Other

Caffeine

Other studied for alertness, exercise performance, reaction time. How it works, the dose and timing studied, what it interacts with, and the research behind the grade.

Grade A evidence strong: trials and meta-analyses agree
All compounds
Best for Alertness, Exercise performance, Reaction time
Typical dose 40–200 mg per serving; up to ~3–6 mg/kg before exercise
Timing Morning to early afternoon; avoid within 8–10 hours of bedtime
Category Other
How it works

What it is and the mechanism

Adenosine receptor antagonist that blocks the buildup of sleep pressure, increasing alertness and reducing perceived effort. It also raises catecholamine signaling, which supports power output and endurance during exercise.

Dose and timing

When and how much to take

The dose below reflects the range used in published research. Match the form alongside the milligrams. Set your own wake and bed times to map the timing onto your day.

Timing visualizer

When to take Caffeine

Dose: 40–200 mg per serving; up to ~3–6 mg/kg before exercise. Set your own wake and bed times to map the guidance onto your day.

12a6a12p6pDAY1 dose
8 amMorning. Take early in the day.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Before you stack it

Interactions and cautions

Read these before combining this with other supplements or medication. The risk is rarely the headline, it is the interaction you did not check.

Interactions
  • L-theanine, smooths jitter at a 2:1 theanine:caffeine ratio
  • Certain stimulants and SSRIs, additive effects
Cautions
  • Disrupts sleep when taken late
  • Anxiety, palpitations, or hypertension, limit intake
  • Pregnancy, keep below 200 mg/day per guidance
Stacking

What pairs well, and what to keep apart

Derived from shared topics, complementary categories, and the interaction list. Introduce one compound at a time so you can tell what works.

Explore more

Compounds in the same topics

Often considered alongside this one. Each carries its own evidence grade.