When injected, a super stimpak heals 75 HP immediately, but the powerful nature of drugs used in the process will cause an adverse reaction from the organism, resulting in draining 9 HP after two minutes.
The super stimpak is a rare sight in the wasteland, usually only available from high tech settlements, such as Vault City or San Francisco.
Sometimes, chemistry geniuses can whip up a super stimpak, which is the case with Myron, who could create one from 1 stimpak, 1 Nuka-Cola and 1 fruit or a medically-inclined player character. (76% Doctor skill or more).
Five are found inside of an ice chest located in the room where Dr. Wu is located in The Cathedral's interior. This ice chest is locked, however, and must be lock picked in order to open it. In the higher levels of The Cathedral, Morpheus possesses one super stimpak.