Polygonum cuspidatum (Japanese knotweed) root extract-sourced resveratrol
Polygonum cuspidatum (Japanese knotweed) root extract-sourced resveratrol is a unrated form of Resveratrol, used in 731 on-market products .
Typical standardization: Varies; labels cite 10-99% resveratrol (e.g. 20%, 50%, 99%)
Why this tier: Botanical-source descriptor (the dominant commercial source -- several hundred on-market rows name it in raw_form) rather than a distinct delivery form; standardization varies widely and no human comparison against synthetic/fermented resveratrol was verified, so it is not ranked. A row whose own name is the plant source (e.g. "Japanese Knotweed Root Extract") declares extract mass, not resveratrol, and is kept unresolved; a "Resveratrol" row that merely lists the plant in raw_form keeps its declared mg.