Today they can be found in every houses and shops and they are the drugs, the perfumes, the soaps, the creams, the make up kits and so on. They are not exactly the potions that we see in fantasy stories but it is important to know that most of them are derived from ancient recipes and elixirs made by spiritual leaders such as shamans, witch doctors and medicine men. Blinded by the world of today who tries to explain everything with science, it is easy to forget that even presented as a product, the effect of any concoctions can be much more effective if used properly. A part of this invisible power has already been acknowledged by the world of science and they call it the placebo effect.
Even if effective in their on right, products made by machines and mindless workers are likely to be less effective then those made with proper devotion. There is also the potions that cannot be found in a normal store like protection or love potions. With that said, anyone can make or find recipes to create their own concoctions or simply buy them from trustworthy sources.
A little warning
If a concoction is made or bought from an unknown party, it is very important to know its content and what it can do before ingestion. Even if every ingredients are edible, the mix of some of those could be dangerous. With that in mind, being careful and using safe combinations or doing some research on it first is the best way to go.
For more information about Potions and Elixirs, look at those web sites.