Everything DoseRank tracks on the instant coffee shelf — L-Theanine. The category itself is never ranked: 36 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 instant coffee 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 45 health outcomes that matter for this category. Pick yours, and the full evidence-ranked shelf loads for that goal alone.
Calmness or relaxationReduced tension and greater sense of calm.3 rankedStrong
Eye strainVisual fatigue or discomfort from eye use.4 rankedModerate-strong
Macular pigment optical densityRetinal pigment measure sometimes used in lutein/zeaxanthin studies.3 rankedStrong
Contrast sensitivityAbility to distinguish shades or low-contrast details.2 rankedStrong
Visual acuityClarity or sharpness of vision.2 rankedModerate-strong
Bone turnover markersBiochemical indicators of bone formation and resorption.5 rankedStrong
HalitosisBad breath or unpleasant oral odor.6 rankedModerate-strong
Omega-3 indexRed blood cell EPA+DHA content reflecting omega-3 status.4 rankedStrong
IrritabilityLow threshold for frustration or anger.2 rankedLimited
FerritinMarker of iron stores.8 rankedStrong
Anemia statusPresence of clinically meaningful low red cell mass or hemoglobin.13 rankedStrong
HemoglobinBlood oxygen-carrying protein concentration.8 rankedStrong
Potassium statusBody potassium balance.8 rankedStrong
Age-related macular degeneration progressionWorsening retinal degeneration affecting central vision.8 rankedStrong
Vitamin E statusBiochemical sufficiency of tocopherols/tocotrienols.14 rankedStrongNothing is ranked yet — the shelf stays locked until you pick a goal.
No goal, no ranking.
A “best instant coffee supplement” list without a goal would be marketing, not evidence. Pick what you want to improve and DoseRank scores all 36 products against that goal's trials.