Dr. Howard Sobel has been a practicing New York City dermatologist and dermatologic cosmetic surgeon for more than 25 years, combining modern technology with cosmetic skin care. In 1991, Dr. Sobel was among the first to pioneer the union of cosmetic dermatology and topical skin care when he founded HDS Cosmetic Lab, a line of skin-care products that delivered excellent results without a prescription. In 1995, the name was changed to DDF (Doctor's Dermatologic Formula) to help define the brand as a doctor's dermatologic line. DDF developed its legendary mantra — Cleanse. Protect. Treat. — focusing on anti-aging (preventative and restorative), acne, hyperpigmentation, rosacea, sun protection, and sensitive-allergic conditions.