There is a sliver of truth to what Roy says. Some, but not all, sunscreens contain an ingredient called oxybenzone that can be absorbed by your skin and potentially cause problems:

Most doctors see no problem with it, but it's never a bad idea to avoid chemicals like that if there are alternatives that are just as effective (zinc).

To the OP, surfline has run a quite a few good articles about sunscreen over the last couple years. Easy to find through google.