Disgraced Theranos founder, Elizabeth Holmes, looks set for prison after a court rejected her latest attempt to stay free.
The 39-year-old entrepreneur was also ordered to pay $452 million (almost £363 million) to victims of her crimes by a court in California on Tuesday.
She is jointly liable for the restitution penalty with her former lover and Theranos second-in-command, Ramesh "Sunny" Balwani, who is already in prison after being convicted on a broader range of offences in a separate trial.
Holmes is trying to overturn her conviction for fraud and was appealing to remain out of jail while she does.
But US district judge Edward Davila, who sentenced her to more than 11 years in jail in November, will now set a new date for Holmes to report to prison.
Holmes had previously been told she must start her sentence on 27 April, but her lawyers tried a last-minute delaying tactic.
At her trial, Holmes accused Balwani, 57, of abusing her emotionally and sexually.
Prosecutors called her crimes "among the most substantial white-collar offences Silicon Valley or any other district has seen".
At her appeal, her lawyers cited alleged mistakes and misconduct during her trial and said errors and abuses that biased the jury were so egregious she should be allowed to stay out of prison while the appeal goes through.
That request has now been thrown out by both Mr Davila and the Ninth Circuit Court of Appeals.
Holmes has two children - a one-year-old son, William, and a three-month-old daughter, Invicta - with her current partner, William 'Billy' Evans.
The failure of her latest appeal will see her separated from them and sent to prison.
Her astonishing rise and fall from history-making billionaire to the brink of jail has inspired documentaries, podcasts, and an award-winning TV drama - The Dropout - starring Amanda Seyfried as Holmes.