Hydroquinone is the prototypical “bleaching cream,” although in reality, it does  not actually bleach the skin. Instead, it prevents pigment synthesis by inhibiting  the enzyme tyrosinase in melanin producing cells. Hydroquinone is most effective when combined with a topical steroid and a retinoid, which is commercially  available as a prescription.   Craig Singer MD Dermatology sells a triple therapy bleaching cream that combines all three active ingredients with the additional  benefit of the antioxidant vitamin C and niacinamide. We have found that most  patients respond favorably to this combination therapy. Initial response is usually  seen in the first 4 to 6 weeks after initiation of triple therapy bleaching cream and  may continue to improve over the next several months. Although irritation is  sometimes seen in the beginning, most patients can tolerate daily use.   Our triple therapy bleaching cream has a milder strength a retinoid which improves  tolerability.  In the past, hydroquinone was restricted to three months. However, we have  recently noted that hydroquinone at standard concentrations may be used  continuously for up to six months as long as the patient is being monitored by a  physician.