The 44-year-old activist and actress surrendered to police in Loudoun County, Virginia on Monday.
She has pleaded not guilty and was released on $5,000 bond.
McGowan said the cocaine wasn't hers and suggested in court papers that the drugs were planted on her on behalf of former movie producer Harvey Weinstein, according to The Associated Press.
McGowan was among the first to accuse Weinstein of sexual assault and has been a vocal advocate of the #metoo movement.
Weinstein attorney Ben Brafman called the allegation "ludicrous" and said that police have "categorically rejected" the claim, TMZ reports.
McGowan's attorney, Jose Baez, told People Magazine: "Rose steadfastly maintains her innocence. These charges would have never been brought if it weren't for her activism as a voice for women everywhere."
“I assure you,” he continued, “this selective prosecution will be met with a strong defense.”
If found guilty, McGowan could face up to a year behind bars.