Everything DoseRank tracks on the l-phenylalanine shelf — Huperzine A. The category itself is never ranked: 21 products get scored the moment you say what you want them to do.
How to read the scores
This legend covers the scores on this page — for data sources, scoring weights, and limits, read the full methodology →
Answer a few questions about your goals, habits, stack, and budget. Then, DoseRank will find the products that best match your needs based on your answers. It's free and only takes 60 seconds! No account is required.
A saved, shareable breakdown: your matched products, dose math, interaction flags to discuss with a clinician, and a price-tracked stack you can revisit.
Questions
Each product gets a composite score blending clinical strength, evidence, dose fit, trust and value — computed for the goal you picked, across this category's products. The #1 on the DoseRank tab has the highest composite; the other tabs re-rank the same products by Value, Trust, or Popularity. Placement is never paid.
Start with a goal, not a brand
Browsing l-phenylalanine supplements without a goal makes no sense — different products do different jobs, and “best” flips depending on which job you're hiring for. These are the 11 health outcomes that matter for this category. Pick yours, and the full evidence-ranked shelf loads for that goal alone.
Activities of daily livingCapacity to complete routine self-care activities independently.1 rankedStrong
Attention and concentrationAbility to sustain and direct focus.5 rankedModerate-strong
Calmness or relaxationReduced tension and greater sense of calm.1 rankedStrong
Niacin statusBiochemical sufficiency of vitamin B3.1 rankedStrong
Iodine statusBiochemical sufficiency of iodine.1 rankedStrong
MemoryAbility to encode, store, and retrieve information.1 rankedStrong
Vitamin C statusBiochemical sufficiency of ascorbic acid.1 rankedStrong
Sleep qualityOverall restfulness and perceived quality of sleep.2 rankedModerate-strong
Thyroid functionOverall function of the thyroid axis.1 rankedStrong
Anxiety symptomsWorry, tension, fear, or related anxiety manifestations.1 rankedStrong
Cognitive functionOverall thinking ability including memory, attention, and processing.1 rankedStrongNothing is ranked yet — the shelf stays locked until you pick a goal.
No goal, no ranking.
A “best l-phenylalanine supplement” list without a goal would be marketing, not evidence. Pick what you want to improve and DoseRank scores all 21 products against that goal's trials.