Caffeine

Food compounds and supplements used around strength, power, endurance, hydration, and recovery. Sport context should stay separate from disease treatment claims.

Page last reviewed: 2026-07-23 - next review due: 2027-01-23

High-Caution Safety Flags

Use extra caution before concentrated supplement use, especially with medications, pregnancy, liver/kidney disease, heart conditions, or complex medical history.

pregnancy/breastfeeding, sleep, anxiety, heart rhythm, blood pressure

Source Coverage

Included: US reference

Review gap: Canadian reference

Add or verify Health Canada context where an official Canadian reference exists.

Review gap: EU reference

Add or verify EFSA or EU health-claim context where an official EU reference exists.

Included: Clinical / safety source

Function

Central nervous system stimulant that can support alertness and exercise performance in some contexts.

Natural Sources

Coffee, tea, yerba mate, guarana, cacao.

Food vs Supplement Context

Natural sources describe where this item appears in foods, culinary ingredients, or traditional preparations. Concentrated supplements can differ by dose, extract type, preparation, standardization, and medication context, so they should be evaluated separately.

Testing & Monitoring Context

No routine lab test establishes a required daily need for most foods and bioactives; monitoring is usually based on the intended outcome, dose, medical history, and adverse effects.
Blood-pressure context: monitor blood pressure and medication effects when concentrated products are used.
Sedation context: watch for next-day drowsiness, impaired driving, alcohol overlap, or sedating medication combinations.
Caffeine context: sleep quality, anxiety, heart rhythm symptoms, blood pressure, pregnancy status, and total daily caffeine from all sources matter.

Suggested Guidelines When Purchasing

What to look for: Prefer a product identity that matches the studied ingredient or ordinary food source described on this page.

Use caution or avoid: Avoid casual use when these flags apply: pregnancy/breastfeeding, sleep, anxiety, heart rhythm, blood pressure.

Prefer ordinary food sources first when they provide the intended compound in a practical way.
For supplements, require clear labeling of active ingredient, dose per serving, serving size, and other ingredients.
Prefer products with third-party testing or transparent contaminant testing, especially for concentrated extracts, algae, mushrooms, minerals, and sports products.
Do not let marketing claims override the evidence, safety flags, source coverage, or dose context on this page.

Intake Guidance

Limit or safety context

FDA cites 400 mg/day as an amount not generally associated with negative effects for most adults.

This is a safety context, not an RDI or a target to reach.

Pregnancy, breastfeeding, anxiety, sleep problems, heart rhythm issues, medications, and individual sensitivity can require lower intake.

Evidence Summary

Exercise performance and alertness

Established use

Caffeine has consistent human evidence for improving alertness and several exercise-performance outcomes, with response varying by dose, timing, tolerance, and genetics.

Dose context: Sports literature often studies about 3-6 mg/kg before exercise; FDA safety context for most adults is up to 400 mg/day.

Caution: Sleep disruption, anxiety, pregnancy, cardiovascular concerns, and medication interactions can lower an appropriate intake.

Studies/sources: ISSN Position Stand: Caffeine and Exercise Performance (2026-07-23), Spilling the Beans: How Much Caffeine is Too Much? (2026-07-23)

Evidence Legend

Established use: Supported by official guidance, regulatory claim context, strong consensus, or repeated human evidence for a specific use.

Promising: Human studies or reviews suggest benefit for specific outcomes, but evidence is not broad enough to treat as settled general guidance.

Emerging: Early human, mechanistic, or mixed evidence; worth tracking, but not strong enough for confident user-facing claims.

Traditional use: Historically or traditionally used, but modern clinical evidence may be limited, mixed, or product-specific.

Category example: Included to describe a supplement or food category, not because a strong health claim is attached yet.

Research Links

Use this as a research discovery link. Search results are live and may change, so curated sources on this page remain the fixed references for app content.