Panax Ginseng — The Classic Adaptogen
Panax ginseng (Asian ginseng) is one of the most extensively studied herbal medicines, with over 5,000 published studies. Its active compounds — ginsenosides — have adaptogenic, neuroprotective, immunomodulatory, and metabolic effects. It is used for cognitive function, energy, sexual health, immune support, and blood sugar regulation.
Mechanism of Action
Ginsenosides (Rg1, Rb1, Rg3, Re, Rd) act on multiple targets: glucocorticoid receptors (adaptogenic), NMDA and nicotinic receptors (cognitive), eNOS (vascular), and insulin signalling (metabolic). They modulate HPA axis stress response, reduce cortisol, activate Nrf2, and inhibit NF-κB. Rg1 promotes neurogenesis; Rb1 has neuroprotective and anti-apoptotic effects.
Human Trial Evidence
A 2010 Cochrane review found evidence for improved cognitive performance in healthy volunteers. A 2014 Journal of Ginseng Research meta-analysis confirmed glycaemic control benefits. Multiple RCTs show improved fatigue, sexual function (erectile dysfunction), and immune function. Korean red ginseng (steamed) has higher ginsenoside bioavailability than white ginseng.
Dosing Protocol
200–400 mg/day of standardised extract (4–7% ginsenosides). Korean red ginseng: 1–3 g/day of root powder. Best taken in the morning (stimulating). Cycle use (8–12 weeks on, 2–4 weeks off) to prevent tolerance. Effects on cognition and energy typically seen within 4–8 weeks.
Safety & Contraindications
Generally well-tolerated. Insomnia, headache, GI effects possible. May lower blood glucose — caution with diabetes medications. Mild estrogenic effects — caution in hormone-sensitive conditions. Avoid with warfarin (reduces INR). Stimulant effects — avoid with other stimulants.