What do you think of the idea of magic being an unwanted side effect of mana?

A magic system I've had in mind is one of technological magic. Mana exists, and can be harvested, but people would rather do anything else than use it because of the way magic works. <br><br>Instead of magic being an end, it's really just a side effect of all the useful things that mana can do. Magic exists because of a quirk of humans and mana; when humans drink mana, they have to go through a process called "burn off," which is similar to when you go outside on a cold day and can see your breath. It's the same idea, where any leftover mana that the human didn't use has to be expelled from their body. Unfortunately for them, mana is invisible, so humans can only see this with magic sight. <br><br>The end result is that any time a person drinks mana and does anything, magic will happen. It could be anything from shadow creatures to hearing disembodied voices that don't exist to the air itself distorting as if there was a fire there. It's unpredictable, and the only way for a person to know what will happen if they drink mana is to drink mana. It varies by person and by substance, so there's always an element of danger in doing so.<br><br>As a result, humans would rather use magic substitutes than risk the side effects. Alchemy allows them to do the same or similar things to what mana does, but in a predictable way. <br><br>What do you think of this idea? There are a few stories I have in mind for it already, but I'd love to hear what you all think.