What are the effective medications for acne without any side effects?

Hi doctor,

I am a 20-year-old female. I have had acne on my face, back, and chest since three years ago. A month ago, I treated them with Doxycycline 100 mg, but I have gained weight. About eight months ago, I went to a dermatologist, and he gave me Azithromycin 250 mg. It made my face clear without acne in a few weeks, and I had great results, but its side effects were tachycardia and a high heart pump, so I stopped. One month ago, I went to the dermatologist again, and he prescribed me Doxycycline 100 mg with dinner. It gave me good results with my acne, but the main issue is that I started to gain weight, 5 kg in one month, without any changes in diet and exercise. So, for two days, I stopped the drug, but I want to really find solutions for my acne without dangerous side effects. Please help.