Huperzine Rx-Brain works for me in less than an hour. VERY powerful and I have to take only half of the pill for 3 days in a raw, then make a break, for liver relief (it starts hurting). Then I can take it again and it really helps to use my mind, restore short term memory and improve my mood. Great product. I haven't found so far nothing better working than that, just be aware of the dosage.