Ramirez was suspended without pay for 50 games Thursday for testing positive for a performance-enhancing substance, Major League Baseball confirmed.
Ramirez issued a written statement through the Major League Players Association in which he apologized to the Dodgers and their fans and took responsibility for what he called a "mistake."
"Recently I saw a physician for a personal health issue," the statement said. "He gave me a medication, not a steroid, which he thought was OK to give me. Unfortunately, the medication was banned under our drug policy. Under the policy that mistake is now my responsibility."
Ramirez said he had been advised not to comment further other than to point out he had passed 15 drug tests over the past five seasons.
The Players Association said Ramirez would not contest the suspension.
The suspension, which is in line with baseball's strict sanctions for a first-time offense, went into effect immediately and will bench Ramirez until at least July 3, depending on possible rainouts.
Ramirez will lose $7.7 million in pay and cost the Dodgers both a major source of offense and a fan favorite. Ramirez is batting .348 with six home runs and 20 RBI this season.
The Los Angeles Times said minor-league outfielder Xavier Paul had been called up to fill Ramirez's spot on the roster, and Juan Pierre was expected to take over Ramirez's left field position.