Alright I have had friends, coworkers, and even family ask about glow in the dark in and what it is and if it is even healthy to use. From research and speaking to multiple artists from around my area I have come to a conclusion that as of right now, glow in the dark ink is one of the most dangerous inks to use and would not suggest.
Though it is visually pleasing, the formula that they use inside of these inks are mainly phosphorus which can be really dangerous to use on the skin due to the fact it is only activated in UV lighting. There is a concern in the community about developing skin cancer due to the ingredients are inside of the ink.
After doing some research, I have actually found out that big time celebrities such as Lil Wayne, Kim Kardashian, and Lindsay Lohan all have glow in the dark tattoos. Now as of a few years ago, this ink was not FDA approved which led to discussions about what it could do in the skin long term. As of recently though, there has been a formula made in which there is an absence of phosphorus but tattoo artists around my area in New Jersey have not recommended it because it has not been out too long and that they are still unsure of what effects it can cause.
Disclaimer: the photos above are not mine and were taken from other photographers and some of this information was found from http://blog.tat2x.com/glow-in-the-dark-tattoos-the-pros-and-cons/ if you want more information on them.