I spend quite a bit of time looking at health related topics, but don't see the adverts you are talking about.
Firstly, check your sources. I suspect a bit of careful source selection will assist you.
Pick sources of information that are not, and will not be trying to sell product, such as recognised medical and academic institutions, or government organisations.
If you subscribe to emails or Facebook groups that are about promoting products, or rather do not exclude the promotion of products then you will get ads.
Secondly, on your browser use something like Adblock Plus, Privacy Badger, etc to stop ads appearing. Within Facebook I use Social Fixer which will stop ads and a lot of other junk within Facebook.