The Horrific zi Experiments on Women in Ravensbrück

In July 1942, inside the improvised operating room of the Ravensbrück concentration camp, a 21-year-old Polish woman was anesthetized without her consent and cut open in her left leg from the knee to the thigh. The doctor who operated on her cleaned the wound, inserted soil, wood shavings, pieces of glass, and a live culture of gas gangrene bacteria, then stitched the skin shut over it. The woman’s name was Władysława Karolewska, and when she woke up, her leg was burning from the inside.

Around her, in beds lined up with German precision, other women were suffering the same thing. It had not been an accident, but a calculated protocol. Ravensbrück was never a camp like the others; built in 1938 on the shores of Lake Schwedt, 80 kilometers north of Berlin, it was designed from the ground up with the specific function to concentrate, classify, and exploit women. It was the first of its kind in the Reich, and the SS, having learned from Dachau, Buchenwald, and Sachsenhausen, transferred their systematic model into a female universe.

The camp opened in May 1939 with fewer than 900 prisoners housed in clean, newly built barracks that smelled of fresh wood. The visual order was perfect, but what existed inside that order was something else entirely. By 1944, more than 50,000 women were crammed into facilities built for a tenth of that number. Over the course of its existence, between 120,000 and 132,000 women from more than 40 countries passed through its barbed wire, and at least 50,000 died there.

The exact figures remain a matter of debate among historians because the SS destroyed much of the documentation in the days before the evacuation, burning files that had recorded years of meticulous accounting of death. What happened in that camp between 1942 and 1945 was not a spontaneous aberration. It was a program with superiors, a budget, written protocols, and results documented in reports printed on official SS letterhead, leaving victims who had to spend decades convincing the world that their suffering had truly occurred.

Before the doctors arrived, Ravensbrück already had its own machinery of daily destruction. Women entered the camp stripped of everything—their names, their clothes, their hair, and their personal histories. They received a number sewn onto a blue and gray striped uniform, and the first to arrive in the convoy of May 1939 were German women—communists, social democrats, Jehovah’s Witnesses, women labeled as “asocial,” forced prostitutes from the penal system, and Sinti and Roma women.

The N4zis had classified these women with different colored triangles sewn next to their numbers: red for political prisoners, black for asocials, purple for Jehovah’s Witnesses, and green for common criminals. The taxonomy was exhaustive and functioned as a map of internal hierarchies that the SS deliberately cultivated. If the different groups hated one another, they were less likely to organize together, maintaining the fractured environment the SS required.

Then came the Polish women during the first months of the war, followed by French women after the fall of Paris, Czechs, Soviets, Dutch, Norwegians, Belgians, and Yugoslavs. By 1943, Ravensbrück was an involuntary city of 40 nations, where the common denominator was the striped uniform and the number sewn into the fabric. The camp had a strict internal hierarchy, with SS officers at the top and female guards, or Aufseherinnen, recruited from the German civilian population.

It is estimated that around 3,500 Aufseherinnen passed through Ravensbrück, coming from different social backgrounds—former seamstresses, housewives, and factory workers. They received three weeks of training and then assumed control of the barracks. Some were indifferent, some were cruel in a calculated way, and a very small minority occasionally helped prisoners when they could, but most occupied the broad territory between those extremes, participating in a system of sustained violence without needing a special motivation for each act.

Above them all, the commandant Fritz Suhren, appointed in 1942, was an orderly and cold man who administered the camp with an efficiency his superiors praised. Suhren did not display visible outbursts of cruelty; his brutality was bureaucratic. He gathered figures, assessed productivity, and signed execution orders with the same hand he used to approve supply requests. That administrative normality was precisely what made the scale of the horror possible.

Forced labor was the axis of life in the camp. Prisoners worked in the textile factory adjacent to the compound, producing uniforms for the Wehrmacht, as well as in construction, agriculture, swamp drainage, and the production of armament parts. The weakest were assigned to punishment commandos, where the physical burden was calculated to destroy them within weeks. Those who could no longer work were sent to the infirmary, and once that became useless, they were sent to Uckermark.

Uckermark was a satellite camp a few kilometers away where the selection process for the gas chamber and shootings operated with sinister regularity. Although officially classified as a youth camp, that was an administrative fiction; the women sent there did not return. Food was deliberately insufficient, and rations varied according to the labor value assigned to each prisoner, but in no case did they cover the caloric expenditure of a day of forced labor.

