Single-drug lethal injection (pentobarbital)

This article explains how the method works at the level reported in court records and the news. It does not include doses or technical instructions.

Overview

In this method, a single drug, the barbiturate sedative pentobarbital, is used instead of a sequence of three drugs. It is the most widely used approach among states that carry out executions, and it is the method Texas, the state with the most executions since 1976, uses exclusively.

How it works

Pentobarbital is a sedative whose medical uses include treating seizures; it is also used to euthanise animals. In a very large dose it causes deep unconsciousness, then suppresses breathing and stops the heart. Because only one drug is used, there is no separate paralytic or heart-stopping drug.

How it is administered

The drug is given intravenously, through lines placed in the prisoner's veins. If the lines are not placed correctly, the drug can go into surrounding tissue instead of the bloodstream. Medical experts said this could explain Tennessee's failed attempt to execute Christa Pike on 30 September 2026, when she survived two doses.

What the prisoner may experience

Supporters of the method, including the Criminal Justice Legal Foundation, describe it as the most reliable option, and states say prisoners lose consciousness quickly. Critics point to autopsy studies that found fluid in the lungs (pulmonary oedema) of many prisoners executed with pentobarbital, which they argue can cause a sensation of drowning if it develops before the prisoner is fully unconscious. Witnesses at some executions have reported movement or apparent distress; in Christa Pike's case, she told witnesses her arm felt like it was about to burst.

How long it takes

There is no single figure. In most reported executions, the prisoner has been pronounced dead within minutes to under half an hour. When something goes wrong with the IV lines, it can take much longer or fail altogether, as in Tennessee in 2026.

Cost

Pentobarbital has become very expensive for states, because manufacturers refuse to supply it for executions and states must use other, secret sources. Public records show Texas spent more than $775,000 on pentobarbital between October 2024 and early 2026. Indiana has spent at least $1.275 million since 2024, including two doses costing $600,000 that expired without being used. In October 2026, Indiana released a $275,000 invoice for execution drugs.

Availability

Pentobarbital is difficult to obtain. Most states buy it from undisclosed sources, sometimes compounding pharmacies, which make their own versions that are not regulated by the US Food and Drug Administration. Secrecy laws in many states prevent the public from learning where the drug comes from, how much is held or when it expires.

Where it is used

States that authorise a single-drug pentobarbital protocol include Texas, Arizona, Tennessee, Indiana, Missouri, Georgia, Idaho, South Carolina, Louisiana, North Carolina and Utah, as well as the federal government. In 2026 it has been used in executions in Texas and Arizona, where Leroy Dean McGill was executed with pentobarbital in May. Tennessee used it in the failed attempt to execute Christa Pike, after which it paused all executions for the rest of the year.

Sources

1. Death Penalty Information Center: Texas spending on pentobarbital
2. Indiana Capital Chronicle: Indiana plans to proceed after Tennessee attempt
3. NBC News: Texas execution drug secrecy
4. NBC News: Christa Pike in critical condition after failed execution
5. WPLN: Tennessee moves to a single-drug protocol
6. medRxiv: autopsy findings of pulmonary oedema after lethal injection
7. Legal United States: drugs used in US executions (2026)