This site labels this specific theme with a single initial, C, rather than a full name — worth reading what this theme actually describes.
This site describes it directly: the most common comment is feeling less foggy through the afternoon after several weeks of daily use — worth reading "several weeks" as a specific, checkable timeframe within this theme.
This site is direct elsewhere that it does not publish star ratings or named testimonials it cannot verify — worth reading this initial-only labeling as consistent with that stated caution around unverifiable claims.