Chronic hunger weakened immune systems, making women vulnerable to the diseases circulating through the overcrowded barracks and accelerating the cycle of physical deterioration. The weakest bodies rotated out more quickly, making room for new arrivals in a logistics of human consumption that operated with the efficiency of a system that did not have to answer to anyone. Yet, extermination through exhaustion was not the only purpose.

In Berlin, the SS and the Reich’s medical apparatus had noticed that Ravensbrück contained tens of thousands of bodies that the state already considered discarded. They realized these bodies could be used before death to solve problems German medicine still had pending, specifically concerning thousands of soldiers dying of sepsis on the front lines. Battlefield soil, especially in regions where previous wars had been fought, was loaded with spores of Clostridium perfringens, the bacterium that causes gas gangrene.

Shrapnel and bullet wounds became infected, and surgeons observed with horror how toxins destroyed muscle from within. While sulfonamide antibiotics had existed since the 1930s, under frontline conditions with dirty wounds, no one knew with certainty how effective they truly were. What was needed was a controlled environment where a clean wound could be contaminated with specific bacterial agents in calculated quantities, and the concentration camp offered exactly that.

Karl Gebhardt was the man who organized it. An SS doctor, chief surgeon at the SS hospital in Hohenlychen, and Heinrich Himmler’s personal physician, Gebhardt was a trusted figure at the highest levels of the apparatus. Born in 1897 into a family of doctors, he had built a career in orthopedic surgery and headed the German Olympic medical team in 1936. By 1942, he was 44 years old and facing a political problem with potentially lethal consequences.

Reinhard Heydrich, head of the Gestapo and one of the principal architects of the final solution, had been wounded in Prague in May 1942. Gebhardt was summoned to treat him and made a decision that would mark the rest of his life: he did not administer sulfonamides. When Heydrich died of sepsis shortly after, political tension fell on Gebhardt. He needed to prove his clinical decision had been correct by demonstrating that sulfonamides would not have saved Heydrich anyway.

For that, he needed data that could only be produced by conducting an experiment under conditions that reproduced Heydrich’s wounds. Himmler gave him permission in June 1942, and the following month, Gebhardt and his assistant, Fritz Fischer, arrived at Ravensbrück to begin selecting prisoners. They looked for young, physically strong women capable of surviving the initial surgery long enough for the experiment to produce usable data.

The chosen women were mostly Polish political prisoners who possessed a remarkable internal cohesion. They shared a language, a history, and bonds of solidarity built during weeks of transit and months of communal life. This cohesion would prove critical for their survival and for the resistance that emerged within the camp. They were between 16 and 40 years old, ranging from nurses and university students to peasants and city workers.

The procedure was chillingly systematic. The woman was taken to the infirmary and anesthetized. The surgeon exposed the muscle, inserted agents like soil, wood shavings, ground glass, or gas gangrene bacteria, and in many cases, ligated the femoral or popliteal artery to simulate the hypoxia of a shrapnel wound. The wound was then stitched shut, and the woman woke up with a severe infection already progressing inside her.

Some women received different sulfonamide regimens in varying doses, while others received nothing as part of the control group. The untreated women suffered the most, dying of fulminating sepsis and progressive gangrene with fevers that destroyed organs within days. Those who received medication had a greater chance of surviving the acute phase but rarely emerged intact, as necrotic tissue left deep cavities in the muscle and bones were often partially destroyed.

Władysława Karolewska survived three experimental operations over several months, with each surgery leaving her with a severe, permanent limp. The sulfonamide experiments were conducted in successive batches from July 1942 until September 1943. Historians identify at least six different series, performed on at least 75 women, although some records suggest the number was higher. The data were reviewed by Gebhardt and presented as a lecture at the SS police and physicians conference in May 1943.

Not a single person in that room asked a question about the women who had produced the data. Gebhardt’s conclusion—that antibiotics were not the decisive factor when wound conditions were poor—was exactly what he needed to retroactively justify his decision with Heydrich. While Gebhardt managed his infection protocols, another group of researchers, led by Ludwig Stumpfegger, began experiments with broader implications for wartime reconstructive medicine.

