Does vegan tattoo ink last forever on skin?!
Answers: just like regular tattoo ink does?
If you are talking about "henna," it lasts for approximately 7 to 10 days, depending on your hygiene.
If you are talking about "Stable" brand tattoo ink, the only difference between their ink and regular tattoo ink is the glycerin. The glycerin is derived from plant oils, not animal oils, so yes, it is permanent.
So far Stable is the only tattoo ink that makes an effort to make Vegan friendly inks (oddly I am not a vegan, yet I am fully aware of this).
I am glad you are thinking this far, as to avoid the animal products in your tattoos, as well.
vegan tattoo ink is just the same, but different ingredients, it MAY fade a tiny bit faster, but it will always be there.