For Johanna Mercier, Gilead Sciences’ chief commercial and corporate affairs officer, leadership starts with a clear accounting of what sustains performance across a global role. In a job that rarely conforms to fixed hours, she focuses on her energy: what drains it, what restores it, and how to p rotect enough of it to lead with steadiness in a business where the stakes are measured in patients’ lives. Mercier describes energy as a kind of running reserve, something she tracks with intention.  “I think about it like a piggy bank,” she told Fortune Next to Lead. Some meetings, tasks, and decisions draw heavily from it, particularly long discussions that go in circles, internal debates that take too long to resolve, and periods when reaching a decision is slowed by overly bureaucratic processes. Other parts of the job restore it: visiting teams around the world, hearing what they are building, sharing best practices, supporting local strategies, clearing obstacles, and staying close to patient stories, healthcare professionals, and the communities Gilead serves. What matters is how she responds when that reserve starts to run low. “It’s about taking a pause and taking a step back,” she says, “and being really strategic about how I spend my time there.” The habit reflects a broader discipline: In a role with constant demands across markets and time zones—and where the mission carries extra weight—Mercier protects her energy by staying close to the work that creates momentum and by limiting how much of herself she gives to conversations that do not. That framework becomes especially important in drug development, where most efforts fall by the wayside long before a medicine reaches the market. Mercier calls it “scientific heartbreak” because teams grow attached to a medicine’s potential and to what it might do for patients. She leads through those moments by placing each setback inside the longer arc of clinical discovery. Mercier points to Lenacapavir, Gilead’s HIV prevention drug, which took 17 years to reach its first approval and emerged only after scientists worked through roughly 3,000 candidate molecules. At Gilead, where more than 50 clinical programs are active across phases one through three, that kind of attrition is a constant feature of the work. Her job, then, is not to deny the sting of a canceled program but to help teams turn disappointment into learning and keep moving toward the next viable breakthrough, she says. And for Mercier, that is where the energy returns. Watch the full interview with Mercier here. Ruth [email protected] This story was originally featured on Fortune.com ...read more read less