Hi! I totally understand how frustrating relapsing is. My acne started to relapse after only 2 months off of Accutane. As for the dosage, I would ask your dermatologist for sure. They will know how much to give you based on not only your new weight but how you want to approach this round (e.g. fast and aggressive or  less aggressive over a longer period of time). I hope you have a successful second round!

Did your doctor check for microscopic demodex skin mites? They can cause acne like lesions that frequently get misdiagnosed. It happened to me, for decades. The mites eat skin oil. Since Accutane drastically reduces the output of skin oil, it can starve the mite population down. But Accutane isn't anti-parasitic so once you are off the Accutane, the mite population can rebound. There are 2 kinds of human demodex. Demodex Brevis live down in the oil glands. Demodex Folliculorum live in the follicles. When the mites die off they make pustules, papules and cysts. The mites live and die on a 2 to 3 week life cycle which may make the acne appear cyclical. Because of the cyclical nature, it frequently gets misdiagnosed as hormonal acne. Demodex can live anywhere on the body that there is an oil gland - everywhere but on the soles of the feet and palms of the hands.

Symptoms include: large blackeads, pustules, papules, red cysts, red irritated eyes, styes on eye lids, scalp acne, body acne, occular rosacea (blepharitis demodex). You may have some or all of these symptoms.

There is a 2 week, highly effective, cheap, 2 drug oral, anti-parasitic treatment for demodex. It was published in the May 2013 International Journal of Infectious Diseases by 5 doctors. It is a proper medical study on 120 patients. Treatment consists of taking 2 generic anti-parasitic drugs: Once weekly dose of Oral Ivermectin (dosage based on body weight at 200 micrograms per kilogram of body weight) and Oral Metronidazole at 250 mg 3 times a day (with food, no alcohol while taking or for 72 hours after last table). Both drugs have good safety records and are on the WHO's list of 100 essential medications.

Here's a link to the medical paper entitled "Evaluation of the efficacy of oral ivermectin in comparison with ivermectinmetronidazole combined therapy in the treatment of ocular and skin lesions ofDemodex folliculorum" URL: https://www.sciencedirect.com/science/article/pii/S120197121201315X

If the link is broken, Google the title of the paper to find it.

A knowledgeable dermatologist can test for demodex by collecting a skin sample, placing it on a microscope slide and trying to count the demodex under the microscope. Demodex mites do not like light so counting them under a microscope can be tricky. Since Demodex Brevis live in the oil glands, they can be trickier to diagnose. Some dermatologist will prescribe the treatment without the test to rule out demodex as the source of the problem.

The anti-parasitic treatment will only work if the skin issues are caused by demodex skin mites. They should also test for a fungal or bacterial infection and possible elevated hormones including thyroid. Treatment for each of these conditions is completely different. Identifyingthe source of the problem is key to curing it with the right treatment.