UFC lightweight Mairbek Taisumov has received a six-month suspension from USADA after a positive drug test dating back to Sept. 15, 2018.

According to USADA officials, Taisumov tested positive for Stanolozol metabolites — a known anabolic steroid — as a result of a drug test administered at the UFC Fight Night event in Russia last September.

In the aftermath of the positive test, Taisumov was able to provide USADA with samples of the supplements he had been taking, which eventually led to the discover that he had used one that was contaminated with the banned substance.

“Following notification of his positive test, Taisumov provided USADA with information about dietary supplement products he was using before and at the time of the relevant sample collection,” USADA officials said in a statement. “USADA obtained open packages of the dietary supplements and collaborated with the Russian Anti-Doping Agency (RUSADA) to source unopened packages from Russia.

“Although no prohibited substances were listed on the supplement labels, product analysis conducted on both the open and independently sourced, unopened packages of the products by the WADA-accredited laboratory in Salt Lake City, Utah, indicated that they all contained stanozolol.”

As a result of the tainted supplement, Taisumov was offered a reduced six-month sentence for the violation of the UFC’s anti-doping policy.

The suspension started on Oct. 8, 2018, the date Taisumov’s provision suspension started, which means the sanction already ended on April 8 and he is eligible to compete again at any time.

Taisumov is currently riding a six fight win streak in the UFC.