如果你的肝脏没有损害的话,几个星期能看出来了。
Brand Name
Vitamin A Acid
Common Name
tretinoin (acne)
Tretinoin is used to treat certain types of acne. Tretinoin helps acne by causing the skin's outer layer to grow more quickly and be replaced with new skin cells, which helps to reduce the formation of blackheads, whiteheads, and other acne lesions. It may take up to 2 to 4 weeks to see improvement in your acne and the full effect of this medication may not be seen until 6 to 12 weeks.