Photoepilation results of axillary hair in dark skinned patients by intense pulsed light: Comparison between different wavelengths and pulse width

Two groups of Korean women were treated with either an IPL 600-950 nm (HR applicator) or IPL 645-950 nm (HR-D applicator) and hair counts were measured. Both groups saw significant hair count reduction, but average clearances were much higher with the HR-D.

PubMed Reference:Hee Lee J, et al. Dermatol Surg. 2006 Feb;32:234-40.

Study Details:

  • 28 Korean women (mean age 28.7 years, range 21-47; skin types II-IV) treated with IPL 600-950 nm (HR applicator) to the axillary area
  • 27 Korean women (mean age 29.9 years, range 21-43; skin types III-IV) treated with IPL 645-950 nm (HR-D applicator) to the axillary area
  • 4 IPL treatments at 4- to 6-week intervals:
    • HR applicator: mean fluence 14.9±2.0 J/cm2and pulse duration of 40 ms (thick hair) and 20 ms (medium hair)
    • HR-D applicator: mean fluence 17.1±0.6 J/cm2and pulse duration of 50 ms (thick hair) and 25 ms (medium hair)
  • Hair counts of 1 cm2area performed by blinded investigator, using magnified 3x5 inch photographs

Study Results:

  • All subjects showed statistically significant (p<0.001) hair count reduction
  • Average clearances of 83.4% and 52.8% were achieved by HR-D and HR, respectively; HR-D results significantly higher (p<0.001)
  • Pain level significantly lower (p<0.05) with HR-D (3.3 vs. 6.5 out of 10)
  • No adverse effects with HR-D treatment
  • 1 case of perifollicular hyperpigmentation at 3rd treatment (subject discontinued) & 1 case of mild hypopigmentation at 2nd session (normal skin color at 9-month follow-up) with HR applicator
  • Using the HR-D applicator (at 645 nm) to filter out the shorter wavelengths absorbed by epidermal melanin and applying longer pulse durations resulted in higher hair reduction percentage, less discomfort and no adverse effects