Just thought of checking my Herb books. Lycopus Virginicus is different from the Chinese species “Lycopi lucidus” for your info.
To add to what Jeannette said, I quote from “planetary herbology”-
“–has been shown to be effective for sedating high thyroid, especially when combined with motherwort. Effects are only noted after taking the combinations for two weeks.”
This book says it should only be used in its fresh state, or freshly tinctured, not dried.
Bruce