MLB issued a hard warning to its players this week: Stay away from gas station sex pills.

According to multiple reports, Major League Baseball sent a memo on Monday warning about the “very real risk” of over-the-counter sexual enhancement pills, after at least two players have blamed them for positive PED tests so far this year.

The memo, which was obtained by ESPN, says the pills in question are “often contaminated with prohibited and unsafe ingredients” including anabolic steroids. It reminded players that anyone who tests positive for a banned substance is subject to discipline by the league — regardless of how it got into their system.

According to ESPN sources, players use these supplements so often that the league felt compelled to send the memo and warn players of the risks.

“Sexual or male enhancement products present a very real risk for drug-tested players,” the memo said, “and the high likelihood for contamination or unidentified ingredients in these products underscores the importance of consuming only those products that are NSF Certified for Sport.”

The memo also suggested that any players who “suffer from erectile dysfunction or other legitimate issues related to sexual performance … speak to a licensed physician about the various prescription medications (e.g., Viagra, Cialis, Levitra) available to treat those conditions.”

The memo did not reveal which two players blamed their positive tests on the pills.