@Lillianne It really is a suck it and see. Doesn't work at all for some, kind of works for some, and does really well for some. The important thing is to make sure it fits snugly so try to get a nurse who understands it to do the initial fitting. Then they'll often put a cap that's a size smaller on top to help. Then make sure that the sizing of both caps is recorded - best you keep a record yourself. You'll have to ensure during the treatment that it has good contact with the scalp everywhere. I reckon it's worth a go. I chose to stop when I felt that it wasn't working well enough for me after two treatments but if my bald spot hadn't been so hard to hide, I probably would have continued. And if it doesn't work, it's not the end of the world.