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.