Caffeine Capsules

Caffeine is one of the most studied performance compounds in sports science, and the evidence is unusually consistent: meta-analyses show it reliably improves short-duration power output, endurance, and alertness at 3-6 mg/kg bodyweight. It works by blocking adenosine receptors, which keeps perceived exertion lower for the same workload. Downsides are real too. It disrupts sleep if taken within 6-8 hours of bedtime, and chronic high doses build tolerance. Tested for purity and pharmacopeia-grade potency, not that caffeine is easy to fake.

Also known as: Caffeine anhydrous, 1,3,7-trimethylxanthine