Single blind, randomized, controlled trial of a lightening product with and without iontophoresis versus tretinoin and vehicle for hyperpigmentation.

Background: Hyperpigmentation is a common concern and has many causes including lentigines and melasma. Currently available topical products for hyperpigmentation are limited by their potential for irritation, lack of demonstrated efficacy or regulatory concerns.
Objective: To compare the efficacy of a new skin lightening product with and without iontophoresis to a known effective product (tretinoin) and placebo on hyperpigmentation caused by lentigines and/or melasma. Secondary objectives included an assessment of the product's effects on the appearance of rhytides and roughness.
Methods and Materials: Eighty subjects were randomized into one of four treatment groups: proprietary lightening product, proprietary lightening product with iontophoresis, tretinoin 0.05% cream, or vehicle control. Seventy-four subjects completed all study visits. Blinded assessments of subjects were performed at each visit under ambient and Wood's light.
Results: The proprietary skin lightening product improved facial hyperpigmentation versus placebo under ambient light (P= 0.05) and Wood's lamp (P= 0.01) examination. Tretinoin also improved facial hyperpigmentation versus placebo under Wood's lamp (P= 0.01). The proprietary product was better tolerated than tretinoin, with fewer subject reported side effects.
Conclusion: The investigational product was effective and may be better tolerated than tretinoin cream.