Ranked No. 110 on the Forbes 400 in 2014, Holmes topped the list of America's Self-Made Women in 2015 with a net worth of $4.7 billion.
Holmes assembled what can be described as an all-star board of experienced and accomplished people in the corporate world: George Schultz, Bill Perry, Henry Kissinger, Sam Nunn, and Bill Frist, among others.
According to CBS News, Holmes spends every waking hour in her office and doesn't even own a TV at home.
In March 2015, Holmes became the youngest person ever honored as a lifetime member by the Horatio Alger Association of Distinguished Americans.
Holmes is notoriously secretive, and while she's been criticized by industry peers as such, insists she must protect her technology from the prying eyes of competitors.
Holmes went to Stanford for chemical engineering, and during her time there, filed her first patent (for an advanced drug-delivery patch). She then dropped out of college just before her sophomore year.
Her company name, Theranos, is a combination of the words therapy and diagnose.
Holmes was exceedingly private in the first 11 years of building her company. She's made a huge splash since appearing on the cover of Fortune magazine last summer.
Holmes has set her sights on more than simply dominating the blood-testing market; she wants to create a whole new market called "consumer health technology" that will see consumers more engaged in their health care.
She abstains from caffeine, limits the amount of time she sleeps, and works seven days a week.
While still in high school, Holmes completed three college Mandarin courses and sold C compilers to Chinese universities.
Holmes met Sunny Balwani, who would later become her company's COO, in Beijing the summer after her senior year of high school, during the time he was getting his MBA from Berkeley.
Holmes is often compared to visionary Steve Jobs and told Mercury News she launched her company after "thinking about what is the greatest change I could make in the world.".
Since launching in 2003, Theranos has developed blood tests to help detect dozens of medical conditions, including high cholesterol and cancer, using just a drop or two of blood drawn from a pinprick in your finger.
Holmes wears a daily "uniform" of a black suit with a black cotton turtleneck.
She once traveled to Singapore to spend a summer working in the Genome Institute labs on groundbreaking SARS research.
As of 2014, Holmes had 84 patents to her name (18 U.S. and 66 non-U.S.).
Part of Holmes's inspiration came from her aversion to needles; her mother and grandmother even fainted at the sight of needles.
According to The New Yorker, Holmes "can quote Jane Austen by heart, [but] no longer devotes time to novels or friends, doesn't date, doesn't own a television, and hasn't taken a vacation in 10 years ... She is a vegan, and several times a day she drinks a pulverized concoction of cucumber, parsley, kale, spinach, romaine lettuce, and celery.".
At just 9 years of age, Holmes wrote in a letter to her father, "What I really want out of life is to discover something new, something that mankind didn't know was possible to do.".
[October 2015] The Wall Street Journal published an investigation of Theranos by John Carreyrou alleging that only 15 of the 240 tests Theranos offers are conducted on the company's signature Edison machines, and that its lab test results were sometimes inaccurate.
She is known for her deep, husky speaking voice, though several journalists and past colleagues claim it is an affectation, and her real speaking voice is much higher. A 2005 appearance on NPR has Holmes speaking in a much higher voice.