Caffeine
Also known as: 1,3,7-trimethylxanthine, caffeine anhydrous, natural caffeine, coffee extract
Effective Dosage
200 mg per dose based on study doses
What the Science Says
Caffeine is a naturally occurring stimulant found in coffee, tea, and many supplements. The provided studies show it increases muscle strength, enhances rowing performance, and modulates brain excitability — specifically improving sensory-motor integration in the cortex. At 200 mg doses, it delivers measurable physical and cognitive benefits, though it can raise blood pressure, heart rate, and LDL cholesterol with regular use, and impairs sleep quality when consumed in the evening.
What It Doesn't Do
Won't significantly boost muscular endurance on its own — the provided data shows strength gains but not endurance improvements. Not a clean substitute for sleep. Doesn't improve metacognitive accuracy — caffeine craving states are actually linked to poorer mental monitoring. Not risk-free: regular use raises cardiovascular markers including blood pressure and LDL.
Evidence-Based Benefits
Well-proven stimulant. Improves alertness, focus, physical performance.
Strong EvidenceEffective at: 100-400mg daily (varies by tolerance)
Source: FDA, NIH
Absorption & Bioavailability
Good — caffeine is rapidly absorbed orally; studies used chewing gum and standard oral doses with clear physiological effects observed within the study windows.
Red Flags to Watch For
- Raises systolic blood pressure (+3 mmHg) and heart rate (+11.9 bpm) with regular daily use — a concern for people with cardiovascular risk
- Evening use significantly impairs sleep quality — athletes training at night should consider alternatives like paraxanthine
- Raises LDL cholesterol with regular consumption, particularly from unfiltered coffee sources
- Caffeine craving and withdrawal states are associated with impaired cognitive monitoring and calibration
- Over 1,000 registered supplement products contain caffeine — doses vary widely and stacking products can lead to unintentional overdose
Products Containing Caffeine
See how Caffeine is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06