In the hydroponics world it is VERY highly regarded. As a "tonic" and a rooting enhancer. Generally a B-1 (Thiamine hydrochloride if I remember correct) blend it seems to be very effective. I did a little experiment a number of years back with some rooting powders and other snake oils and Superthrive had almost double the roots and fast compared to NAA, IBA (3 different strengths, 2 different brands) and a cytokinin product.