A burst of fenoterol excretion during the recovery of a weight loss protocol.

Fenoterol is a sympathomimetic β2 receptor agonist primarily used as a bronchodilator. Due to its sympathomimetic actions, the World Anti-Doping Agency (WADA) has banned it. Multiple acute weight loss protocols (WLP) are used by Olympic athletes for sports that segregate athletes by weight; these generally involve caloric and water deprivation combined with heat exposure.

Dietary higenamine from Annonaceae family fruits as a possible source of unintentional doping.

Members of the genus Aconitum have been used for millennia, both as poisons and medicines, in Eastern culture. Higenamine has non-selective beta-agonist effects, activating both β and β adrenoreceptors, and is present in a variety of plants. The World Anti-Doping Agency has banned Higenamine both in competition and out of competition.