In one case, the extract of a plant traditionally given to control thirst is to be marketed by a pharmaceutical company as an appetite suppressant.

BBC: Patent protection for traditional African remedies

Qsymia's other ingredient is phentermine, an appetite suppressant.

CNN: FDA approves new diet drug

Redux, its appetite-suppressant, was pulled from the pharmacy shelves last year after tests suggested that it might cause fatal heart defects.

ECONOMIST: Drug mergers