@Judee Glad it helps. The main effect of Huperzine A is to increase available acetylcholine. My neurologist researched it after I was unable to get compounded pyridostigmine, and suggested I try 200 mg a day, which is the typical dose used for Alzheimer's patients. I think most of the supplements out there come in this dose. Have you maybe tried taking a 100 mg a day?
I have been on it for about 18 months, and haven't had any experience with buildup. I also take
Benadryl for mast cells, which can reduce acetylcholine, so I think I have a decent balance. Maybe you just need a little less. Or maybe something else is out of balance.
I have hyper POTS with high blood pressure and have not found Huperzine A to be a vasconstrictor.