Super Healing Potion

This is the last rung of the healing ladder and you will never have many. The ingredients are Lunar Fragments, so realistically you brew them in the gap between clearing the pillars and summoning the Moon Lord. The sickness that follows a drink lasts the same time whatever tier you swallowed, which is the whole argument for carrying these instead of Greater Healing Potions into a long fight. You get the same number of drinks either way, so each one should be worth as much as possible.

Build an Alchemy Table before you start brewing, because at this ingredient cost the chance of a refund adds up fast. If you break three pillars and leave the fourth standing, the fragments from the survivor can be converted into the other three kinds, which is how you go into the final fight with a full stack rather than a handful. Once the Moon Lord is dead and your gear is finished, leftover fragments have nowhere better to go anyway.

A Philosopher's Stone or a Charm of Myths cuts the wait between drinks, and at this point in the game that accessory slot usually earns its keep.