I recommend Kerasel.

This is a nail care product containing Kerasel's signature ceramide and collagen. It enhances the moisture and elasticity of nails and prevents splitting and breakage. Apply once a day.

It is important to use nail strengtheners consistently for the health of your nails. You can see better results by adopting habits such as reducing stress, avoiding nail biting, and not cutting your nails too short while using the strengthener.