I've used it and all I can say is when I used it on 2 plants I harvested the same amount as I did with 4 plants without using it off the same strain and everything my first grow was with miracle gro soil and ferts. and my second was with foxfarm products so if that tells you anything this time it's foxfarm soil and ferts. with superthrive the whole way and my girls are huge I cut back to every other watering at flowering stage but I say yes to superthriveSome people swear it works, others swear it's BS.
I have seen it cause problems in flowering so I would say that whether it helps or not, don't use it anywhere near the flowering cycle.
I don't use the stuff personally, I'm pretty skeptical that it does even a minor degree of what they claim it does.
man if you follow what it says your plants will thrive but I'm on another thread and they say it's not good to use it at flowering or it will shorten your yield I know I didn't use it as much during flowering and I had fat nugsI've heard good reviews and people who stand by it so I'm giving it a try. Its basically a vitamin B and hormone concentrate which can't be bad but it is VERY concentrated. You literally use drops per gallon. I accidentally put too many drops and noticed some burn today, but I will continue to try as the user endorsement on DH was very positive about it. my 2