I have run it as an AI during cycles. I don't have a set dosage or schedule. I'd take it every other day, every third day, every day for a few days. Basically I would take more and more frequently when I had pain in my nipples and reduce the dosage and frequency when I did not have any nipple pain. That's just what I do, it might be a bad way to run letro.
I've seen different advice such as keep it on hand and only run it if you experience gyno symptoms, run it automatically if your gyno prone, run it every other day at a low dose as a precaution and increase the dose if you experience symptoms of gyno...
Not sure how helpful that was. I guess I would advise you to research, research, research to learn as much as you can about AI's and letro in particular. You can never get too much info when it comes to steroid usage. There are tons of dudes in gyms pumping all sorts of steroids in their muscles and have no idea what PCT is or what an AI is.....