Hi, thanks for asking in Healthcare Magic. Acne occurs commonly in young persons. It can occur due to androgenic (hormonal) stimulation of the sebaceous glands of face. Bacterial infection of the sebaceous glands results in inflammation and pus formation. YAZ is a oral contraceptive pill containing the progesterone Drospirenone and the estrogen, Ethinyl Estradiol. It is effective in hormonal based acne. Doxitab is Doxycycline. The bacteria (Propionibacterium acnes) responsible for acne is sensitive to Doxycycline. Though hypersensitivity (allergic) reactions are uncommon with Doxytab, skin rashes have been reported. Also it frequently results in sunburn - like skin reaction on the exposed parts like face (photo toxicity) in sensitive individuals. Long term administration of Doxycycline can result in serious side effects and hence is not advisible. Since you have mentioned that acne leaves marks, Retinoic acid (Tretinoin) cream will be very effective for you. Tretinoin inhibits the occurence of excessive pigmentation or black spots of skin due to acne. The pigmented spots tend to fade after Tretinoin application. Adapalene cream is a better alternative. I hope this is useful.