Date	Event	Description
4 December 2018	New search has been performed	Nineteen new studies were added in this update (Barekat 2016; Blomberg Jensen 2018; Boonyarangkul 2015; Busetto 2018; Cyrus 2015; Deng 2014; Ener 2016; Exposito 2016; Gamidov 2017; Gopinath 2013; Haghighian 2015; Haje 2015; Martinez 2015; Mehni 2014; Micic 2017; Pourmand 2014; Raigani 2014; Sharifzadeh 2016; Sofikitis 2016). There is one study placed in awaiting classification (Goswami 2015). All pentoxifylline studies were excluded. Two previously included studies were excluded for containing an ineligible study population.
4 December 2018	New citation required and conclusions have changed	Pentoxifylline was removed from the review due to the fact that it is a prescription drug and not an 'over‐the‐counter' supplement. Progressive sperm motility was added as a secondary outcome; this is an outcome with more clinical importance than total sperm motility.