Fidji Simo, the executive tasked with transforming OpenAI’s research breakthroughs into a sustainable, profitable business, is taking a medical leave of absence. As the CEO of Applications, Simo occupies a pivotal role in the company’s current evolution, managing the monetization of ChatGPT and the broader deployment of AGI—functions that sit at the center of OpenAI’s commercial viability.
In an internal memo sent to staffers on Friday, the company announced that Simo will step away for several weeks to treat a worsening neuroimmune condition. OpenAI President Greg Brockman will oversee product operations during her absence, ensuring that the company’s aggressive roadmap for application development remains on track.
The toll of a hidden disorder
Simo is seeking treatment for Postural Orthostatic Tachycardia Syndrome (POTS), a disorder of the autonomic nervous system that regulates heart rate, blood pressure, and respiration. For those with POTS, the simple act of standing can trigger orthostatic intolerance, where insufficient blood flow to the heart leads to dizziness, chest pains, and fainting.
Simo’s struggle with the condition has been a long-term battle. Diagnosed in 2019, she previously recounted the difficulty of securing an accurate diagnosis, noting that one physician initially dismissed her symptoms—which included constant fainting and weakness—as the result of being a “tired mom.”
The demands of her role at OpenAI have exacerbated the condition. In a memo viewed by CNBC, Simo revealed she had postponed medical tests and new therapies to avoid missing a single day of work since joining the company in May. She noted that the past month had been “particularly rough health-wise,” necessitating a period of stabilization and new medical interventions.
Managing the “Other CEO” role from afar
Simo’s leadership style has already been adapted to her health needs. Due to a relapse of POTS that makes her prone to fainting if standing for long periods, she has operated primarily from her home in Los Angeles. She has maintained a high-intensity presence via Slack and phone, often responding to employees within minutes from 8 a.m. Until midnight.
Her arrival at OpenAI followed a decade at Facebook, where she served as VP and Head of Facebook, and a tenure as CEO of Instacart from 2021 to 2025. This trajectory—from overseeing Facebook’s News Feed and advertising business to leading a major delivery platform—positioned her as the ideal candidate to architect OpenAI’s commercial layer.
Beyond her corporate roles, Simo has used her experience to fund research into the very condition she manages. She co-founded ChronicleBio, a biomedical research company focused on neuroimmune disorders, and serves as president of the nonprofit Complex Disorders Alliance (CODA).
Who is most susceptible to POTS?
While the disorder can affect anyone, It’s most common in women between the ages of 15 and 50. According to the National Institute of Health, POTS often triggers after a viral illness, major surgery, trauma, or pregnancy. Recent data suggests a link between long-term COVID-19 and the development of POTS, often accompanied by brain fog and cognitive issues.
Will this delay OpenAI’s profitability timeline?
While Simo is the primary architect of the company’s revenue-generating functions, the transition of product oversight to Greg Brockman suggests a move to maintain continuity. Since Simo’s leave is described as temporary—lasting “several weeks”—it is unlikely to cause a fundamental strategic shift, though it may slow the pace of specific application deployments in the short term.
How is the condition treated?
Treatment focuses on managing blood volume and flow. This typically involves lifestyle adjustments—such as increased salt intake and aggressive hydration—alongside medications that offer short-term relief, though long-term effectiveness varies by patient.
As the boundaries between high-performance corporate leadership and chronic health management continue to blur, how will the next generation of tech executives balance the “always-on” culture of AI with sustainable health?
