In the early 1980s, Young briefly studied therapeutic massage, although he did not complete a course of study. In 1982, Young opened a clinic in Spokane, Washington, which offered unlicensed medical services, including childbirth. In early 1983 when Young was 33 years old, an undercover Washington State police officer approached Young about performing an underwater birth, as part of an effort to "police all registered professions". Young reportedly offered to provide prenatal services, and treat the cancer of the officer's mother, and was arrested for practicing medicine without a license, leading to a misdemeanor conviction.
In 1986 while promoting himself as a naturopathic doctor, Young was operating the Rosarita Beach Clinic in Tijuana, Mexico, offering "detoxification" for cancer and lupus using treatments whose efficacy was questioned in an investigative report by the Los Angeles Times. To test the veracity of Young's clinical diagnosis, a reporter submitted cat and chicken blood to a clinic employee, who failed to determine that the samples were non-human, and further diagnosed that the "patient" had an aggressive form of cancer and liver disease.
In 1989, Young started cultivating plants in Spokane, Washington, and built two distillation units. In 1993, he founded Young Living Essential Oils in Riverton, Utah. Young later moved the company to Lehi, Utah, and focused on employing methods of harvesting and extraction, which the company marketed without evidence as "customs that were practiced during the period of Christ." Young Living is reported to be one of the largest vendors of essential oils in the United States with over three million customers. It operates as a multi-level marketing company in which 94% of Young Living's two million active members made less than a dollar in 2016.
Besides selling essential oils to its members, Young Living operated a clinic in Springville, Utah, which dispensed essential oils and other alternative medicine treatments for numerous conditions, including cancer and depression. After settling a lawsuit with a former patient who claimed the clinic's vitamin C therapy had caused kidney failure, the clinic closed its Utah branch and re-opened in Ecuador.
The company's essential oil sales grew quickly in the 2000s. The company's largest competitor, doTerra, was started in 2008 by executives who had left or been fired from Young Living. Both Young Living and doTerra have been cited by the Food and Drug Administration for making misleading claims about the medical benefits of their products.
In 2014 while Young was chief executive officer (CEO) of Young Living, the U.S. Food and Drug Administration (FDA) warned him and his company about illegally marketing products that had not been FDA approved as possible treatments or cures for Ebola virus, and other diseases, including "Parkinson’s disease, autism, diabetes, hypertension, cancer, insomnia, heart disease, post-traumatic stress disorder, dementia, and multiple sclerosis, that are not amenable to self-diagnosis and treatment by individuals who are not medical practitioners." In 2015, he stepped down as CEO with his wife assuming the role.