I know these potions were added with Muspel and I think they should be more widely available.
Currently, they're ONLY available in Muspel with quite a low chance to drop.
I don't think they're overpowered by any means, good for characters with low vit and helps them to stay somewhere for a bit longer than they usually can. White pots are hella expensive and don't heal much for those low vit characters.
They could be added to the NPC for an expensive amount (could be between 10-50k each) and act as a zeny sink for the server whilst also opening up more leveling options than just partying and specific locations or specific gears.
Whilst some may think that it replaces potions, potions aren't a viable option for those characters without much str or vit.