Can using retin-a as little as once or twice a week still be effective?

unfortunately, i suffer with mild adult acne. in order to control my breakouts i use a skin care line called obaji, and on ocassion i take an oral antibiotic called minocyclin. when i take the antibiotic in phases it seems to work well. however, my skin begins to grow a tolerance and i am left having to find another source to shock my skin again. so, i often turn to retin-a. the only thing with retin-a is that it doesnt allow u to be in the sun very much. so i was wondering if i just used the it once or twice a week vs every day, would it still be as effective and solve the issue of not being able to enjoy some occasional sun?

Can using retin-a as little as once or twice a week still be effective?
I would recommend checking with a dr about this, especially to see if maybe a hormone imbalance could be playing in to the issue with your acne situation.