Why is needing recipe for remedies?

Am not bough a SYRUP against cough without a recipe,than earlier, that talked a remedy has codeine, but I think,that happening for analgesics.
Yes, here on summer we added such limited,as limited for selling drugs are caffeine, codelac, nospalginum, nurofen plus, solpadein, terpincod, as this happened,.that a drugs with codeine a very simple to cook a low price is narcotic, which is very dangerous.