John Hunter - In the days before controlled clinical trials, many medical researchers used themselves as guinea pigs. Born in Scotland in 1728, John Hunter was a brilliant surgeon. He wrote two books on teeth, and is credited with naming the cuspids, bicuspids, incisors and molars. Upon damaging his Achilles tendon, he used dogs to show how bones and tendons mend. But his interests weren't limited to teeth and bones, and his wild experimentation wasn't limited to cutting the tendons of dogs to analyze the healing process. In writing his Treatise on Venereal Disease, Hunter inoculated himself with gonorrhea to study the course of the disease and response to treatments with mercury and cauterization. His studies added greatly to the understanding of the role of inflammation in healing. Unfortunately, sterile technique wasn't the practice of the day and the needle used to infect himself was also contaminated with syphilis. When he contracted both diseases, this was taken as proof that there was, in fact, only one venereal disease - an error that wouldn't be corrected for another half-century.
Lazzaro Spallanzani - While John Hunter was torturing his own genitals with STDs, his contemporary Lazzaro Spallanzani was playing with those of animals. His work described mammalian reproduction, and he was the first to perform an artificial insemination, using a dog as his subject. He also performed experiments testing ideas of spontaneous generation. His great self-experiment was a study of the digestive process, Dissertationi de Fisica Animale e Vegetale, published in the 1780s. These experiments were done using his own gastric acids either collected by induced vomiting, or, more dramatically by swallowing linen containers containing material to be digested. He would let them pass and find the bag intact, but the contents gone. To show it was a chemical and not mechanical action, he repeated these experiments with perforated metal or wooden tubes, allowing the food to be exposed to the stomach contents, but unable to be ground by mechanical action. He expanded the knowledge of digestion, making the disctintion between mechanical and chemical digestion and postulated the involvement of acid in the gastric juice.
Barry Marshall - If Spallanzani taught us about digestion, Barry Marshall taught us about indigestion. As a physician interested in gastritis he, along with Robin Warren, cultured Heliobacter pylori and hypothesized a bacterial cause for gastritis and peptic ulcer, going against the commonly held belief that spicy or acidic foods and stress were responsible for those ailments (as well as the belief that no bacteria could survive in stomach acid). In the face of overwhelming opposition to his ideas and lacking an animal model in which to test them, a healthy Marshall drank a pyloric culture and fell ill, eventually presenting with gastritis as predicted. By his own admission, Marshall was surprised by the severity of infection, never expecting to become as ill as he did. This experiment both demonstrated a bacterial cause for gastritis and peptic ulcers and laid the groundwork for a simple and cost effective treatment - antibiotics. Barry Marshall won the Nobel prize for his work in 2005.
Max Joeseph von Pettenkofer - Consumption of a pathogenic bacteria is a common theme among self-experimenters and 100 years before Barry Marshall gave himself an ulcer, Max Joeseph von Pettenkofer was performing similar experiments. Sometimes considered the father of epidemiology, von Pettenkofer was a strong proponent for hygeine for good health. In an attempt to prove that the bacteria alone would not cause cholera, but rather dependent on 7 factors (including diet and hygeine), he drank a cholera sample isolated from the excrement of a dying patient. Though he had mild symptoms, "light diarrhea with an enormous proliferation of the bacilli in the stools", he did not have a severe reaction and considered himself vindicated.
Jesse Lazear - Not every self-inoculation has such mild consequences. Jesse Lazear was a physician working in Cuba with the US Army Yellow Fever Commission. Faced with evidence of an intermediate host in the spread of yellow fever and familiar with mosquitoes and the transmission of malaria, Lazear wanted to get to the real vector. He began infecting mosquitoes in August 1900, and allowed himself to be bitten, eventually contracting the disease and dying. While he lost his life in this experiment, "his work contributed towards one of the greatest discoveries of the century, the results of which will be of invaluable benefit to mankind." (Dr. L.O. Howard) Currently Yellow Fever is mostly restricted to sub-Saharan Africa and developing countries in South America, and a vaccine against this infection exists.
William Harrington - Some researchers go to even greater lengths to make themselves ill than drinking a culture or being infected by mosquito. This was the case for William Harrington, a haemotologist in St. Louis. Trying to find a basis for idiopathic thromgocytopenic purpura (ITP), a disease resulting in a low platelet count which causes bruising, and bleeding issues, Harrington infused himself with plasma from a patient with ITP and rapidly developed transient thrombocytopenia, with a severe risk of hemmorhaging. His experiment demonstrated that there was a plasma factor responsible for the condition. Harrington's discovery of an autoimmune component has lead to a number of therapies for the disease.
Werner Forssmann - If blood transfusions and toxic cocktails aren't risky enough, then what about self-surgery? Werner Forssmann showed that the way to a man's heart is through the antecubital vein. At the time, the belief was that any entry into the heart would be fatal, but Forssmann inserted a catheter into his arm and threaded it 65 cm into his heart. He then walked to the radiology department, to have it x-rayed to prove his success. Over his lifetime, he would do this several more times, even using the method to inject solutions into the heart. (Forssmann's goal was to use this technique to directly administer drugs) Though he was fired from the hospital for his initial experiments, Forssman was recognized for his work, sharing the 1956 Nobel Prize for Medicine or Physiology.
Obviously there are many others who have risked life and limb through self-experimentation in pursuit of a breakthrough. Right or wrong, some of them have certainly lead to advancements in medical or other fields. How far would you go for your science?