There are different type of testosterone supplements out there. Some of these supplements contain tropinol. How does tropinol work? you might ask yourself. I have wondered the same thing, but before taking a supplement, I would read about the side effects especially the natadrol side effects. Men contain about 7 or 8 times more testosterone than women which is why men might consider taking this important supplement. Testosterone can help your prostate, and it can also help osteoporosis.