Huperzine A acts to increase the levels of the neurotransmitter acetylcholine in the brain and peripheral nervous system. As such, it is thought to be able to improve memory, alertness, focus, mood, and cognitive functions. It is commonly used by students and others looking for a natural nootropic agent with cholinergic activity to give them that mental edge at school and at work.
In the central nervous system, cholinergic neurons project from the basal forebrain to the cerebral cortex and the hippocampus. These networks are thought to play vital supportive roles in cognitive functioning. In addition, the hippocampus is well-known to be essential in transforming short-term memories into long-term memories and acetylcholine is vital for this process. Individuals with dementia tend to suffer from great difficulty in transforming short-term memories into long-term memories and some patients with early forms of dementia take huperzine A in an effort to improve this process. The transformation of short-term memory to long-term memory is also essential for students and others attempting to rapidly memorize large amounts of material, and huperzine A is believed to improve the efficacy of learning.
In addition, acetylcholine is used by the autonomic nervous system to enact its stimulatory functions throughout the body via the parasympathetic nervous system, and huperzine A’s ability to activate the parasympathetic nervous system is thought to play a role in enhancing focus and energy levels, and activation of this system is also the primary cause of huperzine A’s side effects (see below).
Huperzine A mediates its effects by blocking the breakdown of acetylcholine by the enzyme acetylcholinesterase. It binds directly to acetylcholinesterase and prevents it from functioning in a reversible fashion. Orally consumed huperzine A has been shown to readily enter the body via the digestive tract and is able to cross the blood-brain barrier, where it diffuses throughout the brain and causes a global increase in acetylcholine levels. Outside the brain, in the peripheral nervous system, it acts in the same way.