Typical doctors. Treat the symptom with bcp's and ignore the cause. Estrogen and progesterone cause fibroids to grow. Post menopausal women do not get fibroids. But doc's will rx bcp's because it normalizes a woman's periods. And the fibroid is having great fun growing like crazy off of these increased hormones!

There is a drug that puts you into temporary menopause that makes fibroids shrink, but unfortunately you also get hot flashes.

I have fibroids and have never had spotting whilst riding - but I'm a roadie and you're an mtb'er.

I would look at soy because it normalizes estrogen levels - but don't go overboard because soy interferes with zinc absorption. Avoid dong quai because that makes bleeding worse. Black cohosh is also a possibility that might help normalize your estrogen levels.

None of the above are overnight fixes. They can take up to three months to work.