Generally, Asian ginseng seems to improve cognitive performance more than American ginseng, though the American form does still have cognitive enhancement potential.22 Korean red ginseng appears to improve concentration, scanning ability, and memory recall and is thought to stabilize the nervous system and decrease neuroinflammation.23 Ginseng also seems to be particularly potent when paired with ginkgo biloba, another nootropic botanical.24 However, a strict meta-analysis from 2010 could only identify five trials that met its stringent requirements for data reliability.102 Among those trials, there was a lack of convincing evidence to show a cognitive enhancing effect of Panax ginseng in healthy participants and no high-quality evidence about its efficacy in patients with dementia. Huperzine A Huperzia serrata (toothed clubmoss) produces a potent compound known as huperzine A

Preclinical studies suggest the peptide may promote mucosal healing, enhance tight junction integrity, and reduce intestinal permeability in animal models
Does Dihexa dosage need to increase over time to maintain effects
Yes, lyophilized (freeze-dried) vials do best refrigerated at 3646F (28C), tolerate cool room temperature for short periods, and last longest frozen at -20C (-4F) or colder