Is a higher dose always better?

No. Dose-fit rewards landing inside the range studied for the outcome — over-dosing (common with melatonin) or under-dosing both lower the score. The goal is the effective dose, not the biggest number.

What does the Value score mean?

The Value score compares a product's price per serving with clinically relevant products ranked for the same outcome. A score of 50 is the typical price; above 50 means better value than typical, while below 50 means the product costs more than typical. It is a 0–100 value signal, not a percentile.

Why is the cheapest product not #1?

Cost is only one input. The cheapest pick here is a citrate form with weaker absorption and a stock-risk flag, so it leads on Value-for-cost but trails on the composite that also weighs evidence, dose fit and availability.

Are these affiliate links?

Retailer links may be affiliate links and DoseRank may earn a commission. Rankings and placement are determined by the scoring model only — never by payment from a brand.

Is this medical advice?

No. DoseRank summarizes evidence to help you choose; it is not a substitute for a clinician, especially if you are pregnant, breastfeeding, on medication, or managing a health condition.

Improve focus and concentration

What this outcome means

Attention and concentration are your ability to lock onto a task and hold focus without drifting, even when distractions pull at you. On DoseRank it maps to a defined health outcome built from human studies on sustained-attention task performance, reaction time, and error rates – data sourced from open sources and specialized resources. DoseRank is not medical advice.

Who it's for

Easily distractedFocus that scatters the moment a notification or noise appears.

Long-task fadeConcentration that slips during extended reading, study, or detailed work.

Mentally scatteredJumping between tasks and struggling to settle on one.

Stack buildersAlready taking supplements such as L-Tyrosine or Huperzine A and want the dose right.

Evidence level

70Moderate-strong

L-Tyrosine and L-Theanine – have moderate public evidence for this outcome. This usually means there are smaller or mechanistic studies, but not randomized human trials. A DoseFit Score of 77 means this product's ingredient forms and doses are close to what was used in the studies behind this ranking - DoseRank weights each product ingredient.

Best available ingredients

L-Tyrosine and L-Theanine lead this outcome, supported by Huperzine A and L-Phenylalanine.

Dose matchedDoseFit 77

Scores reward products dosed inside or above the studied range, not just the right ingredient. Examples: In range: Huperzine A 80 mcg vs 50-200 mcg, L-Theanine 200 mg vs 100-250 mg; Below range: L-Tyrosine 100 mg vs 2000-10000 mg, L-Phenylalanine 200 mg vs 500-1500 mg.

Thin spots

Huperzine A and L-Phenylalanine have low evidence for this outcome, so they are flagged as evidence gaps rather than treated as proven drivers.

Processed

1.8k

Available

1.8k

Ingredients

Brands

274

Coverage

100%

How to read the scores

What every metric means

Each score is 0–100. Higher is better for every metric below.

CompositeThe overall DoseRank score — a weighted blend of clinical strength, evidence, dose fit, trust and value.Higher is better

ClinicalHow strongly the formula's ingredients and doses match what clinical studies used for this outcome.Higher is better

EvidenceHow much published human research backs the formula's key ingredients for this outcome — both how many studies exist and how strong they are.Higher is better

ValueHow the price per serving compares with similar products for this outcome — 50 is the typical price, higher means better value for your money.Higher is better

TrustHow well customers rate this product, with extra weight given to ratings backed by a large number of reviews.Higher is better

PopularityHow strongly this product sells compared with the other ranked products for this outcome.Higher is better

This legend covers the scores on this page — for data sources, scoring weights, and limits, read the full methodology →

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Get a personal report

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

Frequently asked

Each product gets a composite score blending clinical strength, evidence, dose fit, trust and value. 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.

Improve focus and concentration

What this outcome means

Who it's for

Easily distractedFocus that scatters the moment a notification or noise appears.

Long-task fadeConcentration that slips during extended reading, study, or detailed work.

Mentally scatteredJumping between tasks and struggling to settle on one.

Stack buildersAlready taking supplements such as L-Tyrosine or Huperzine A and want the dose right.

Evidence level

70Moderate-strong

Best available ingredients

L-Tyrosine and L-Theanine lead this outcome, supported by Huperzine A and L-Phenylalanine.

