The WADA statement shows that injections of less than 50mL were allowed prior to January 2012. The January 2012 WADA changed "clarified and re-emphasized" that injections less than 50mL were allowed.
Link and Statement below:
"An article in The Sunday Times (London) on Sunday, 29 March 2015, suggested that the U.S. Anti-Doping Agency (USADA) Science Director gave inaccurate advice in December 2011 by stating that injections of up to 50 mL of a non-prohibited substance were permissible under the WADA Prohibited List.
We have now received the communications that took place between Alberto Salazar and the USADA Science Director during December 2011.
We can confirm that the advice given by the USADA Science Director was accurate and consistent with medical practice in place at the time.
The change to the List on 1 January 2012 clarified and re-emphasized the practice relating to infusions and injections to ensure that medical practice was clear in that injections / infusions less than 50ml, and not less than 6 hours apart were permitted. Infusions / injections above that amount or frequency are prohibited.
We'll update our article to reflect this news.