In June 2009, in her first year as a professional, Oliveira tested positive for oxilofrine, a stimulant, while racing with the Italian professional team SC Michela Fanini at the Giro del Trentino Donne. The adverse finding came from a supplement purchased in the United States that did not include oxilofrine on the ingredients label. In fact, several supplement companies were making products that contained oxilofrine without indicating the substance on the label. Oliveira later sued the supplement manufacturer. In December 2009 the ban was reduced through an appeal to CAS after the panel found that she had not intentionally ingested the banned substance and there was no way that she could have known that the supplement would have contained a banned substance. This would see her resume competition on 1 March 2011.
