Meldonium was added to the World Anti-Doping Agency's (WADA) list of banned substances on Jan. 1.
However, on April 13 WADA said it was unable to establish how quickly meldonium cleared the human body. Hence, WADA deemed that the "the presence of less than one microgram of meldonium" in samples provided by athletes before March 1 was acceptable.
This allowed Markin, 25, a member of Russia's national team and the Dynamo Moscow club, to be cleared to compete in the Aug. 5-21 Rio de Janeiro Games.
"Just 15 minutes ago I got a message from the international federation that everything has been lifted," Markin said on Thursday in an interview with the R-Sport news agency.
In January Markin helped Russia qualify for the Olympics after winning a tournament in Berlin.
Last week a number of Russian sportsmen had their bans lifted, including five-times world champion speed skater Pavel Kulizhnikov, Olympic short-track speed skating gold medallist Semion Elistratov and 2015 European short-track champion Ekaterina Konstantinova.
(Reporting by Dmitriy Rogovitskiy; Editing by Mark Heinrich)
