st contains auxins and other hormones and vitamins. it doesn't say, but allow me to break it down for you; superthrive is a root stim product.

i have done side by side grows, and i absolutely love st. roots are very fat, healthy, white....

no st looked like a normal grow....

wish i had pix, but look at my thread (kp gets her feet wet) and look at my roots.

love, kp