Stumpfegger, an SS surgeon with direct links to Himmler, developed an interest in bone tissue transplants. No one knew with certainty whether it was possible to transplant bone tissue from one body to another and have it survive. In Ravensbrück, bodies were available to find out. The method involved surgically removing fragments of bone, usually from the tibia or fibula, from a prisoner and implanting them into other prisoners or German soldiers wounded at the front.

The donor lost part of her skeleton, and the recipient usually suffered as the immune system attacked the foreign tissue. The consequences for the donors were devastating: necrosis, deep infections, permanent limps, and loss of function in the foot or knee. Muscle transplants followed a similar logic but resulted in fibrotic tissue that lost the ability to contract, leaving the donor with a permanent muscular defect.

Peripheral nerve experiments were technically the most brutal. A segment of the sciatic nerve was removed from one prisoner and implanted into another to observe if it would regenerate or transmit electrical signals. The neurological complications were permanent in every documented case, with some prisoners losing sensation in entire limbs or developing severe, treatment-resistant neuropathy.

The prisoners were merely instruments, and the result was one more disability added to the other violences of the camp. In the barracks, the other prisoners watched. The Polish women coined the name Kaninchen—”little rabbits”—adapted from the German Versuchskaninchen, meaning laboratory animal. The term had brutal precision and created a collective identity, allowing the women to protect one another and share information about when the doctors arrived.

The strategies of resistance were limited but real. When the SS arrived with a list of names, other prisoners would hide the selected women in false bottoms of straw mattresses or in the barracks of other nationalities. They could not stop the experiments, but they could delay them, and every day of delay was time in which the selected woman remained whole. Polish prisoners trained as nurses also practiced clandestine care, assessing wounds without instruments or medication.

They also organized a secret record-keeping system. Several women kept lists of names, dates, and procedures, hidden in hollowed-out shoe heels or written on tiny scraps of paper folded to the size of a coin. Wanda Półtawska is one of the most documented testimonies. Arrested in 1941 for her resistance activities, she was operated on four times and survived, later becoming a psychiatrist who specialized in treating psychological trauma in war survivors.

The Kaninchen also tried to smuggle information out of the camp in messages hidden in clothing or transmitted orally to prisoners being released. The Polish government in exile in London began receiving these reports in 1943, but the response from Allied governments was minimal, as Ravensbrück remained a remote point on a map filled with more visible catastrophes. Meanwhile, other doctors arrived at the camp with different, equally horrific agendas.

Carl Clauberg, a gynecologist, was tasked by Himmler with developing a method of mass sterilization that could be applied to millions of Slavic and Jewish women at minimal cost. Clauberg experimented with intrauterine injections of caustic substances, including diluted acids, silver nitrate, and formalin-based compounds. The procedures were performed without anesthesia, and the women were awake while the injections were carried out, resulting in permanent sterility, severe pelvic infections, or death.

Horst Schumann arrived with a different method: the irradiation of reproductive organs with massive doses of X-rays. Patients were exposed for several minutes to radiation doses hundreds of times higher than what would be considered tolerable, causing serious radiation burns, tissue necrosis, and recurrent abdominal infections. Schumann documented that the method worked, but the level of collateral damage made mass application unfeasible, yet he continued anyway for months.

Herta Oberheuser occupied a singular place in the history of the camp as the only female doctor who actively worked in the experiments. She supervised the sulfonamide trials and participated in the selections, but her darkest role was administering lethal injections of paraffin oil or Evipan directly into the heart to eliminate prisoners who had become witnesses. She removed organs or limbs from bodies to preserve them as research material, acting with a bureaucratic normality that reflected the system’s inherent horror.

Dr. Fritz Fischer, Gebhardt’s assistant, took operational control of many procedures in the second phase. His surgical notes were detailed and clinical, describing tissues and physiological parameters with the same neutral tone he would have used in a university hospital. The medicine practiced at Ravensbrück was neither primitive nor improvised; it was technically correct but completely severed from the idea of healing.

By late 1943, the Kaninchen faced the threat of liquidation. The SS, fearing the survivors would be evidence of their crimes, wanted to eliminate them. When the SS arrived at the barracks with a list, hundreds of prisoners from different nationalities formed a human mass, making it impossible for the guards to extract the victims without causing a scene that would require explanations. The SS, valuing their bureaucratic efficiency, postponed the liquidation repeatedly.

