The Flask of Wondrous Physick is one of the most useful items in Elden Ring.
Alongside Flask of Crimson Tears and Flask of Cerulean Tears - which boost HP and FP respectively, and require Golden Seeds and Sacred Tears to upgrade - the Flask of Wondrous Physick can be customised by equipping Crystal Tears.
Unlike those Flasks, you have to find the Flask of Wondrous Physick location first. You'll want to head to the Third Church of Marika, which is thankfully, not far from the start of the game - though requires going into uncharted territory for those just starting out.
Elden Ring Third Church of Marika location for the Flask of Wondrous Physick
The flask of wondrous physick can be found in the starting region of Limgrave, although it will still require traversing beyond the starting area.
You'll find it at the Third Church of Marika in East Limgrave. Though you can head here right away, it's recommended you pick up both Limgrave Map Fragments to help you navigate the world a little easier.
To find the Third Church of Marika location, take the road north-west from Lake Agheel, or north of Mistwood.
Once there, at the altar of the statue you'll also find a Sacred Tear as well as your first Crystal Tear, the Crimson Crystal Tear, which restores half your total HP. The flask is in a large stone bowl on the ground nearby.
Once you have settled on a starting class and starting Keepsake item, you should first work out how to level up, how to respec and use Ashes of War. Need some direction from there? Try finding Golden Seeds, Sacred Tears, Crystal Tears, Talismans and some of our best weapon and best armor set choices. If you want to improve your prowess, then we recommend rune farming - especially before taking on Magrit, Godrick the Grafted, Crystalian, Leonine Misbegotten, Starscourge Radahn (required as part of the Ranni quest), Red Wolf of Radagon and Renalla Queen of the Full Moon after you have found the Glintstone Key location.
Once you have the Flask, rest at a Site of Grace and you will be able to select 'Mix Wondrous Physick' in the menu. This takes you to a screen showing all the Crystal Tears you have found. Up to two Crystal Tears can be mixed.
You'll find Crystal Tears primarily at Minor Erdtrees, some of which simply at the base, others after completing a battle against an Erdtree Avatar.
Like the other flasks, this is an item you'll also want to equip in your quick items for convenient use. Once you are ready to begin expanding what you can do with the Flask of Wondrous Physick, our best Crystal Tears explainer can help.