Shkreli was sentenced to the seven-year term after a 2017 conviction for lying to investors about the performance of two hedge funds he ran, skimming money for himself from those funds, and defrauding investors in a drug company, Retrophin, by hiding his ownership of some of its stock. He was also ordered to forfeit $7.3 million.
Shkreli was originally due to be released from prison in September 2023.
Dubbed "Pharma Bro", Shkreli gained fame and notoriety after buying rights to Daraprim, a drug used to treat an infection that occurs in some Aids, malaria and cancer patients and raising its price from $13.50 to $750 per pill.
Shkreli defended the decision as capitalism at work, saying insurance and other programmes ensured that people who need Daraprim would ultimately get it.
During the campaign for the presidency in 2016, Democrat Hillary Clinton called it price-gouging and future President Donald Trump, a Republican, called Shkreli "a spoiled brat".
Shkreli resigned as chief executive of Turing Pharmaceuticals — later Vyera — in 2015, a day after he was arrested on securities fraud charges.
Earlier this year, he was ordered by US District Judge Denise Cote to return $64.6 million in profits he and his former company gained by raising the price of the drug. She also barred him from the pharmaceutical industry for life.
He also once regularly attacked critics on social media and once offered a bounty to anyone who could give him one of Hillary Clinton's hairs. He also was known for owning a rare, one-of-a-kind album by the Wu-Tang Clan which was sold to satisfy some of his court debts.