In 1944, the Soviet advance began changing the priorities of the camp. Thousands of women arrived from Auschwitz and other subcamps, causing the camp to collapse in terms of space and sanitary conditions. Typhus and dysentery proliferated, and in the autumn of 1944, the SS decided to build a gas chamber inside the camp. It was put into operation in January 1945, and between then and the end of April, between 5,000 and 6,000 women were murdered there.

In mid-April 1945, Himmler attempted to negotiate with the Allies through the International Red Cross, offering to release some prisoners. While the political negotiation failed, the White Buses operation successfully evacuated Scandinavian prisoners. Some of the Kaninchen were among those able to board, while others were too sick to move and had to wait for the Soviets to arrive on April 30, 1945.

The documentation of the crime began before the war even ended. Polish survivors who reached Sweden gave statements to doctors, who photographed their scars with clinical precision. These images were evidence of a crime, and they would later become central to the Nuremberg Trials. The Doctors’ Trial, which began in December 1946, was the first time an international tribunal judged medical crimes as crimes against humanity.

The Kaninchen testified, with Władysława Karolewska and Jadwiga Dzido taking the stand to show the tribunal their scars. The images of their bodies were reproduced in newspapers around the world, providing direct physical evidence of the horrors. Gebhardt did not deny the experiments but argued they were justified by military necessity and that the victims were criminals who were going to die anyway.

The prosecutors, however, dismantled his arguments, establishing that the prisoners were political captives and that consent is a fundamental condition for medical ethics. The verdict reached on August 20, 1947, sentenced Gebhardt and others to death, while Oberheuser received a 20-year prison sentence. She was released in 1952 and resumed her career as a family doctor until a survivor recognized her in 1958, leading to the revocation of her license.

The Nuremberg process produced the Nuremberg Code, which established ten principles for biomedical research, starting with the requirement for voluntary consent. These principles transformed medical practice worldwide, becoming the foundation for the Declaration of Helsinki and modern regulatory frameworks. The chain of ethical consequences reaches directly to every informed consent form signed today in hospitals across the globe.

The survivors lived the rest of their lives with marked bodies, chronic pain, and the heavy burden of being witnesses to a crime the world took years to fully understand. Reparations negotiations were complicated by the Cold War, and many victims never felt the outcomes were just. Historical research on Ravensbrück accelerated after the fall of the Berlin Wall, with the opening of Soviet archives providing invaluable documentation.

Today, the Ravensbrück Memorial receives over 120,000 visitors a year. In the museum, display cases hold recovered objects and documents that detail the statistical data tables and clinical conclusions written in the neutral prose of scientific reporting. A specific room is dedicated to the Kaninchen, documenting their names, photographs, and the scars that served as evidence of the crimes.

Archaeologists who worked at the site in the 2000s found bone remains with surgical marks—tibia bones with clean, precise cuts that demonstrate the geometry of a surgeon’s saw. Decades after they were buried, these bones still speak of the violence committed against them. Bone preserves the evidence when paper deteriorates and memory erodes.

The story of Ravensbrück serves as a permanent reference for the floor of what cannot happen in medicine. It reminds us that horror does not require monsters, but rather ordinary employees who do what is expected of them without questioning the ethics of their actions. The Kaninchen understood that memory does not sustain itself and that it requires active, repeated work in each generation.

They traveled to conferences, wrote memoirs, and stood in the courtyard where they had been selected, carrying the weight of their experience. They did this because the alternative—silence—was a victory for those who committed the crimes. Through their testimonies and the documents preserved by the tribunal, the world learned what had been done in that forest clearing north of Berlin.

Lake Schwedt is still there, still among the pines, and the water remembers nothing. However, the archives, the testimonies, the bones in the earth, and the ethical principles governing modern medicine remember. The legacy of the 75 Polish women who woke up with their legs burning in the barracks is a testament to the fact that their voices and their pain could not be erased by the machinery of the camp.

To understand how it was possible for trained doctors to do what they did, one must look at the state of German medicine in the decades leading up to the war. By the 1920s, German medicine was among the most advanced in the world, but it had also embraced a radical form of eugenics—racial hygiene—which advocated for state-mandated intervention in human reproduction.

In 1933, the Nazi government passed the Law for the Prevention of Hereditarily Diseased Offspring, which led to the forced sterilization of over 400,000 people. This previous infrastructure normalized medical intervention on “inferior” populations, meaning the doctors at Ravensbrück did not cross a single invisible border into crime; they followed a slope that had been descending for years.

