Currently on a fast and had wanted to explore microdosing but not sure if I should wait until afterwards. It would be one 200mg or 500mg cap.
Micro-dosing what? LSD? I don’t believe LSD has really any calorie value, much like asprin https://www.carbmanager.com/food-detail/md:297ccbde7e75c6b38fc91ed8991fd9fb/aspirin
Mushrooms absolutely have calories, and are usually a 3 to 1 carb to protein make-up.
You can always just test yourself by using ketostix before and after to monitor changes in your ketosis state. If there is no change, then it really doesn’t matter in terms of breaking a fast.