It's a pineapple enzyme that's good for digestion. It's also touted as an anti-inflammatory. I have taken it after heavy meals, and it seems to work in the digestion area, but don't know about its other properties.
I've also used it to improve digestion, it seems to work well.
Bromelain is a natural blood thinner because it prevents excessive blood platelet stickiness. Be very careful when taking this.
gemfire, that's good to know. I already take fish oil, which probably thins the blood enough.