There is no record of any German doctor publicly denouncing the experiments during the regime’s twelve years. The medical profession, including its prestigious associations, was entirely integrated into the state apparatus. Silence was the institutional position, and the Doctors’ Trial addressed this collusion, establishing that professional obligations to the patient are higher than any state authority or chain of command.

That distinction was new in international law in 1947, as there had never been a need to explicitly define it before. Ravensbrück created that need. The women who testified knew their story was about more than their own experience; it was about the norms required to prevent such atrocities from happening again. That question remains a vital, ongoing struggle in the history of science and ethics.

Even in the decades that followed, the lessons of Nuremberg were sometimes ignored, such as in the Tuskegee Study, where researchers used the same mechanism of exemption to exclude their subjects from the protections of the code. The fact that the attempts to prevent such crimes did not always succeed does not invalidate the Nuremberg process; it makes it more necessary than ever to hold researchers accountable.

In the museum at Ravensbrück, there is a phrase from Jadwiga Dzido, who explained why she testified: if she did not tell the story, no one would, and the perpetrators would claim it never happened. She was right about the risk of denial, which persisted for years as defeated Germany tried to rebuild. The Kaninchen were the ones who ensured the memory of the crime was not lost.

They spent their lives working to ensure the world would remember, even when it was painful to do so. They were an international, multilingual network of women who supported one another, shared information, and kept the testimonies alive. Their determination is the reason we have the records, the photos, and the clear understanding of what occurred within the camp’s operating rooms.

The physical marks on their bodies never disappeared, acting as living documents of the cruelty they endured. Fractured bones and removed nerves remained part of them until they passed away, with the last original Kaninchen dying in the 1990s. With their passing, the direct link disappeared, but the evidence they provided remains an indelible part of history.

Lake Schwedt is still there, still among the pines, and the water remembers nothing, but it does not need to. Memory is kept by the archives and by those who read the records, study the bones, and uphold the principles written in the Nuremberg Code. The story of those women is not merely a tale of survival; it is a permanent warning about the fragility of human ethics when science is stripped of its purpose.

In the end, the history of the Kaninchen is a history of resistance, a struggle against a system that intended to turn human beings into mere raw material. By telling their stories, they reclaimed their humanity and forced the world to bear witness to the crimes of the SS doctors. Their persistence serves as a bridge to our own time, forcing us to grapple with the moral responsibilities inherent in the practice of medicine and the study of human life.

The world would be a darker place without the testimony of those 75 Polish women. Because they survived, because they refused to be silent, and because they dared to confront their captors in the halls of justice, we have a clear map of the atrocities committed in that forest clearing. They transformed their own suffering into a set of principles that protect human dignity in laboratories and hospitals across the entire world today.

The scars, the bones, the reports, and the records all speak to the same truth: history is not just what is written by the victors; it is what is documented by the victims, even when the state tries to burn every scrap of paper. The Kaninchen were the guardians of that truth. Their lives were interrupted, their bodies were broken, but their spirits ensured that the world would never be able to claim it did not know what happened at Ravensbrück.

Today, as we look back on the 20th century, the story of Ravensbrück stands as a testament to both the depths of human depravity and the height of human resilience. It is a story that must be retold, not out of a desire to dwell in horror, but to honor those who survived and to safeguard the fundamental rights that were won at such a devastatingly high price.

The pines continue to rustle around the shores of Lake Schwedt, witnessing the passage of time and the arrival of new generations who come to learn the history of the camp. The landscape itself has healed, but the documents remain, silent yet powerful reminders of a time when the world was pushed to the brink of losing its moral compass.

We owe it to the Kaninchen to keep reading, to keep researching, and to keep defending the principles they fought to establish. Their story is a cornerstone of our collective understanding of human rights, a reminder that the cost of inaction is too high and that the pursuit of truth is an essential, never-ending labor for all of humanity.

As we move further into the future, the physical memory of the Kaninchen may fade, but the ethics they catalyzed will continue to shape the way we approach science and medical progress. They were the victims of a monstrous machine, yet they were also the architects of a safer, more ethical world. Their courage in the face of absolute despair remains an inspiration to anyone who values justice and truth above the silence of complicity.