Yes, the nails always grow back only if the matrix is not badly damaged. If you lose your entire fingernail, it may take up to 4 to 6 months for it to regrow. However, the toenail can take up to one and a half years to regrow. The growth of nails is dependent on age, location, hormones, and gender. If you have lost your nail, talk to your doctor to know how long will it take for the nail to grow back and how you can protect the area while this is happening.