Dr. Kligman had been on the faculty of prestigious University of Pennsylvania for 50 years.
A prolific researcher, Dr. Kligan was first to describe the human hair-growth cycle (interesting information for those of us who need waxing), investigated the pathogenesis of acne vulgaris, identified the effects of sunlight on the skin (that's how we know the bad things sun does to our skin), and coined the terms photoaging and cosmeceuticals. He also disproved that chocolate promotes acne and other myths.
Tretinoin (Retin-A) is a derivative of vitamin A and originally was too aggressive for the skin until Dr. Kligan refined it. He patented it in 1967. Along the way he discovered the tretinoin reduced wrinkles - thus we have Renova.
Rest in peace Dr. Kligan, we'll miss your discoveries.
