Comparison guide

Which caffeine should you take?

All three deliver the same stimulant, and in each of them the caffeine does most of the work. What differs is how fast it kicks in and whether something takes the edge off, not how large the benefit is.

The options, compared

Option	Evidence	Best for	The honest note
Caffeine	Strong evidence	Most people	The reference form, with strong evidence for performance, alertness and focus; studied at 3–6 mg/kg taken 30–60 minutes before exercise.	View
Caffeine Gum	Moderate evidence	Dosing close to start time	Absorbed through the cheek, so it reaches the blood faster and can be taken roughly 5–10 minutes before exercise instead of 60. The performance effect is the familiar caffeine effect, not a bigger one, and gains in strength and jumping are less consistent.	View
Caffeine + L-Theanine	Moderate evidence	If caffeine alone makes you jittery	Theanine takes some of the edge off, and a meta-analysis found the pair improved simple attention more reliably than either alone. Effect sizes were small, and most of the benefit comes from the caffeine.	View

Our verdict

Plain caffeine is the default: it is the cheapest and best studied, and the other forms deliver the same caffeine effect. Use gum only if you need faster onset, and add L-theanine if caffeine on its own leaves you jittery. Whatever the form, keep total intake under about 400 mg/day (200 mg/day in pregnancy) and avoid it late in the day.