The Troubling Origins of a Skincare Phenomenon
Prized for their powerful anti-ageing properties and promises of achieving flawless 'glass skin', potent vitamin-A skincare products known as retinoids have experienced a remarkable surge in popularity in recent years. However, one of the most effective of these treatments – prescription cream tretinoin – is connected to one of the most disturbing chapters in modern medical history.
The Controversial Creator
The prescription cream, widely celebrated today as the gold standard for both acne and anti-ageing treatments, was developed by American dermatologist Dr Albert Kligman. Yet many of the experiments that helped establish his professional reputation have since been condemned as among the most unethical in contemporary medicine.
Historical records reveal that Dr Kligman conducted extensive experiments on prisoners and vulnerable patients throughout the United States during the mid-20th century, deliberately exposing them to harsh chemicals, infectious agents, and toxic compounds. Some particularly disturbing studies reportedly involved intentionally infecting children with learning disabilities with fungal conditions including ringworm.
The Holmesburg Prison Experiments
Later trials conducted at Holmesburg Prison in Philadelphia – a facility so notorious for violence it was nicknamed 'the Terrordome' – exposed inmates, many of whom were poor or African American men, to substances including adhesives, radioactive compounds, mind-altering drugs, and industrial chemicals.
In a notorious 1966 interview, Dr Kligman described his initial reaction upon entering the prison: 'All I saw before me were acres of skin. I was like a farmer seeing a fertile field for the first time.'
While tretinoin itself was developed through conventional dermatology research, disturbing revelations about the work of its inventor continue to raise difficult questions about the ethical context in which some of the era's most influential skin research occurred.
Early Career and Institutional Experiments
Before his work at Holmesburg Prison expanded into a vast programme of human experimentation, Kligman had already built his early career studying infectious skin diseases in institutional settings. During the 1950s, he conducted dermatology research at the Pennhurst State School and Hospital, a large facility housing children and adults with intellectual disabilities.
According to historian Allen Hornblum's work Acres of Skin: Human Experiments at Holmesburg Prison and subsequent medical ethics analyses, some of these studies involved deliberately infecting children with dermatophyte fungi – the organisms responsible for causing ringworm. Researchers induced these infections, they claimed, to observe how the disease developed and to test potential antifungal treatments.
At that time, ringworm outbreaks were common in crowded institutions, schools, and military barracks. Scientists argued that inducing infections under controlled conditions would help them better understand disease transmission and treatment options. However, critics maintain that this research raised serious ethical concerns because the children involved were highly vulnerable and incapable of providing meaningful consent to participate.
Expansion into Prison Research
These early experiments helped establish Kligman's reputation as a dermatologist specialising in fungal infections – research that expanded dramatically when he began conducting trials on prisoners at Holmesburg Prison in Philadelphia.
According to medical ethics analyses and historical investigations, what began as a small dermatology project evolved into one of the largest programmes of human experimentation ever conducted in a United States prison. For more than two decades – from the early 1950s until the mid-1970s – inmates were used in hundreds of studies testing pharmaceuticals, cosmetics, industrial chemicals, and even substances linked to military research. Many of these projects received funding from private corporations or government agencies.
Specific Experiment Types
One of Dr Albert Kligman's earliest research projects involved deliberately infecting prisoners with fungal diseases such as ringworm and athlete's foot, mirroring his earlier work with disabled children. According to evidence examined by historian Allen Hornblum, large quantities of fungal organisms were applied to prisoners' skin, with their feet then wrapped or enclosed in boots or bandages to encourage infection before researchers tested different antifungal treatments. These infections could cause severe itching, rashes, and cracked skin.
Kligman also conducted studies in which inmates were infected with viruses affecting the skin, including herpes simplex. Researchers monitored infection development and used these outbreaks to test experimental treatments, with participants sometimes developing painful lesions and open sores during these experiments.
Perhaps the most notorious trials involved dioxin (TCDD) – an extremely toxic chemical later associated with the herbicide Agent Orange used during the Vietnam War. Between 1965 and 1966, Kligman conducted studies funded by the chemical company Dow to examine how this compound affected human skin. Prisoners had the chemical applied directly to their backs in patches or injected beneath the skin, with some developing chloracne – an agonising and disfiguring skin eruption caused by dioxin exposure. Later investigations revealed that some inmates had received far higher doses than originally planned.
