I previously took accutane 3 years ago and my acne is back. i am 55kg and was on 20mg/day for 8mnths. will i still need same dosage as i did before?

We'll see: You may need a slightly lesser dose. One thing to think about is whether you, a young woman, have a little more androgen on board than the next lady, and if so why that might me & whether it's something you'd want to address (it's your chemistry & your choice). Hope you're staying physically fit -- this can help balance the perplexing hormonal milieu. Glad your acne was rx'd effectively, good luck.

Accutane: The most effective Accutane therapy is 1mg per kg. Thus, the most effective therapy for you is 60mg per day for 6-7 months.