I swapped to the mooncup about 20 years ago. Tampons always made me feel unwell with worse period symptoms - draggy thigh pain, nausea, grim odour, vaginal ache, abdominal pressure on top of the usual period pain - I wanted to try something different that would also be better for the environment.
I was convinced within days that I had done the right thing. Yes, I still had the usual abdominal cramps but all the other symptoms never re-appeared. It was liberating.
I also never had leakage despite having heavier periods as I neared peri-menopause.
I put all my unpleasant symptoms down to the tampons. It’s really not that difficult to understand that these perfectly white bundles of cotton have been through so much chemical bleaching to get them the colour they are - there’s no way we should be putting them inside us.
I’ve bought moon cups over the years for all my family and friends - some I’ve managed to convert, some not. They don’t like the thought of using it but maybe reading the article linked above will help them decide.