[2] In 1931, chemists M. Bridel and R. Lavielle isolated the glycosides stevioside and rebaudioside that give the leaves their sweet taste.

Beginning in the 1960s,[4] commercial cultivation had spread to Japan, Southeast Asia and the US, but also in mildly tropical climates in hilly areas of Nepal or India (Assam region).

Stevia rebaudiana has been grown on an experimental basis in Ontario, Canada, since 1987 to determine the feasibility of commercial cultivation.

[9] Duke University researchers developed a strategic plan to assist farmers and exporters in Paraguay to compete in the global market for stevia.

[6][13] Based on the JECFA (Joint Expert Committee on Food Additives) declaration, safe consumption of steviol glycosides for humans is determined to be 4 mg/kg body weight per day.

[citation needed] Stevia leaf and raw extracts are not treated as GRAS and their import into the US is not allowed for usage as sweeteners.