Sidney Gottlieb used Atlanta prisoners for LSD-25 behavior tests

By Eleanor Voss · August 9, 2026

Prisoners in Atlanta were subjected to behavior-modification research for an illegal CIA program that still keeps the identity of certain chemical products blacked out.

On June 7, 1956, Sidney Gottlieb, Chief of the Technical Services Section of the Chemical Division, wrote a memorandum for the record. The document, as described in the National Security Archive's curated catalogue entry, authorizes an MKULTRA subproject led by Carl Pfeiffer of Emory University. Pfeiffer was a frequent collaborator with the agency who, according to the archival description, conducted experiments on prisoners at the federal penitentiary in Atlanta, Georgia.

In the memorandum, Gottlieb approves a request to continue Pfeiffer’s work, specifically the development of an "anti-interrogation drug" and the conduct of "tests in human volunteers."

"Tests in human volunteers"

The proposal attached to the memorandum identifies the study as "The Pharmacological Screening and Evaluation of Chemical Compounds Having Central Nervous System Activities." The archival description summarizes the objective of this screening as the testing of "materials capable of producing alterations in the human central nervous system which are reflected as alterations in human behavior."

This objective aligned with the broader scope of MKUltra, a program the public record identifies as an illegal CIA effort to develop procedures and drugs for altering human behavior. While the program is now widely condemned as a violation of individual rights and an abuse of power, the record from 1956 frames these activities as technical requirements for the Chemical Division.

The facilities required for Subproject 47, as noted in the redacted document, included "auxilliary [sic] animal testing laboratories" and facilities used for "preliminary human pharmacological testing." Crucially, the description notes further facilities "for testing in normal human volunteers at [deleted] Penitentiary directed by [deleted]."

Document imagery from nsarchive.gwu.edu From the files: nsarchive.gwu.edu

June 7, 1956

The memorandum outlines three particular projects for the coming year. The first was to "evaluate the effects of large doses of LSD-25 in normal human volunteers." The use of LSD-25 was a hallmark of the agency's behavior-modification research, often administered without the subject's informed consent—a practice that later became a focal point of congressional scrutiny.

The second project was to "evaluate the threshold dose levels in humans of a particular natural product to be supplied by [deleted]." The identity of this product and its source remain redacted in the archival description.

The third objective was more pragmatic in its pharmacological goal: to "evaluate in human beings a substance which we now believe has the ability to counteract the inebriating effects of ethyl alcohol." This suggests an interest not only in the induction of altered states but in the rapid reversal of impairment, a capability that would have held clear operational value for intelligence officers in the field.

The Atlanta Federal Penitentiary

The involvement of Carl Pfeiffer and the federal penitentiary in Atlanta highlights a recurring pattern in the MKUltra archives: the use of institutionalized populations. Prisoners, often marginalized or coerced, provided a controlled environment for pharmacological screening where the boundaries of consent were easily bypassed.

This specific subproject was part of a larger, fragmented network of research. Other files in the public record, such as those found in the Internet Archive's CIA Reading Room, describe similar efforts under Subproject 75 and Subproject 83, with dates spanning from the late 1950s into the early 1960s. These records collectively suggest a sustained effort to map the human central nervous system through chemical intervention.

The trail of Subproject 47 eventually led to the public sphere decades later. The National Security Archive's records include references to the 1975 Senate hearings held by the Select Committee to Study Governmental Operations With Respect to Intelligence Activities, where Sidney Gottlieb was called to testify. Those hearings, along with a 1963 report of inspection by CIA Inspector General John S. Earman, attempted to account for the scale of the MKULTRA/TSD operations after the program's internal records were largely destroyed.

Despite these later investigations, the 1956 memorandum remains a snapshot of the program's operational logic. It captures a moment where the pursuit of an "anti-interrogation drug" was treated as a standard budgetary and administrative matter, authorized with a simple memo for the record.

The record leaves the identity of the "particular natural product" to be supplied by a redacted source, as well as the specific identity of the penitentiary in the primary document, unmarked.