Painkillers

 It makes you immune to damage until the numbness effect runs out and then administers some damage after the effect runs out. 

Stonecut bone to plasticine.

Melt plasticine into an empty pill shell (Sry cook time is 30secs will fix)

Make gelatin with kelp and a bowl.

Craft pill with gelatin, empty pill shell and a poppy

Eating pill will leave a shell

Eating pill too much crashes (will fix probably)