I tried tea tree oil but did not see any results; however, after several years of experimenting with different natural cures, had the most success with hydrogen peroxide. After bathing/showering, trimming your nails, and cleaning thoroughly underneath your nails: soak a Q-tip swab in hydrogen peroxide and apply liberally (all over) your affected nails, allowing the solution to soak underneath your nails as well. Be sure to allow your toenails to dry before donning socks or shoes and be careful not to get the peroxide on fabric or furniture-application at the bathroom sink works best for me. I also soak my nail trimmers, file, etc. in the peroxide for a few minutes after use. It took about 6 months for my nails to totally clear up, but it worked! I now use several times per week just for prevention. Hope it works for you too.