Little is known about the pharmacological and metabolic effects of R-nicotine in humans," says a 2021 article in Tobacco Control on the rise of synthetic nicotine.3 In other words, synthetic product users could be unwitting research subjects. There are inexpensive tests for distinguishing between R- and S- forms of the chemical and ways of separating the R-isomer from the S -isomer. By comparison, telling the difference between synthetic S-nicotine and tobacco-derived S-nicotine can be quite costly.