Easy DIY Remedies to Lighten Dark Armpits, Elbows and Knees! Today is the day I answer another one of your video requests, many people have asked me on social media for a remedy to lighten dark underarms, elbows and knees, so I compiled together a set of 5 natural remedies to resolve this issue. These remedies are easy to make and the ingredients are accessible from your fridge ! Ready to get started ?