Many potions require specialist handling

"Potion" really represents a huge category of things, like "chemicals" or "drugs". A number of potions are generally safe to use with minimal warnings and are shelf-stable and these are sold by mega-corporations cheaply and in bulk to the public. However, then there's the rest of them...

• By analogy with certain specialized medicines, some potions have a very short shelf-life or require special storage conditions and so require a trained witch locally to prepare them immediately before use.
• By analogy with pesticides and explosives, some potions require specialist knowledge to use correctly and safely apply requiring a trained and licensed witch locally to use.
• By analogy with controlled substances or weapons, some potions have the potential for abuse (e.g. love potions, curses) and so only can be sold in-person from a licensed witch.

Many potions require specialist handling

"Potion" really represents a huge category of things, like "chemicals" or "drugs". A number of potions are generally safe to use with minimal warnings and are shelf-stable and these are sold by mega-corporations cheaply and in bulk to the public. However, then there's the rest of them...

• By analogy with certain specialized medicines, some potions have a very short shelf-life or require special storage conditions and so require a trained witch locally to prepare them immediately before use.
• By analogy with pesticides and explosives, some potions require specialist knowledge to use correctly and safely, requiring a trained and licensed witch locally to use.
• By analogy with controlled substances or weapons, some potions have the potential for abuse (e.g. love potions, curses) and so only can be sold in-person from a licensed witch.