Photoepilation with a diode laser vs. intense pulsed light: a randomized, intrapatient left-to-right trial.

BACKGROUND: Safe and efficient options for removing unwanted hair are in great demand. Laser devices and intense pulsed light (IPL) sources are the most commonly used treatment modalities. Yet, only a few randomized controlled trials (RCTs) comparing laser and IPL devices are available, and RCTs with long-term results are missing from the literature.

OBJECTIVES: To compare the safety and long-term efficacy of diode lasers (DL) and IPL sources for axillary hair removal, we conducted an intrapatient, left-to-right, assessor-blinded and controlled trial.

METHODS: IPL (Ellipse Flex PPT; Danish Dermatological Development, Hoersholm, Denmark; λem=600-950 nm) and DL (LightSheer XC system; Lumenis Inc., Santa Clara, CA, U.S.A.; λem=800 nm) treatments were evaluated in 30 study participants (skin type II-III) with unwanted axillary hair growth. Six treatments with each device were carried out at 4-week intervals. Final assessment was conducted 12 months after the last treatment by means of hair counts using close-up photographs. The primary endpoint was reduction in hair growth, analysed on an intention-to-treat and last-observation-carried-forward basis (n=30), and secondary endpoints were patient-rated efficacy, treatment-related pain, adverse effects and treatment duration.

RESULTS: Both devices significantly reduced hair counts. Mean reductions from baseline (3 and 12 months after the last treatment) were 59·7% and 69·2% for DL and 42·4% and 52·7% for IPL treatment (P<0·01), respectively. DL treatment induced significantly more pain [3·7±2·1 (DL) vs. 1·6±1·4 (IPL); P<0·01; visual analogue scale] but could be conducted faster [33·1±3·8 s (DL) vs. 40·1±5·0 s (IPL); P<0·01]. No severe side-effects were observed for either therapy.

CONCLUSIONS: Both DL and IPL treatments are highly effective, long lasting and safe. DL was found to be more effective than IPL treatment. DL treatment was more painful but less time-consuming than IPL therapy.