I recommend Dancing Whale Slim Medium sanitary pads.

I used to have a lot of impurities and struggled with menstrual cramps. After the controversy regarding harmful substances in sanitary pads came out on the news, I realized I couldn't just use any product. So, I tried all kinds of pads before finally settling on this one. It has great absorbency, and since using "Dancing Whale," there are definitely almost no impurities!! It was really amazing. Also, my menstrual cramps aren't severe, so I'm very satisfied with it!! It is certified as being free of harmful substances, so you can use it with peace of mind.