We bought this stuff on the recommendation of the doggy oncologist we saw after learning of our 11 year old dog's hemangiosarcoma. He had recently had his spleen out and tumors were bound to start growing inside him again at some point. Sadly, he was only on these (plus a cancer pill) for about a month before he passed away. Perhaps these capsules prolonged his life, but it's impossible to know. Now we have a huge stock of these pills! Maybe I'll try to sell them online...