Ms Sangha now faces nine charges, including conspiracy to distribute ketamine and distribution of ketamine resulting in death.
The American-British dual-national, who wore a Nirvana sweatshirt for her court appearance, pleaded not guilty to the charges on Thursday.
Her bail request was denied by US officials and she will remain in custody until her trial in October.
The indictment alleges that Ms Sangha’s distribution of ketamine on 24 October 2023 caused Perry’s death.
Ketamine is a dissociative anaesthetic that has some hallucinogenic effects, according to the US Drug Enforcement Administration (DEA). It can distort perception of sight and sound and makes the user feel disconnected and not in control.
It is used as an injectable anaesthetic for humans and animals because it makes patients feel detached from their pain and environment.
The substance is supposed to be administered only by a physician, investigators say, and patients who have taken the drug should be monitored by a professional because of its possible harmful effects.
Ms Sangha is alleged to have supplied ketamine from her “stash house” since at least 2019.
Her North Hollywood home was a “drug-selling emporium”, Martin Estrada, the US attorney for California’s Central District, told a news conference on Thursday.
More than 80 vials of ketamine were allegedly found there in a search, along with thousands of pills that included methamphetamine, cocaine and Xanax.
The home, called the “Sangha Stash House” in the indictment, was where she is alleged to have packaged and distributed drugs.
She “only deal[s] with high end and celebs,” the indictment quoted her co-accused Erik Fleming as saying of Ms Sangha.
At the same time, she lived a jetsetter life which she shared widely on social media.
Ms Sangha is said to have mixed with celebrities socially as well, with one of her friends telling the Daily Mail she attended the Golden Globes and the Oscars.
Shortly after Perry’s overdose she posted pictures depicting her extravagant lifestyle, including parties and a trip to Japan and Mexico.
And the day before arrests were announced, her social media activity suggests she went to a hairdresser and dyed her hair purple.
The Instagram account where these posts were shared was confirmed as belonging to her by a spokesman for the US Attorney’s Office Central District of California.
Prosecutors claim Ms Sangha came to supply ketamine to Perry after fellow defendant Dr Salvador Plasencia initially learned that the actor was interested in the drug. Dr Plasencia sourced it from Dr Mark Chavez, another defendant in the case who had previously operated a ketamine clinic.
They allege Dr Plasencia also taught Perry’s live-in assistant, co-accused Kenneth Iwamasa, how to inject Perry with ketamine.
Beginning in October 2023, Ms Sangha began supplying Mr Iwamasa with ketamine and prosecutors say she knew the ketamine she distributed could be deadly.
“These defendants cared more about profiting off of Mr Perry than caring for his well-being,” said Mr Estrada.
He also alleged that Ms Sangha was a “major source of supply for ketamine to others as well as Perry”.