Retin-A Microsphere Gel is a great product that effectively treats acne vulgaris. This product is prepared with a unique formulation and contains 0.1% or 0.04% different strengths. It starts working on the skin with its very first day of use. It significantly reduces the severity of acne and quickly heals the pain. Tretinoin is a class of drug and is used as the main ingredient in Retino-A Microsphere Gel.