Clinical trials for acne products are usually done for three months when evaluating effectiveness. However, benefits are often seen in four to six weeks. The reason for the delay is that acne lesions from under the skin take many weeks to surface. Some people can even have temporary breakouts early in the treatment and can be discouraged. You will see a clear and radiant complexion if you treat consistently.
However, if your skin does not look better after eight weeks, you may have a different type of acne called cystic acne which can cause scarring and may need more aggressive treatment by a local dermatologist.