Decision map
The answers this section helps you reach.
Start with the question that can change your decision. Each summary below gives the current bottom line and opens a complete guide with evidence, limits, and practical next steps.
Important limitationsUse & safety
Follow the package you actually receive. Merchant pre-activity guidance and the official OTC label serve different purposes and should both be checked.
Work through this decision →Practical guideFor sprinters
Repeated-power athletes are the most defensible audience for a measured trial, but the pilot does not guarantee an effect for an individual sprinter or team-sport athlete.
Work through this decision →Practical guideFor endurance
The current direct evidence is too sprint-specific to support a confident endurance-performance recommendation; an endurance buyer should demand a narrower reason to try it.
Work through this decision →Practical guideTroubleshooting
Do not respond to an unclear result by applying more or changing several variables. Return to the current label, standardize the test, and stop for irritation or concerning symptoms.
Work through this decision → 4 practical guides
Choose the question closest to yours.
These pages are deliberately separated when they answer different buyer questions. Related links reconnect the parts without forcing you through a fixed reading order.