Caffeine
Also known as: 1,3,7-Trimethylxanthine, Coffee extract, PURENERGY, caffeine co-crystal, caffeine pterostilbene
Overview
Most widely used performance enhancer. Improves endurance, strength, and cognitive function through adenosine antagonism.
Frequently Asked About Caffeine
How much Caffeine should I take?
When is the best time to take Caffeine?
Should I take Caffeine with food?
Does Caffeine interact with medications?
What does Caffeine pair well with?
Who should not take Caffeine?
What are the side effects of Caffeine?
Dosage
Tolerance develops; cycle
Athletes, shift workers
Research & Studies
We haven’t curated landmark studies for Caffeineyet — one-click into the primary literature here. PubMed (RCTs) is usually the highest-signal starting point.
Mechanism of Action
- • Blocks adenosine receptors
- • Increases catecholamines
- • Enhances fat oxidation
- • Central nervous system stimulant
Evidence Quality
Proven ergogenic aid
Safety & Contraindications
- • Overdose possible with powder
- • Arrhythmias
- • Severe anxiety
- • Anxiety
- • Insomnia
- • Jitters
- • Dependency
Limit to 200mg/day in pregnancy
Safe
Interactions
- • Many interactions
- • Enhances stimulants
- • Synergistic with L-theanine
- • Alcohol may mask effects
Stacking & Synergies
Buying Guide
- • Precise dosing form
- • Cycle to maintain sensitivity
- • Cut off 6-8h before bed
- • Tolerance develops - cycle off periodically
- • Combine with L-theanine for smoothness
Top Products with Caffeine
Highest-scored catalog products containing Caffeine, ranked by our scoring engine.
Browse all Caffeine products →Related Guides
In-depth guides covering Caffeine — protocols, comparisons, and use cases.
More in Performance
Other ingredients in the Performance category.
Cite this page
Formulate Research Team. (2026, June). Caffeine — Evidence-Based Supplement Guide. Formulate Supplement Encyclopedia. https://app.formulate-health.app/learning/supplements/caffeine
Educational content based on published research and our scoring methodology. Not medical advice — consult a qualified healthcare provider before starting, stopping, or changing supplements, especially if you take medications, are pregnant, or have a medical condition.