I had a large oversupply while I was breastfeeding and I was able to donate 10K plus ounces! I really attribute it to this hand pump. I started pumping at 37 weeks (cleared by my doctor) and I would pump with this hand pump after every feeding when my daughter was a newborn! It helped me create a stash for emergencies. 💛I love this hand pump and I would definitely recommend it. It’s also really great for pulling out that sticky colostrum. breastfeeding lactation milksupply