Commercial and Military Testing
Kligman's laboratory also conducted hundreds of tests for commercial companies evaluating everyday products. Prisoners had substances repeatedly applied to their skin to determine whether they caused irritation, burns, or allergic reactions. These substances included skin creams, shampoos, hair dyes, detergents, deodorants, and experimental pharmaceutical drugs. Companies paid both the prison and research teams to carry out these trials.
Another set of experiments involved using radioactive tracers to study how human skin renews itself. Scientists applied or injected radioactive isotopes into small areas of skin and then tracked how labelled cells moved through epidermal layers – work that contributed to dermatologists' understanding of skin cell turnover.
Some research carried out at Holmesburg was also funded by the United States military. In these studies, inmates were exposed to chemicals designed to irritate or blister the skin so scientists could observe the effects, with participants sometimes reporting severe rashes and burns following exposure.
Ethical Concerns and Participant Exploitation
Historical analyses suggest that thousands of prisoners participated in experiments at Holmesburg between the 1950s and early 1970s. Inmates were typically paid small sums of money – sometimes only a few dollars – to participate. Critics argue that these payments exploited prisoners who had very few alternative ways to earn money while incarcerated.
Kligman and other researchers defended the work as legitimate medical science. Writing in the journal JAMA Dermatology in 2020, Dr Luke Adamson and bioethicist Dr Ezekiel Emanuel stated that Kligman 'saw prisoners as objects for experimentation'.
Kligman himself was quoted as saying about his time at Holmesburg: 'It was years before the authorities knew that I was conducting various studies on prisoner volunteers. Things were simpler then. Informed consent was unheard of. No one asked me what I was doing. It was a wonderful time.'
Scientific Justifications and Ethical Reforms
He argued that deliberately inducing fungal infections or viral outbreaks was necessary to understand how these diseases spread and responded to treatment. Chemical exposure studies were presented as a way to determine whether industrial compounds were safe for human use. Trials involving cosmetics, household products, and drugs were described as routine safety testing needed before products could be released to the public. Research using radioactive tracers was intended to improve scientific understanding of how skin grows and regenerates – knowledge that later helped shape treatments for acne and ageing.
Despite these explanations, the Holmesburg programme has since become one of the most heavily criticised episodes in modern dermatology. Dr Adamson and Dr Emanuel condemned the research, stating that it 'exploited a vulnerable population who could not freely refuse participation'. They noted that the prisoners used in the experiments were often poor, disproportionately black, and under significant financial pressure to take part.
Historian Allen Hornblum, whose investigation remains the most detailed account of the programme, described the studies as 'a classic example of how vulnerable populations can be exploited in the name of science'. Ethicists frequently compare Holmesburg with the Tuskegee syphilis study, another notorious United States medical scandal in which hundreds of Black men with syphilis were deliberately left untreated by government researchers for decades so scientists could observe the disease's progression.
Legacy and Lasting Impact
While representing an unarguably shameful episode in medical history, these controversies helped spur sweeping reforms in how medical research is conducted. In the years that followed, the United States Congress passed the National Research Act, which created the modern system of ethical oversight for research involving human participants.
Stricter rules were introduced requiring researchers to obtain fully informed consent from participants, limiting the use of prisoners and other vulnerable groups in experiments, and mandating independent oversight by institutional review boards to assess whether studies are ethical before they begin.
Today, the Holmesburg experiments are widely cited in bioethics literature as a warning of what can happen when scientific ambition outpaces ethical safeguards. Even the University of Pennsylvania, where Kligman spent much of his career, has acknowledged the episode as a painful chapter in its history and has funded research and community initiatives examining the lasting impact of the studies.
For many historians and ethicists, the legacy of Holmesburg serves as a powerful reminder that medical breakthroughs can sometimes emerge from deeply troubling circumstances – and that protecting the rights and dignity of research participants must remain at the very centre of scientific progress.
