Hair is dead so once it splits, it is split. There is no way to heal it like you can with skin. All those 'clinical studies' that shampoo companies rave about how split ends were repaired are full of bunk. Most likely these studies only proved that split ends were less likely or that dry ends were given moisture, thus preventing a split.
The only way to get rid of a split end is to get your hair trimmed. From there you can do all kinds of things to prevent split ends, such as conditioning the tips of the hair well, avoiding heated styling products and even using coconut oil in the ends of the hair when it gets dry, but even with all that hair is still going to split sooner or later. Just keep it trimmed up when that happens.







