Alchemy is the aspect of magic closest to mundane science, and the only kind that can be performed by those without spellcasting or channeling ability. The ingredients required for most potions and elixirs make them impossible to mass-produce on a Cosmic scale. Rare herbs that can only be found on a few worlds (usually needing to be grown along magical ley lines) are the most basic ingredients. Even rarer components such as powdered gemstones and rare animal glands are required for more powerful elixirs.
Basic potions, such as healing and mana-restoring potions, are the most common, though medkits and other mundane means are more common ways of achieving some of the same effects. Other protective, restoring, enhancing, and mind-effecting elixirs can only be found in alchemical specialty stores. Only the greatest alchemists can produce the greatest wonders, such as the universal solvent Alkahest, homunculi, and the fabled Philosopher’s Stone. Arcane and divine magicians may become alchemists, but so may scientists, and many adventurers learn alchemy for their own use.