Take biotin.

Do you bite them? If you do, don´t!

Put olive oil on them every night before you go to bed and wear cotton gloves over them. Also be sure to lotion your hands everyday. Dry nails crack.
I saw this woman with long nails and she told me to do this and it did work. Only after a while I really couldn’t stand the smell of olive oil. I couldn’t sleep with gloves on either so I would smell olive oil all night.

How to keep your fingernails healthy and strong

I have the exact opposite problem! My nails grow way too fast so it’s really hard to keep them short. I almost have to clip them every other day. I looked online for some ways to make them grow slower, and found out that the more blood flow you have in your fingers, the faster your nails grow. Also, the longer your fingers are, the more nutrients get to your nails. So with my long fingers, taking piano, and typing a lot, it makes my nails grow really fast. Maybe you could take a piano class or a typing course? It would give you a new skill and your nails would grow faster. Also take vitamins. I don’t know which vitamins since I’ve never had this problem, but apparently biotin is a good one.

I’m currently growing mine and I’m a picker, I find Sally Hanson, natural nail growth activator very good.

Gelatin capsules will do the trick. also, a good multi-vitamine will work. i take the vitamin and mine grow like crazy. just be sure to keep them away from your mouth and constantly biting them. john

Gelatin caps are now proven to be an urban myth, unfortunately.

I take a lot of vitamin D3, ground-up flaxseed and Omega-3 fish oil. My nails grow super-fast also.