Effect of a topical polyherbal formulation for premature ejaculation: A randomized triple-blind placebo-controlled trial

•Persian medicine as a complementary treatment discipline suggests different natural products for premature ejaculation.•A topical oil containing black cumin oil, olive oil and frankincense was evaluated as a randomized controlled trial.•The drug had no significant adverse effect.•There was no remarkable change in total IELT and PEDT scores.•The drug significantly improved premature ejaculation frequency and interpersonal difficulty items.