Focus

What attention supplements can move

Attention rides on arousal chemistry: adenosine pressure dragging alertness down, catecholamines pushing it up, and the narrow band between alert and jittery where good work happens. Most focus supplements move one of those dials — caffeine blocks adenosine, and theanine adds a calm-alert signature measurable on EEG.

The ceiling is lower than the marketing implies. The firmest evidence is for caffeine, and for the caffeine–theanine pairing improving attention accuracy beyond either alone. Creatine and rhodiola show narrower, situational signals — sleep loss, exam stress. Sleep itself remains the active ingredient no capsule replaces; the list below is graded accordingly.

Caffeine at 40–300 mg supports vigilance, reaction time, and attention, with larger effects during sleep restriction. Paired with L-theanine — 150 mg caffeine with 250 mg theanine in one crossover, 40 mg with 97 mg in another — the combination improved attention-task accuracy and task-switching beyond either compound alone.

Creatine’s cognitive signal is narrower than its strength record. A six-trial review found support for short-term memory and reasoning mainly under metabolic stress — sleep loss, low dietary creatine — and inconsistent elsewhere. Rhodiola in one 40-person exam-period trial improved self-rated wellbeing; the cognitive-test results were mixed.

What this page is

This hub is a ranked reading of the focus pairings we store. It is not a store, not a coach, and not a productivity protocol. We will not write caffeine as a substitute for sleep, and we will not write creatine as an everyday attention capsule.

Medications and current intake change the list — caffeine with blood-pressure medication, rhodiola with SSRIs or stimulants. Check the interactions page, then build. Education, not medical advice — talk to your doctor or pharmacist before changing anything.

How grades work on this hub

Caffeine is the A pairing: a large human record for alertness and attention. L-theanine is B for the caffeine pairing, not as a stand-alone attention tool. Creatine and rhodiola are C — situational, smaller, or mixed.

The letter is for the pairing we store. Creatine can be A for strength and C for focus on the same site. Grade D never appears on this list. The scale lives on the grade explainer; the records are in the evidence index.

How to read a grade · Evidence records

Ranked by evidence

How to read a grade

1. AA — multiple human RCTs Caffeine 50–200 mg as needed; pairing with l-theanine smooths the edge

   McLellan TM, 2016

2. BB — one solid RCT or consistent meta-analytic signal L-theanine 100–200 mg with caffeine for attention work; fine alone for calm alertness

   Giesbrecht T, 2010 · Haskell CF, 2008

3. CC — human observational or small pilots Creatine monohydrate 3–5 g daily; cognitive support shows mainly under sleep loss or low dietary creatine

   Avgerinos KI, 2018

4. C Rhodiola rosea 200–400 mg in the morning during demanding stretches; not an everyday stimulant

   Spasov AA, 2000

Grades are per goal–ingredient pairing, hand-assigned from the evidence records linked below each name. Browse all records. Ingredients without a monograph link have a page on the way.