This image contains two bar graphs. The top graph compares the impacts of placebo, MDMA and its metabolite MDA, and the banned diet drug fenfluramine and its metabolite norfenfluramine in activating 5-HT2B receptor sites on heart valve cells. The bottom graph shows the relative levels of valve cell proliferation in response to each. . The data for each category follows:

5-HT2B receptor activation (percent of maximal response):

valve cell proliferation (multiples of placebo-associated level):