Rdl contains tretinoin and hydroquinone. Tret helps renew the skin while hydroqui quickly fades skin blemishes. Pero tret + hydro in a single product can be a very dangerous combination for your skin if you are not guided by a dermatologist.
Also heavy sunscreen is a must kung gagamit ka nito kasi your skin will become very sensitive to the sun na pwedeng magresult ng permanent side effects.
For example, this is a result ng maling paggamit ng hydro