there's absolutely not side effects from d-mannose. I've taken both the powder form (hey, it's just like sugar, so you can even take it in your tea/coffee. I take mine straight up and chase it with water), and pill form (perfect for traveling).

I've not gotten a UTI while taking d-mannose as a preventative measure, but I HAVE gotten it when I stupidly forgot to take it with me on holiday. I suffered for 5 days in England while I waited for it to be delivered via snail mail, and at that point I was taking a teaspoon every hour. By the second hour I was experiencing some relief, and by the third I was feeling so much better.

For prevention I take either 1 teaspoon, or 1 pill before if I remember it, or after getting me some lovin'