Huperzine A

Also known as: Hup A, selagine

Grade B — Moderate Evidencenootropiccognitive
50–200 mcgMorning or early afternoon. Cycle: 5 days on / 2 days off. Do NOT take continuously.

Huperzine A is an alkaloid derived from the Chinese club moss Huperzia serrata that acts as a potent, reversible acetylcholinesterase inhibitor, effectively increasing acetylcholine levels in the brain. Clinical trials in China have shown improvements in memory and cognitive function in both Alzheimer's patients and healthy adolescents. It has a long half-life (~10 hours) and should be cycled to prevent receptor downregulation.

TL;DR: Potent acetylcholinesterase inhibitor. Effective for memory but narrow therapeutic window — cycling and careful dosing required.

🧠Cognitive Performance🎯Focus
Last reviewed: 2026-03-12

Quick Facts

Evidence

Grade B

Studies

3

Interactions

3

Forms

1

Evidence Rating: Grade B — Moderate Evidence

Some RCTs with positive results, or strong observational evidence. More research may refine our understanding.

Cycling Protocol

4 weeks on/2 weeks off

Long half-life and potent acetylcholinesterase inhibition — cycling prevents excess acetylcholine buildup

Interaction Warnings

Cholinesterase inhibitors (donepezil, galantamine, rivastigmine)High Risk

CONTRAINDICATED — dangerous additive cholinergic toxicity

AnticholinergicsModerate

Antagonism; reduces both effects

Beta-blockersModerate

Potential bradycardia via cholinergic stimulation

Important Notes

  • Very low doses (MICROGRAMS) — dosing errors are dangerous
  • MUST cycle use to avoid receptor downregulation
  • Not for cardiac arrhythmias, peptic ulcer, bradycardia, epilepsy

Clinical Evidence (3 studies)

Huperzine A improved memory in Alzheimer's

Xu SS et al. (1999) — Zhongguo Yao Li Xue Bao

Improved memory in Alzheimer's patients; RCT

View on PubMed

Cochrane-style review: Huperzine A for Alzheimer's

Yang G et al. (2013) — PLoS ONE

Modest beneficial effects across multiple trials

View on PubMed

Huperzine A improved memory in school students

Sun QQ et al. (1999) — Acta Pharmacol Sin

Improved memory in healthy school students

View on PubMed

Alternatives to Consider

These supplements target similar goals and may be worth considering alongside or instead of Huperzine A.

Magnesium L-Threonate

Grade B

The only magnesium form shown to cross the blood-brain barrier effectively. Promising for cognitive function and brain aging.

🧠 Cognitive Performance🎯 Focus

L-Theanine

Grade B

Amino acid from green tea. Promotes calm focus (alpha brain waves) without drowsiness. Excellent safety profile.

🎯 Focus🧠 Cognitive Performance

Lion's Mane

Grade B

Medicinal mushroom that stimulates NGF. Multiple RCTs show benefits for mild cognitive impairment and mood.

🧠 Cognitive Performance🎯 Focus

Related Supplements

Magnesium L-Threonate

Grade B — Moderate Evidence

The only magnesium form shown to cross the blood-brain barrier effectively. Promising for cognitive function and brain aging.

L-Theanine

Grade B — Moderate Evidence

Amino acid from green tea. Promotes calm focus (alpha brain waves) without drowsiness. Excellent safety profile.

Lion's Mane

Grade B — Moderate Evidence

Medicinal mushroom that stimulates NGF. Multiple RCTs show benefits for mild cognitive impairment and mood.

Alpha-GPC

Grade B — Moderate Evidence

Most bioavailable choline source for the brain. Supports acetylcholine production for memory, focus, and muscle contraction.

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⚕️ Important Disclaimer

This information is for educational purposes only. It is not medical advice. Always consult a healthcare provider before starting any supplement regimen, especially if you take medications or have health conditions.

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