Baugh WP, Trafeli JP, Barnette DJ Jr, Ross EV. Hair reduction using a scanning 800 nm diode laser. Dermatologic Surgery. 2001 Apr;27(4):358-64.
5. Lou WW, Quintana AT, Geronemus RG, Grossman MC. Prospective study of hair reduction by diode laser (800 nm) with long-term follow-up. Dermatologic Surgery. 2000 May;26(5):428-32
6. Dierickx (1999):
7. Battle EF, Anderson RR. Study of very long-pulsed (100 ms) high-powered diode laser for hair reduction on all skin types. (unpublished , undated)
8. Moreno-Arias GA, Tiffon T, Marti T, Camps-Fresneda A. Urticaria vasculitis induced by diode laser photo-epilation. Dermatologic Surgery. 2000 Nov;26(11):1082-3.
9. Greppi I. Diode laser hair removal of the black patient. Lasers in Surgery and Medicine. 2001;28(2):150-5.
10. Kauvar (2000):
Adrian (1999)
Chan (2000)
Eremia (2001)
Soden (2001)
Handrick (2001)
Yamauchi (1999)
Summary of data with links to abstracts
Human clinical studies
Williams (1999): 26 dark-haired subjects were treated once a month for four months. Hair reduction varied between 5% and 13%. At 8 months after final treatment, observed reduction was below 5-13%.
Lin (2000): 41 patients were treated and observed either 9 or 12 months after treatment. This study showed 3 non-responders and 38 subjects with hairs that had reduction in color and diameter compared to pretreatment measurements.
Lou (2000): 50 ideal patients (light skin, dark hair) were treated and observed at 6 and ~20 months after treatment. Hair reduction varied between 53% and 34%.
Campos (2000): 38 subjects had 1 to 4 treatments. Observers comparing photos from before and an average of 9 months after treatment noted that 23 of the patients had sparse regrowth, while the other 15 had more regrowth. Eleven patients (mostly darker skin types) had temporary skin color change.
Kauvar (2000): 10 patients with pseudofolliculitis had 3 treatments at 6-8 week intervals all had better than 50% reduction in hair density and ingrown papule formation 6-8 weeks after last treatment.
Greppi (2001): 8 Black patients with pseudofolliculitis had resolution of the condition and hair reduction following treatment.
Side effects
Moreno-Arias (2000): Reports on a severe skin reaction similar to hives (urticaria vasculitis) following diode laser hair removal.
Eyelash (trichiasis)
Oguz (1999): 22 Turkish patients were treated successfully for ingrown eyelashes in 2 to 4 sessions.
Strempel (2000): 19 eyes treated saw improvement for itchy eyelashes.
Unpublished data
Grossman (1998): An abstract on a clinical study by the authors of Lou (2000)
Dierickx (1999): 92 ideal laser subjects saw growth delay of 1-3 months following one or two treatments at varying energy levels. Eleven percent had no permanent response. Average reduction at 9 months after treatment was fluenece dependent and and ranged from 16-42%. Biopsies suggested miniaturization of regrowing terminal hairs into fine vellus hairs, which were observed to be an average of 20% thinner in diameter. 20% of patients had skin color changes lasting 1 to 3 months. Of the 92, observation of 35 extraordinary results at month 12 ranged from 26-47% reduction of terminal hairs, or 3 to 5 times better than the results in the published Williams study, above.
2. Lin TY, and others. Reduction of regrowing hair shaft size and pigmentation after ruby and diode laser treatment. Archives of Dermatological Research 2000 Feb-Mar;292(2-3):60-7.
3. Williams RM, Gladstone HB, Moy RL. Hair removal using an 810 nm gallium aluminum arsenide semiconductor diode laser: A preliminary study. Dermatologic Surgery. 1999 Dec;25(12):935-7.
4. Baugh WP, Trafeli JP, Barnette DJ Jr, Ross EV. Hair reduction using a scanning 800 nm diode laser. Dermatologic Surgery. 2001 Apr;27(4):358-64.
5. Lou WW, Quintana AT, Geronemus RG, Grossman MC. Prospective study of hair reduction by diode laser (800 nm) with long-term follow-up. Dermatologic Surgery. 2000 May;26(5):428-32
6. Dierickx CC, Anderson RR, Campos VB, Grossman MC. Effective, permanent hair reduction using a pulsed, high-power diode laser. (unpublished , undated)
7. Battle EF, Anderson RR. Study of very long-pulsed (100 ms) high-powered diode laser for hair reduction on all skin types. (unpublished , undated)
8. Moreno-Arias GA, Tiffon T, Marti T, Camps-Fresneda A. Urticaria vasculitis induced by diode laser photo-epilation. Dermatologic Surgery. 2000 Nov;26(11):1082-3.
9. Greppi I. Diode laser hair removal of the black patient. Lasers in Surgery and Medicine. 2001;28(2):150-5.
10. Kauvar AN. Treatment of pseudofolliculitis with a pulsed infrared laser. Archives of Dermatology. 2000 Nov;136(11):1343-6.
