Supplements
Supplements
This section is small and educational. The supplements covered here are discussed as subjects in their own right — what they are, what has been measured, what the regulators have said — and never as substitutes for prescription medicines.
L-theanine
What the trials measured, and the size of the effect.
Reviewed 12 February 2026
Caffeine supplementation
Tablets, doses and what differs from dietary caffeine.
Reviewed 5 March 2026
“Nootropic” as a term
Where the word came from and why it now means very little.
Reviewed 15 January 2026