The world's favorite stimulant.
The FDA says 400mg a day is fine for most adults. That's about four cups of coffee. Some people are more sensitive.
Myth. It's a mild diuretic, but the liquid it's in usually offsets the effect. Just drink water like a normal person.
Yes, if you take it too late. Its half-life is about 5-6 hours. Stop all caffeine by 2 PM if you want to sleep well.
Click through to the studies bar for the evidence base.
See the dosing guide below.
Compare formats before buying.
Some ingredients build up over weeks. Others act fast.
The compound effect of consistent dosing.
Check the cautions section if you have a pre-existing condition.
Some ingredients you feel. Others just work in the background.
You can become dependent. Skipping it might give you a headache and make you cranky for a day or two. It's not a true addiction.
Pills give you a precise dose. Coffee has other beneficial compounds. Both work. Pick what's convenient for you.
It slightly boosts metabolism, but not enough to make a real difference on its own. Don't count on it for fat loss.
Good idea. Taking a week off every 1-2 months can help reset your tolerance to the 'alertness' feeling.
Most research uses 0.2g daily. Below 0.1g, you're probably wasting money. Above 0.4g, no extra benefit. The curve plateaus. Safe upper limit ~ 0.4g.
The most studied psychoactive compound.
Coffee beans · Tea leaves · Cacao pods · Kola nuts · Guarana berries
Caffeine interacts with other supplements and meds. The analyzer flags interactions, dose mismatches, and timing collisions across your whole list.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.