- Sodium thiopental: ultra-short action barbiturate, an anaesthetic agent capable of rendering the prisoner unconscious in a few seconds.
- Pancuronium: non-depolarizing muscle relaxant, causes complete, fast and sustained paralysis of the skeletal striated muscles, including the diaphragm and the rest of the respiratory muscles; this would eventually cause death by asphyxiation.
- Potassium chloride: stops the heart, and thus causes death by cardiac arrest.
Other drugs may apply in different countries or states.