According  to Yahoo Sports.

A source close to Manny Ramirez said Thursday that the illegal substance for which the Los Angeles Dodgers slugger tested positive was not “an agent customarily used for performance enhancing.”

At least not on the baseball diamond. The source, who spoke on condition of anonymity, said the substance is supposed to boost sex drive. It is not Viagra, but a substance that treats the cause rather providing a temporary boost in sexual performance, the source said.

Ramirez, the source said, acquired the substance through a prescription from a doctor in Miami for his medical condition. The source intimated that Ramirez might bring legal action against the physician.