Assuming no underlying health conditions, damn near anything you can buy that’s labelled for human ingestion is fine occasionally. Even stuff like caffeine that’s somewhat addictive, if you actually make it an occasional thing, it isn’t a big deal. Hell, if you have the sense to keep it to very rare occasions, tobacco isn’t anything to worry about, even when smoked. It isn’t good for you, but if it’s a thing where you only have a cigar on your birthday, it’s not doing anything your body can’t handle.

A monthly dose of energy drink? Well, it means your tastebuds are shot already, but that’s different issue lol. It won’t mess up your heart, digestion, or anything else as long as you don’t have an issue that would indicate otherwise.