Read the label of your deodorant, there are all kinds of crazy additives...spend some time looking at what they mean. Make your decision based on that. And since this is the place where your body releases toxins (more than other places) make your assumptions on that. Because what ever chemical your rubbing on that part of the skin will be absorbed into your tissue and into your blood stream and then essentially throughout your body. But if your question is simply will it stop your from breast feeding time then no. Not eating, or getting enough sleep will cause it. Stress = no good.