NonyX Nail Gel breaks down and cleans out dark or yellowing keratin debris build-up under the nail. Once keratin debris is removed, nails look clear and attractive. Podiatrist recommended. NonyX Nail Gel is topical, safe, effective, diabetic friendly, all natural, money-back guaranteed. Millions of men and women face embarrassment from unsightly nails. Nail discoloration is actually keratin debris build-up under the nail. NonyX Nail Gel breaks down and removes this yellow or darkened build-up and keeps nails looking clear and attractive with regular use. Biodegradable. Not tested on animals.