Most “nootropic” results vanish when sleep, stress, and workload aren’t stable. Start with foundations, then experiment with compounds only if the signal is strong and the risk is low.
If you experiment, start with one low-risk change and a clear stop rule. Use the Interactions Database as a starting point.
ABAB a single variable (e.g., caffeine cutoff or morning light timing) and measure focus during the same 30–60 minute work block each day.