Lion's Mane Extract

In a 16-week, double-blind, placebo-controlled trial of 30 Japanese adults aged 50 to 80 with mild cognitive impairment, those taking 3 g/day of Hericium erinaceus (Yamabushitake) dry fruiting-body powder scored significantly higher on a cognitive rating scale than the placebo group at weeks 8, 12 and 16. Scores declined significantly after stopping treatment, and no adverse laboratory findings were reported. These results do not prove a durable effect, establish equivalence of different extracts or preparations, or apply to young or healthy adults.^[1]

• Small study of a specific dry-powder preparation; no inference to all extracts, young adults or dementia prevention.
• A separate small pilot trial in healthy young adults using a different (mycelium-based capsule) preparation and lower dose found mixed positive, null and negative results rather than the pattern seen in this older, cognitively-impaired population (see the companion young-adults finding for this compound).
• Abstract-checked; no qualified clinical review.

A separate small pilot trial randomized 41-43 healthy adults aged 18 to 45 to 1.8 g/day Hericium erinaceus or placebo. A single dose improved speed on one attention test (the Stroop task) at 60 minutes, and 28 days of use showed a non-significant trend toward lower subjective stress on one of two stress scales used. The same trial also found significantly fewer correct immediate word-recall responses after a single dose, and significantly better delayed word recall in the placebo group after 28 days. The authors describe these as preliminary, mixed findings in healthy young adults, not a confirmed cognitive or mood benefit.^[2]

• Small pilot (n=41-43) with many statistical comparisons and no stated correction for multiplicity; positive, null and negative findings across different tasks should not be reduced to an overall benefit claim.
• Uses a different preparation (mycelium-derived capsule, lower daily dose) than the dry fruiting-body powder studied in the primary Hericium erinaceus claim for this compound, in a different (healthy, young) population; the two findings are not directly comparable.
• Passage-checked in full text (PMC Open Access, CC BY); no qualified clinical review.