howtosupplement
Cognition

Huperzine-A

Acetylcholinesterase inhibitor from Chinese club moss that may improve cognitive symptoms in dementia; evidence in healthy adults is limited.

Huperzine-A

Huperzine-A

46
score
C
evidence
Caution
risk

Proven Benefits

01Improves cognition in dementia
02May improve memory in adults
03May support neuroprotection

Chemical Forms

Recommended
  • Huperzine-A (pure alkaloid)
  • Huperzia serrata extract (standardized)
Avoid
  • Generic Huperzia serrata powder (unknown alkaloid content)
Expert Note

Effective dosing depends on the huperzine-A alkaloid, typically 200 mcg. Non-standardized plant powders contain variable and often subtherapeutic levels of the active compound.

Protocol

Amount
200-400 mcg
Frequency
Once or twice daily
When
Morning and/or afternoon; avoid late evening due to potential insomnia from cholinergic stimulation.

Condition-Based Dosing

Alzheimer's disease or vascular dementia
200-400 mcg daily in divided doses
General cognitive support in healthy adults
200 mcg daily

Safety & Limits

Upper Safe Limit
400 mcg/day (highest studied chronic dose; no official UL established)
Cycling
Safe for continuous use

Contraindications

Bradycardia, heart block, or seizure disorders — cholinergic excess can worsen these
Pregnancy and breastfeeding — insufficient safety data
Concurrent use of donepezil, rivastigmine, or other AChE inhibitors — risk of cholinergic crisis
Asthma or COPD — may increase bronchial secretions and bronchoconstriction
Gastrointestinal ulcer disease — increased gastric acid may worsen ulcers

Synergies

Alpha-GPC

Choline donors provide substrate for acetylcholine synthesis, potentially complementing acetylcholinesterase inhibition.

Avoid Combining With

  • ✕Anticholinergic medications (counteract effects)
  • ✕Acetylcholinesterase inhibitors like donepezil or rivastigmine (risk of cholinergic crisis — do not combine)
Updated Invalid Date