The only problem might be differences of opinion within each respective country.
For example, I know in Ireland that St John's Wort is a
Popular herbal medicine St John's Wort will remain available by prescription only, despite continuing calls for it to be sold in shops again.
From here irishhealth.com/article.html?level=4&id=384
But you can buy it without prescription in most E.U. countries.
I do not know if any things are prescription only in Poland that is not in other E.U. countries but I thought this difference was worth a mention.