Throughout history, some of medicine’s most intriguing and groundbreaking discoveries have come from one fearless source: the scientist’s own body. Self-experimentation—a practice both daring and controversial—has played a pivotal role in unraveling the mysteries of human health, sometimes at great personal risk.
The Origins: When Doctors Tasted Urine
Long before modern laboratories, ancient physicians relied on direct sensory investigation. Hippocrates, often called the “father of medicine,” noted symptoms of what we now recognize as diabetes mellitus—excessive thirst, frequent urination, and weight loss. To confirm his suspicions, he tasted patients’ urine to detect its sweetness, a hallmark of the disease. This practice was echoed by the ancient Indian healer Shushruta, who described diabetic urine as “madhumeha” or honey urine.
Fast forward to the 17th century, British physician Thomas Willis famously dubbed diabetes the “pissing evil” yet also commented on the “wonderfully sweet” taste of diabetic urine. While the notion of sampling patient urine may raise eyebrows today, it stands as an early testament to the lengths medical pioneers went to understand disease firsthand.
The Agony and Ecstasy of Self-Experimentation
Medical self-experimentation has yielded invaluable insights, though it’s a path fraught with risk. One of the most celebrated examples is Barry Marshall’s groundbreaking work in the 1980s. Struggling to prove that the bacterium Helicobacter pylori caused stomach ulcers, Marshall famously drank a solution containing the bacteria himself. He soon developed gastritis, confirming the connection that revolutionized ulcer treatment and earned him a Nobel Prize in 2005.
Other researchers have followed similar brave paths, deliberately infecting themselves with pathogens like cholera, campylobacter, and yellow fever to study disease mechanisms and transmission.
Self-experimentation extends beyond infectious diseases. In the 1940s, Swedish chemists Nils Löfgren and Bengt Lundqvist developed lidocaine, a local anesthetic that transformed surgery by numbing specific areas without general anesthesia. Lundqvist tested this compound on himself before widespread use.
Then there’s Alexander Shulgin, the chemist behind the psychoactive drug MDMA (ecstasy). Known as “the godfather of ecstasy,” Shulgin meticulously self-tested new compounds to understand their effects before introducing them to therapists for psychological use.
The Hits and Misses of Self-Testing
Not all self-experiments have been successful. French researcher Daniel Zagury’s attempt to test an AIDS vaccine on himself and volunteers was ultimately unsuccessful. However, even in failure, such trials contribute valuable knowledge.
Accidental discoveries also highlight the unpredictable nature of self-experimentation. A Danish team testing a new antimicrobial medication found it caused adverse reactions with alcohol, leading to the development of disulfiram, a drug now widely used to treat alcohol dependence.
Victorian physiologist Joseph Barcroft stands out as a prolific self-experimenter, exploring the effects of cyanide gas, oxygenation in extreme environments, and hypothermia—all on himself.
Modern-Day Courage: Dr. Michael Mosley’s Journey
Fast forward to recent times, and Dr. Michael Mosley exemplifies the spirit of self-experimentation. Known for his engaging science presentations, Mosley went beyond theory by putting himself through extraordinary tests—including swallowing tapeworm larvae in 2014 to study their effects on the human body.
Tapeworms, notoriously marketed as a weight-loss gimmick for over a century, were shown to be ineffective as Mosley actually gained weight during the experiment. His willingness to endure such discomfort speaks volumes about his commitment to science.
Mosley’s advocacy for intermittent fasting and the 5:2 diet came from firsthand experience, with research suggesting benefits for weight loss and even reversing type 2 diabetes in some cases. His work continues a long tradition of researchers who have dared to be their own test subjects.
Why Self-Experimentation Matters
Despite ethical debates, self-experimentation has been instrumental in shaping modern medicine. From ancient urine tasting to contemporary diet trials, this hands-on approach allows scientists to observe effects directly and rapidly, often in ways that conventional studies cannot.
It’s a practice built on curiosity, courage, and a touch of audacity—pushing the boundaries of what we know by putting the scientist’s body on the line.
Dan Baumgardt is a clinical neuroscientist and anatomist at the University of Bristol. This article was adapted from The Conversation, an independent nonprofit dedicated to sharing expert knowledge.
