I posted this info on "The Marriage Bed" website. Here's the only response I got. I don't know enough about this to respond.
"Some of the information on those sites can be pretty misleading, or even ignorrant.
ACh is probably the most common neurotransmitter in the human body. Certainly, it is involved in sexual functions, but it is part of just about every other bodily function. It is quite literally involved at every level, both neuron to neuron, or neuron to muscle cell. I think it would be unlikely to find anyone who is deficient in any way, that still had muscle control to walk, sign their name, etc.
I would be very cautious in trying to alter anything in the CNS. Simple fact of the matter is that enough is just right, and more than enough can create issues. If you can walk, chew gum, etc, then you already have the right amount of ACh.
This is not one of those "more is better" things."