Bristol Botanicals have Sophora root tincture, dried herb and powder (Sophora is the herb you get Oxymatrine from). The White Tiger brand typically recommended was only available from biomed Netherlands when I checked last year. I ordered it from there online without issues, it required a few e-mails, but came delivered as expected. The purest form of Oxymatrine available seems to be the Alternative Medicine Solutions brand which I bought from Amazon. This is the only form of Oxymatrine I tested that doesn't produce uncomfortable dizziness 2 hours after ingestion.