there’s not a lot of proper research on dose frequency like that unfortunately. a lot of people swear by Anne Shulgin’s 3 month rule, but that was simply her saying “i feel like this drug would be best enjoyed 4 times a year spaced out” after using it frequently. the clinical trials run by MAPS did 2 “experimental sessions” (the rolls) spaced 5-7 weeks apart, then stopping for a few months.
MDMA is pretty hard on your noggin and there’s no set guidelines. if you’re doing reasonable doses (a max of 250mg per roll), using vitamins and supplements to reduce the harm, sleeping/eating well, and otherwise taking care of yourself then you’re probably fine. if you’re using large amounts (anything over 250-300mg), it’s probably less fine. your brain needs time to recover between rolls and it’s very person to person. i’ve had times where i roll a couple times with only 2-3 weeks between, but ive always made sure to not make a habit of that and give it a rest after a couple rolls.
1 month between rolls isn’t too bad, at least on occasion. if you’re habitually rolling every month, it’s probably wise to take an extra month or two off every so often. you may not notice any side effects now but that doesn’t mean they won’t build up in the background and present themselves later. the more often you roll with just 1 month between the more likely you are to begin to notice side effects and lose the magic. 2-4 weeks between rolls isn’t a big deal if you don’t do it often. there’s no hard and fast rule but in my experience i’d advise taking a 2-3 month break every 3-4 rolls to fully give your brain time to catch back up.