In 2003, ephedrine -- also known as ma huang -- became the first herbal stimulant ever banned by the FDA. It was a popular component of over-the-counter weight loss drugs. Ephedrine had some benefits, but it could cause far more harm, especially in high doses: insomnia (difficulty falling and staying asleep), high blood pressure, glaucoma, and urinary retention. This herbal supplement has also been associated with numerous cases of stroke.
The first media reports of Darkes' supposed cure, along with a similar description of the "rare" gene that partially explained it, began surfacing in February 2017. At the time, Darkes made it clear that his doctors in Northampton were still reviewing the test results, and that they would report on their findings soon. A story published in March 2017 in the Northampton Chronicle and Echo reported that Darkes' test results "are expected to be published next week."
^ Emadian A, Andrews RC, England CY, Wallace V, Thompson JL (November 2015). "The effect of macronutrients on glycaemic control: a systematic review of dietary randomised controlled trials in overweight and obese adults with type 2 diabetes in which there was no difference in weight loss between treatment groups". The British Journal of Nutrition. 114 (10): 1656–66. doi:10.1017/S0007114515003475. PMC 4657029. PMID 26411958.