I recently came across an interesting study on the effects of acute cholinesterase inhibitors (huperzine-A and galantamine) in healthy adults (18-38 years).
Doses used for huperzine were 100mcg and 200mcg.
Doses used for galantamine were 4mg and 8mg.
As for the results:
What does everyone think about this study? Do you think that AChE inhibitors are viable nootropics in healthy non-elderly adults? Perhaps only during times of sleep deprivation (other AChE inhibitors have been found to have pro-cognitive effects in healthy young adults only during times of sleep deprivation in subjects who were "behaviorally vulnerable to sleep loss")? Or perhaps as an addition to a nootropic stack (likely containing a choline source)?
Doses used for huperzine were 100mcg and 200mcg.
Doses used for galantamine were 4mg and 8mg.
As for the results:
So it appears that both huperzine and galantamine are effective AChE inhibitors in healthy non-elderly adults, which is nice, but:Huperzine 100 μg reached peak AChE-inhibiting activity (83% of pre-drug activity) 90 min following administration...
Huperzine-200 μg reached maximal AChE-inhibiting activity 30 min post-dose (72% of pre-drug activity)...
Thereafter (starting at 150 min post-dose), both Hup-100 and Hup-200 maintained similar levels of AChE-inhibiting activity across subsequent sessions...
Galantamine also dose-dependently inhibited AChE activity...
Gal-4 reached peak inhibition (85% of pre-drug activity) at 150 min post-dose...
Gal-8 reached peak inhibition at 210 min post-dose (75% of pre-drug activity)...
With the exception of the 1330 h [3.5 h post-dose] sampling session, AChE activity in both galantamine doses was similarly inhibited... and significantly lower than Pla across all other post-drug sessions...
Despite rapid inhibition of RBC AChE (and a presumed increase in central cholinergic activity), neither huperzine A nor galantamine impacted neurobehavioral performance.
Physiological and neurobehavioral effects of cholinesterase inhibition in healthy adults. - PubMed - NCBIThe lack of neurobehavioral efficacy in this study was not entirely unexpected. Our subjects consisted of healthy, non-sleep-deprived young adults. In addition, although practice effects were evident on some tasks (discussed next), in general, performance levels on all tasks were high...
Results from prior studies indicating pro-cognitive effects, taken together with our findings, indicate that in otherwise normal, healthy adults with intact central cholinergic functioning, AChE-inhibiting compounds do not exert cognition-enhancing effects. Also, the results presented here indicate that these compounds do not interfere with the normally high levels of neurobehavioral functioning seen in this cohort...
What does everyone think about this study? Do you think that AChE inhibitors are viable nootropics in healthy non-elderly adults? Perhaps only during times of sleep deprivation (other AChE inhibitors have been found to have pro-cognitive effects in healthy young adults only during times of sleep deprivation in subjects who were "behaviorally vulnerable to sleep loss")? Or perhaps as an addition to a nootropic stack (likely containing a choline source)?