Does jello make nail hard

Answer 1

No, it does not. And neither does Gelatin. From Wikipedia:

"For decades, gelatin has been touted as a good source of protein. It has also been said to strengthen nails and hair. However, there is little scientific evidence to support such an assertion, one which may be traced back to Knox's revolutionary marketing techniques of the 1890s, when it was advertised that gelatin contains protein and that lack of protein causes dry, deformed nails. In fact, the human body itself produces abundant amounts of the proteins found in gelatin. Furthermore, dry nails are usually due to a lack of moisture, not protein."

One thing that does help is Biotin supplements. A group of Swiss researchers has demonstrated that use of Biotin supplements increased the thickness of nails by an average of 20% among participants of a recent study.

A well-balanced diet is also important for healthy hair, skin, and nails.

Answer 2

The gelatin in Jell-O is what makes it harden. Gelatin is made from the collagen in various animal by-products such as skin, bones, and connective tissues.