Nembutal Pentobarbital sodium solution is a short-acting barbiturate, chemically designated as sodium 5-ethyl-5-(1-methylbutyl) barbiturate. This is one of the reasons for being more suitable for suicide than longer-acting barbiturates such as phenobarbital.
Nembutal Pentobarbital sodium solution is a proven, reliable drug that brings about a peaceful death. Almost no failures are known, despite large statistics (for example, the Swiss euthanasia organisation Dignitas reported 840 exits with no single failure). There are however reports on seemingly slow or painful deaths with Nembutal in capital punishment, although this may be due to poor quality of the drug from compounding pharmacies given intravenously rather than orally.