SANGUISORBA OFFICINALIS ROOT EXTRACT HAS FGF5 INHIBITORY ACTIVITY AND REDUCES HAIR LOSS BY CAUSING PROLONGATION OF THE ANAGEN PERIOD - one of the scientific articles. Thus, it does nothing to prevent your follicles from DHT.
The thing with this product is that it's only had one clinical trial. I was looking through the forum and Hellouser already reviewed the study and figured it was probably bogus.
They're making a lot of money though, that's for sure.