There are some potential side effects found in animal models, but they're either incredibly weak or only seen in conditions not really comparable to 5G. I looked at some of the studies in one of these 5G protest sites and a huge amount of data cited was about LF magnetic fields which really have nothing to do with 5G.

We're talking about daily 24/24 exposure for the rest of your life. I don't think we can put 3 mice in a cage, blast them for 3 hours and declare that it only had a weak effect = it's safe.

We added lead to car fuel to improve performances and told people it was safe for decades, we're still paying the price of that mistake today.