Like many men his age, William Stern was tired. At 45, the husband, father of three, and founder of Cardiff, a small-business lender, said he felt grateful but “run down” by his very full life.
Meanwhile, on social media, he’d started seeing posts from influencers extolling a panacea for this sort of midlife malaise—injectable peptides. Stern texted a doctor friend and got one prescribed: tesamorelin, a weekly self-administered injection that prompts the release of growth hormone.