I use D-mannose as soon as I feel like a uti might come on, mainly after my partner and I have been intimate.
I suffered terribly with uti like symptoms, it got unbearable when I had to switch from patches to gel, I didn't absorb it. Once back on the patches it improved in a few days with the help of D-Mannose. I got mine from Amazon, flat white container with blue writing on, I'll have to look up the make, it has good reviews. x