Trainspotting is definitely not safe if you are squeamish.

I WILL LIST POTENTIAL PROBLEMATIC SCENES BELOW IN WHITE TEXT

I cannot recall any v* scenes but there are several graphic scenes such as severe d*, extremely dirty toilet although no v* is visible.
Renton falls in the toilet and crawls back out.
In the same toilet scene there is mild dry heaving.
He also prepares a room for his detox, such as a bowl for V* but he does not v.

I tried not to ruin the film, I managed to watch it all but just "skipped" that scene first time I watched alone. I watched it again with my other half and I felt braver.
It's an amazing piece of British cinema it'd be a crying shame to miss out on it. See if you can be strong, if not, just skip the scene!

Good luck, if you pluck up the courage to watch it let us know if you liked it.

Sadly for the other two I have zero insight >_<