Hate to bring up a zombie thread, but I feel the info may be useful for whoever is looking to use Bud Blood.
I discussed bloom stimulation products like MoaB, Shooting Powder, and Bud Blood with my hydro guys. According to them, the primary function is not to merely boost PK.
The products have hormones that induce/force flowering. The result of using it is meant to induce flowering earlier and reduce node spacing. These hormones aren't listed due to obvious reasons given by any company that tries to stay competitive in its marketplace.
What I've noticed is that the harvests where I skipped Bud Blood ($$$ saving decision) were not as good as the harvests when I used Bud Blood as described on the packaging. When I say "good" I am talking only about YIELD, not QUALITY OF SMOKE. There's no way I can tell you the actual return on investment with this product because I didn't track the difference and there were other factors that may have contributed to smaller yield.
I'm not going to argue with anyone over the usefulness or provide pictures. Take my feedback at face value and do with with it what you want: I think Bud Blood is a helpful product, too bad it's so damn expensive. You can pick it up in small packets (40g) these days for around $12 from your local hydro store and give it a try if you're curious. Testing it isn't going to cost you much and you'll have peace of mind having tried it on your own with your setup and your strain.