1996 · Grossman, Dierickx, Anderson (Massachusetts General Hospital)
Ruby laser
Wavelength. 694 nm
The first laser studied for hair removal. In 1996, 13 volunteers with brown or black hair were treated with normal-mode ruby pulses of 30 to 60 J/cm2. The FDA cleared the EpiLaser normal-mode ruby laser on 5 March 1997 and the Sharplan ruby laser on 7 March 1997.[1][2][3]
Suits. Fair skin with dark hair. In 51 patients followed a mean of 8.4 months, 63% had sparse regrowth.
Trade-offs. Strong melanin absorption raises the risk in darker skin: pigment changes were most frequent in skin type IV. A 2006 Cochrane review found little randomized evidence for the ruby laser.
2000 · Long-pulse devices; studies by Garcia, Gorgu and others
Alexandrite laser
Wavelength. 755 nm
A long-pulse laser with high melanin absorption. In 12 patients treated on one armpit with alexandrite and the other with electrolysis, clearance at 6 months was 74% with the laser and 35% with electrolysis.[1][2][3]
Suits. Light to medium skin with dark hair. A 2006 Cochrane review found about 50% short-term hair reduction up to 6 months with alexandrite and diode lasers. In 150 patients with skin types IV to VI, complications occurred in 2%.
Trade-offs. Facial paradoxical hypertrichosis followed alexandrite treatment in 16.2% of women in a 2025 prospective study. In a 7,381-patient series, 24 of 25 cases of paradoxical growth followed alexandrite treatment.
1999 · Star Medical Technologies (LightSheer); Campos, Dierickx, Anderson
Diode laser
Wavelength. 800 to 810 nm
A semiconductor laser. The FDA cleared the LightSheer pulsed diode array on 8 April 1999. In a 2000 study of 38 subjects, 59% had only sparse regrowth at a mean 8.7 months after 1 to 4 treatments.[1][2][3]
Suits. Most skin types, with longer pulses for dark skin. LightSheer pulses of 30 and 100 ms were used safely in African American patients with skin types V and VI. A large-spot vacuum diode cleared 54% of armpit hair at 6 months and 42% at 15 months after 3 sessions.
Trade-offs. Transient pigment changes followed 29% of treatments in the 2000 study and were more common in skin types IV to VI.
2001 · Alster, Bryan, Williams; Tanzi and Alster
Long-pulsed Nd:YAG laser
Wavelength. 1064 nm
An infrared laser with the longest wavelength of the hair removal lasers. In 20 women with skin types IV to VI, 3 monthly treatments gave 70% to 90% hair reduction 12 months after the last session.[1][2][3]
Suits. Dark skin. A 2013 review calls it the best laser for pigmented skin, and a 2026 review calls it the standard for laser hair removal in skin types IV to VI.
Trade-offs. Less effective than shorter wavelengths in some reviews. In 36 patients of all skin types, hair reduction fell from 58% to 69% at 1 month to 41% to 53% at 6 months.
1997 · ESC Medical Systems (EpiLight); Gold and colleagues
Intense pulsed light (IPL)
Wavelength. Broad spectrum, about 590 to 1200 nm
A filtered flashlamp, not a laser, that emits a broad band of light. The FDA cleared the EpiLight Hair Removal System on 7 July 1997. A single EpiLight treatment removed about 60% of hair at 12 weeks in 37 subjects.[1][2][3]
Suits. Light skin with dark hair. In 24 patients examined 1 year after one session, hair removal was 75%. With 2 treatments in skin types I to V, hair counts fell 33% at 6 months.
Trade-offs. A 2006 Cochrane review found little randomized evidence for IPL. A 2026 review advises against IPL in skin types IV to VI because of hyper- and hypopigmentation.
1997 · Nanni and Alster
Q-switched Nd:YAG with carbon lotion
Wavelength. 1064 nm, nanosecond pulses
An early method. The skin was waxed and coated with a carbon solution that entered the empty follicles, then treated with very short pulses. It delayed regrowth: full regrowth was seen at all sites by month 6.[1][2]
Suits. Temporary hair delay. In an armpit comparison, it reduced regrowth 27% at 3 months against 19% for one alexandrite treatment, with lower pain scores (4 against 8).
Trade-offs. Not a long-term method. Long-pulsed lasers are used for hair removal instead.
2009 · Spectragenics (TRIA) and other makers
At-home lasers and IPL
Wavelength. Low-fluence diode laser (800 to 810 nm) or IPL
Small devices sold over the counter for self-treatment. The FDA cleared the TRIA diode laser on 23 December 2009 for use with shaving and for permanent reduction in hair regrowth. A 2012 systematic review found 7 studies, none randomized, with hair reduction of 6% to 72%.[1][2][3]
Suits. Self-treatment at home. In a 2015 randomized trial of 36 women with skin types I to IV, 8 weekly 810 nm home treatments cut growing hair up to 59%.
Trade-offs. Results depend on continued use. In that trial, growing hair counts were 29% above baseline 3 months after treatment stopped. Erythema was the most frequent side effect in the 2012 review.
1875 · Needle-type epilators; Richards and Meharg
Electrolysis (for comparison)
Wavelength. Needle in each follicle, electric current
A fine needle is placed in each follicle and current destroys the hair-producing cells. It has been performed since 1875. Florida law defines electrolysis as the permanent removal of hair by destroying the hair-producing cells.[1][2][3]
Suits. Small areas. Before lasers, it was the only method that offered permanent removal. A 1995 report covers 140,000 hours of electrolysis practice.
Trade-offs. Slow: one hair at a time. In a split-armpit trial, the alexandrite laser was 60 times faster and cleared 74% of hair against 35% for electrolysis.