Jeremy, 67, pleaded not guilty in June to allegations that he raped three women and sexually assaulted another in separate attacks going back to 2014.
The District Attorney's Office amended the complaint Monday against the defendant -- whose real name is Ronald Jeremy Hyatt -- to include a total of eight forcible rapes and lewd conduct with a 15-year-old girl, among other counts.
If convicted on all counts, the porn star could face up to 250 years in life in prison.
He has been jailed in lieu of $6.6 million bail, despite a defense request to lower the amount.
Prosecutors said the victims range in age from 15 to 54 and that the teen was assaulted at a party she attended in Santa Clarita. The most recent allegation was made by a 21-year-old woman who alleged that Jeremy sexually assaulted her on New Year's Day of this year outside a business in Hollywood.
Ron Jeremy rape case: Investigators asking other alleged sexual-assault victims to step forward
A half-dozen of the other alleged assaults happened inside a West Hollywood bar the defendant frequented and another took place in the bar's parking lot, according to prosecutors.
The defendant is accused of raping a 25-year-old woman at a home in West Hollywood in May 2014. He is also charged with raping a 33-year-old woman and sexually assaulting a 46-year-old woman on separate occasions at a West Hollywood bar in 2017 and raping a 30-year-old woman at the same bar last July, according to the Los Angeles County District Attorney's Office.
The amended charges include eight counts of forcible rape, six counts of sexual battery by restraint, five counts of forcible penetration by a foreign object, four counts of forcible oral copulation and one count each of sexual battery, sodomy, assault with intent to commit rape, penetration by a foreign object on an unconscious or sleeping victim and lewd conduct with a minor.
The Los Angeles County Sheriff's Department said the case stemmed from a two-year investigation.
Ron Jeremy charged in 3 rapes, 1 sexual assault dating back to 2014