Topical Cyperus rotundus essential oil for treatment of axillary hyperpigmentation: a randomized, double‐blind, active‐ and placebo‐controlled study

Summary Background The oil of the grass Cyperus rotundus (purple nutsedge) is an effective and safe treatment option for a variety of conditions. It has anti‐inflammatory and antipigmenting properties. There have been no clinical trials comparing topical C. rotundus oil with skin‐lightening treatments for axillary hyperpigmentation. Aim To assess the efficacy of C. rotundus essential oil (CREO) in treating axillary hyperpigmentation, and compare with another active treatment hydroquinone (HQ) and a placebo (cold cream) in this study. Methods The study included 153 participants, who were assigned to one of three study groups: CREO, HQ group or placebo group. A tri‐stimulus colorimeter was used to assess pigmentation and erythema. Two independent experts completed the Physician Global Assessment, and the patients completed a self‐assessment questionnaire. Results CREO had significantly (P < 0.001) better depigmenting effects than HQ. CREO and HQ did not differ significantly in terms of depigmentation effects (P > 0.05); however, there were statistically significant differences in anti‐inflammatory effects and decrease in hair growth (P < 0.05) in favour of CREO. Conclusions CREO is a cost‐effective and safe treatment for axillary hyperpigmentation.