Huperzia Serrata for Memory: Does It Work?

Key Findings

This open-label study evaluated the effects of a supplement containing Huperzia serrata (HS) extract, curcumin, vitamin B12, folate, and other ingredients on cognitive function in patients with Alzheimer’s disease, dementia with Lewy bodies (DLB), or mild cognitive impairment (MCI). The primary outcome was improvement in cognitive scores on the Alzheimer’s Disease Assessment Scale-cognitive subscale Japanese version (ADAS-cog-J). Significant improvements were observed at 6–12 weeks (p = 0.007) and 22–28 weeks (p = 0.004) compared to baseline. However, the combination of multiple ingredients limits conclusions about the specific contribution of HS to these effects.

Study Design

The study was an open-label pilot trial (no placebo or blinding) involving 10 participants (6 with Alzheimer’s, 2 with DLB, and 2 with MCI), aged 70–80 years. Assessments occurred at baseline, 6–12 weeks, and 22–28 weeks. The small sample size and lack of a control group reduce the strength of evidence. Duration was 28 weeks, but the short follow-up periods may not capture long-term efficacy or safety.

Dosage & Administration

Participants received a supplement containing 0.2 mg of Huperzine A (an active compound in HS) and 100 mg of curcumin, administered twice daily. The full composition of the supplement was not detailed, though it also included vitamin B12, folate, and unspecified "others." The HS extract dosage was not quantified separately, making it unclear whether effects stemmed from Huperzine A alone, synergies with other ingredients, or the combination.

Results & Efficacy

• ADAS-cog-J scores improved significantly from baseline (mean 27.7) to 6–12 weeks (mean 21.8, p = 0.007) and further at 22–28 weeks (mean 20.8, p = 0.004).
• Cognitive domains showing improvement included memory, language, and attention, though specific metrics (e.g., effect sizes, confidence intervals) were not reported.
• Adverse events: 2 participants discontinued due to gastrointestinal symptoms (nausea, diarrhea), suggesting potential tolerability concerns.

The lack of a control group and blinding increases the risk of bias, and the small sample size limits generalizability.

Limitations

1. Open-label design: Subjective outcomes like cognitive scores may be inflated by placebo effects or rater bias.
2. Small sample size: Results from 10 participants are insufficient to establish statistical robustness or subgroup differences (e.g., Alzheimer’s vs. MCI).
3. Combination supplement: Effects cannot be attributed solely to HS, as curcumin and other ingredients may independently influence cognition.
4. Short duration: 28 weeks may not reflect long-term efficacy or safety.
5. No confidence intervals: Magnitude of improvement is unclear without effect size or variability data.
   Future research should prioritize randomized controlled trials (RCTs) with larger cohorts, longer follow-up, and monotherapy vs. combination comparisons.

Clinical Relevance

This pilot study suggests a potential cognitive benefit of a supplement containing HS extract and curcumin in dementia/MCI patients. However, the findings are preliminary due to methodological weaknesses. For supplement users, the results highlight the need for caution:
- Huperzine A (0.2 mg twice daily) may contribute to efficacy but could also cause side effects (e.g., gastrointestinal issues).
- The combination with curcumin and other agents complicates interpretation of which ingredient(s) drove outcomes.
- Current evidence is insufficient to recommend HS-based supplements as a standalone therapy without further RCT validation. Patients should consult healthcare providers before use, particularly given the lack of safety data beyond 28 weeks.

The study underscores the importance of isolating HS’s effects in rigorous trials to determine its role in cognitive health.