Hello. Thank you for writing to us The drug that you inquire about is an oral retinoid, Isotretinoin. Isotretinoin is an excellent drug for severe grade of acne Or acne that does not respond adequately to traditional antiacne treatments. However, Isotretinoin has no effect whatsoever on acne scars. Acne scars, can be improved cosmetically with various other measures like chemical peeling, microdermabrasion, microneedling, fractional Co 2 Laser etc. I suggest that you discuss about these various techniques and the best one to reduce acne scaring with your dermatologist. Isotretinoin is a vitamin A derivative and also gets stored in lipid rich tissues like adipose tissue from where it gets slowly liberated into blood. Its elimination half life is 21-28 days after stopping oral intake. Therefore skipping a dose for a short duration like 2- 3 days is not going to alter serum levels by much, however, it is always advisable to continue this oral treatment regularly till the entire duration of treatment. Regards