###Human: How can oily scalp and face be treated? ###Assistant: Hello. What you have told is correct. To prevent relapse of acne one needs to complete a total dose of 120 mg/kg of Isotretinoin. As your weight is 55 kg you should be taking a total of 6600 mg of Isotretinoin to prevent relapse. That comes out to be 330 days of 20 mg per day of Isotretinoin. That is almost 11 months of 20 mg Isotretinoin. This dose is recommended to prevent relapse of acne.