Short answer
Most women start noticing changes around day 10. By day 21, the shift is usually unmistakable.
The typical timeline
Day 1–7: subtle — a mild hydration shift, sometimes less afternoon fog.
Day 10–14: the afternoon slump starts to quiet down. This is usually the first thing women notice.
Day 21: improved focus and "mental clarity" become clear. Clothes may start fitting differently.
Day 45–60: a second, deeper wave — body composition shifts become visible to others, mental clarity stops feeling new and starts feeling normal.
8–12 weeks: optimal body-composition results for those who stay consistent.
Notes
The shift is quiet, not dramatic — this isn't a stimulant.
Individual responses vary; some women feel it sooner, a few need closer to a month. Both are normal.
Consistency is the single biggest factor — missing days slows the process.