Evaluation of the herpes simplex virus antiviral activity of pyrethrins.

Pyrethrins, complex esters extracted from Chrysanthemum cinerariaefolium, exhibit only minimal in vitro activity against herpes simplex virus (HSV). Employing a guinea pig model of HSV genital infection, no in vivo activity could be demonstrated. Although purported to be an effective remedy for the treatment of genital herpes, we were unable to demonstrate efficacy for either the oral administration of an alcoholic solution of pyrethrins or the topical application of pyrethrins in mineral oil.