If your supply is low whether you're breast feeding or exclusively pumping, I suggest Mother's Milk tea. It's in the tea section (not the baby section) and in a little pink box. It's only $5 with tax give or take some cents, and has 15 tea bags per box. Has a hint of black licorice but NOT so overwhelming that it's disgusting (and I hate black licorice). It's better with honey and I drink mine semi-warm so I can just chug it.

I went from only pumping half an ounce per side, to 1-2 ounces per side just after the first day of drinking it. The box suggests 3-5 cups a day but off one cup, my supply doubled.

So I strongly recommended this for any mom's struggling with their supply.