I can almost guarantee that the nystatin is in a glucose base which makes it completely counterproductive as yeast thrives on sugar. I used it when DS and I had a really bad case of thrush and it relieved the pain a little and as soon as the 2 week treatment was over it came back worse than before. I gave in and used gentian violet (I, too, was worried by the cancer study so I avoided it at first) and, because it was SO bad, it took about a week before it was gone. Under normal circumstances it clears it up within 2 or 3 days.
Candida Protocol from Dr. Jack Newman
Using Gentian Violet from Dr. Jack Newman
As I said, I too was cautious because I read about the cancer study. However, I did end up looking it up because I was surprised that it was such a large recommendation in the alternative medicine community if it was supposed to be so bad. Apparently the study was
long term exposure, several times a day. Not once or twice a day for a few days at a time. You'll want the 1% solution, not the 2% solution (as mentioned in the links above) and I read recently that using a 2% solution also may have been a contributing factor to the outcome of the study. Honestly, for short term use, I think the risks of continuing with thrush (most importantly the risk of weaning or baby not nursing enough because of the pain caused by thrush) are much higher than the small risks of gentian violet and you can observe baby for bad reactions. I would be more concerned about the nystatin (because it's SO much and they swallow it and it's used for such a long time) than the gentian violet. Of course, this is after I've already BTDT.
If you are nursing, make sure you
treat both baby's mouth and your breasts. The thrush will NOT be resolved if both of you are not treated.