My dogs have been on fish oil for a long time. While their coats are nice and shiny, I did not see any new hair growth from it. For Dessie and Disco, it is the Melatonin that is making they fuzzy. I did not see any decrease in their level of activity either. Of course with Disco, it's pretty hard to tell extremely laze from incredibly lazy. :lol
But I love the new soft and fuzzy fur they are growing. So even if I am messing with their hormones just to grow coat, they will continue it. I personally don't think there is enough of the actual hormone in most OCT products to really call it a hormone anymore. But than again, what do I know anyway. We have only had 7 greyhounds, far from the level that would make us experts or hero'es.