Caffeine pills

Caffeine is taken as one dose before training, so what matters is how much one serving gives. We compare each product's serving with what studies use: 3–6 mg/kg. Products whose serving reaches that come first, then by how close one serving gets (counted only up to the top of the range); commission never changes the order.

Most caffeine pills are 200 mg. Studies of exercise use 3–6 mg per kg of bodyweight in one dose, and the FDA cites 400 mg a day as an amount not generally linked to negative effects for most healthy adults. Pills labelled with Drug Facts are FDA over-the-counter drugs; ones with Supplement Facts are dietary supplements. Work out your own range.

20 products. The verdict judges one serving, as the label gives it. Read the caffeine guide for the studies behind the dose. "Proof" is a published independent lab test, a certifier listing we read on the certifier's own site (usually for listed lots only), or "Label claim only" when we found neither.