Four metro Atlanta men were sentenced to federal prison for a steroid trafficking operation that used raw materials from China to produce and sell the drugs online.

Brandon Keith Franklin, Jay Michael Reger, Andrew Chrismer and Austin Britt Shirley were all sentenced for participating in the steroid business, which Franklin and Reger started in 2013 under the name Performance Formulations, acting U.S. Attorney John Horn said in a news release Wednesday.

According to the Department of Justice, the two business partners would import raw materials from China, which they used to produce anabolic steroids to later sell online.

They later hired Shirley and Chrismer to help fill orders, authorities said. Shirley and Chrismer were arrested in May 2014 after United States Postal Inspection Service and Drug Enforcement Administration officials seized tens of thousands of units of steroids from the operation, the U.S. Attorney’s Office said.

Franklin and Reger were later arrested and found guilty of drug trafficking charges. Franklin, 41, of Canton, was sentenced to two years, six months in prison. Reger, 30, of Woodstock, received a two-year sentence. Both of their sentences will be followed by three years of supervised release.

Chrismer, 25, of Atlanta, received a one-year sentence to be followed by two years of supervised release. Shirley, 25, of Acworth, was sentenced to two years of probation.

All four defendants pleaded guilty.

“The use of illegal anabolic steroids is far from a harmless pursuit. They pose significant health risks,” Horn said. “Thankfully, USPIS and DEA agents put these distributors, who sent their illicit product across the country, out of business.”