Major companies including Spotify, Oracle and Comcast have appointed co-CEOs this year, drawing fresh attention to a long-scrutinized corporate strategy that aims to pair dual leaders with complementary expertise to take on the top job. But Emma Walmsley, chief executive officer of GSK, isn’t sold on the leadership model, which is based, in part, on the idea that the CEO role has grown too vast—even unsustainable—for one person to handle.
“I think there are few things more obnoxious in life than CEOs complaining about how hard their life is,” Emma Walmsley told Fortune senior editor Claire Zillman during Fortune’s Most Powerful Women Summit on Tuesday.
Walmsley has served as CEO at GSK, a British drugmaker, since April 2017 and will step down in at the end of the year. Under Walmsley, GSK spun off its consumer health care business Haleon, won regulatory approval for its pioneering RSV vaccine, and expanded its HIV treatment portfolio. Still, she has failed to win over investors.
The 56-year-old acknowledged that a CEO role is demanding—personally and professionally—and that those who assume the top job need to be prepared “from a resilience and stamina point of view.” She said she took 38 trips to the U.S. last year and is currently on a swing that will take her to seven cities on three continents, all within ten days.
But that’s part of the responsibility that comes with being the head of a company, Walmsley said, advising CEO hopefuls to give the position “everything you possibly have.”
“It’s not about being a superhero,” Walmsley said of the chief executive position. “I don’t know if it’s about sharing the job.”
Spotify is the most recent company to adopt the co-CEO model. In September, it appointed two leaders to replace Daniel Ek in 2026. Earlier this year, Comcast said that sitting CEO Brian Roberts will be joined by Michael Cavanagh, former president, as a co-CEO in January. And just a week before that, Oracle restructured to a co-CEO model as well.
The co-CEO structure is rare but research suggests it can work. Co-CEOs generated average annual shareholder returns of 9.5% while in charge, higher than the 6.9% single-CEO average, according to a Harvard Business Review study of 87 public companies with co-CEOs between 1996 and 2020. Some firms in the study experienced productivity increases of more than 12%. The average co-CEO tenure was about five years, in line with sole CEOs. CEO advisor Marc Feigen led the study and previously told Fortune the model’s success depends on three factors: CEOs working together with separate areas of expertise, upholding shared values and a clear method of conflict resolution.
Walmsley said the co-CEO model could work if a company can create the right “cocktail” and combination. But she said CEOs must “be prepared to stand up and absorb all of the pressure” and look beyond themselves. “It’s not about you; get your ego out the way,” she said. “It’s about the team, it’s about the company, and it’s about the people that you serve.”