Dose matchedDoseFit 77

Thin spots

Huperzine A and L-Phenylalanine have low evidence for this outcome, so they are flagged as evidence gaps rather than treated as proven drivers.

Processed

1.8k

Available

1.8k

Ingredients

Brands

274

Coverage

100%

Relevant ingredients

Which ingredient types matter for attention and concentrationOpen to see which ingredient types matter for attention and concentration

1.5k products across 5 ingredient types — open to filter the ranking.

Use types to filter ranked products

Botanicals/Herbal Extracts

83 products

Concentrated plant and herbal extracts standardized to actives. Potency depends on the extract ratio and marker content, not raw weight.

Typical:

Antioxidants & Bioactive Compounds

67 products

Molecules that neutralize free radicals and tune cell signaling. Helpful in balance; mega-doses can blunt the body's own adaptive defenses.

Typical: ,

Amino Acids & Derivatives

1.2k products

The building blocks of protein, taken singly for targeted effects – leucine for muscle, theanine for calm. Free-form versions absorb fast on an empty stomach.

Typical:

Alkaloids & Stimulants

65 products

Plant-derived nitrogen compounds like caffeine that stimulate the nervous system. Effective but dose-sensitive, with real tolerance and dependence risk.

Typical:

Fatty Acids & Lipids

131 products

Dietary fats including omega-3s and structural lipids. Look at the active EPA/DHA amounts and freshness, since oils oxidize and turn rancid.

Typical:

Top decision cards

Best products for attention and concentration

Ranking by · Composite outcome score

Best overall — the composite outcome score.

Top pick · DoseRank

Why this ranks #1 for attention and concentration

California Gold Nutrition, SimplyOne®, Think Clearly with L-Theanine, L-Phenylalanine, and L-Glutamine, 30 Tablets

California Gold Nutrition$0.22 / serving4.6 · 2,188Available now

Also helps with

Calmness or relaxation

Niacin status

Vitamin C status

Why this ranks here

Evidence fitL-Tyrosine and L-Theanine have moderate human evidence for this outcome.
Dose fit2 of 4 dosed ingredients land in the studied range. L-Tyrosine at 100 mg sits below the studied 2000-10000 mg window.
Price / serving$0.22 per serving — mid price tier for this outcome.
AvailabilityIn stock across major retailers; 99% availability confidence.
TrustSolid trust signals from buyer ratings, with room to grow.

The numbers

100 mgBelow rangebelow the studied 2000-10000 mg window

80 mcgIn rangeinside the studied 50-200 mcg window

200 mgIn rangeinside the studied 100-250 mg window

200 mgBelow rangebelow the studied 500-1500 mg window

100 mg

100 mcg

200 mg

25 mcg

35 mg

20 mg

Compare top 3 Product data Open at retailer

The rest of the ranking · DoseRank

Top 10 ranked products

Codeage, E-Sport Vitamins+, 90 Vegetable Capsules

CodeageClinical95Dose fit76Popularity30$2.00/ serving

Mt. Capra, Focus, 90 Capsules

Mt. CapraClinical95Dose fit78Popularity30$2.33/ serving

Zahler, TeenFocus™, 90 Capsules

ZahlerClinical92Dose fit73Popularity30$1.08/ serving

Nutricost, CDP Choline, Citicoline, 120 Capsules

NutricostClinical82Dose fit71Popularity91$0.21/ serving

Life Extension, Citicoline (CDP-Choline), 60 Vegetarian Capsules (250 mg per Capsule)

Life ExtensionClinical84Dose fit90Popularity98$0.77/ serving

Sports Research, Organic Collagen Peptides, Matcha, 10.2 oz (288 g)

Sports ResearchClinical87Dose fit74Popularity76$1.20/ serving

Jarrow Formulas, Citicoline, CDP Choline, 250 mg, 120 Capsules

Jarrow FormulasClinical82Dose fit67Popularity91$0.40/ serving

Nutricost, Performance, Creatine + Energy, Grape, 9 oz (252 g)

NutricostClinical87Dose fit90Popularity30$0.60/ serving

Nutricost, Performance, Creatine + Energy, Peach Mango, 9.4 oz (264 g)