Stimpak

Stimpaks are a popular healing chem. When injected, the chem provides immediate healing of minor wounds.

Superior versions of this chem (but with some drawbacks) are Super Stimpak and Ultra Stimpak.

Fallout, Fallout 2 and Fallout Tactics
In Fallout, Fallout 2 and Fallout Tactics, stimpaks can only restore Hit Points, but cannot heal crippled limbs.

In Fallout 2, Myron can make these if you give him the proper ingredients:
 * Empty Hypodermic
 * Xander Root
 * Broc Flower

Fallout 3
Unlike previous games, in Fallout 3 they can also be used on crippled limbs to heal them. "When used on a limb it heals most of the damage on the limb but very little on the whole body's HP, and when used on the whole body, the whole body's HP is healed, but limbs are healed very little. Because of this, the use of stimpack is fairly tactical."

Appearances
Stimpaks appear in all Fallout games, as well as in DOOM. Super Stimpaks appear in Fallout, Fallout 2, Fallout Tactics and Fallout: Brotherhood of Steel, while Ultra Stimpaks appear only in Fallout Tactics.