TL;DR
Once a person's growth plates close, no pill or shot can make them taller. The only option is surgery that breaks a leg bone and stretches it, usually 2 to 3 inches per operation, with a year or more of recovery. That hasn't changed. What has changed is the parts bin. In 2026, scientists mapped living human growth plates and found dormant, stem-like cells waiting inside them. Drugs that turn up the growth plate's own "grow" signal are now approved or in front of the FDA for children. The first therapy that turns old cells young has been tried in people. And a Stanford team regrew real joint cartilage in old mice by making worn-out cells act young again. For the first time, every part of an adult-height machine exists somewhere in a lab or a pharmacy, though no one has yet reopened a closed growth plate in any animal. Our odds that adults add height with a treatment after their growth plates close: 60%, likely by 2042. To read the full breakdown of those odds and the timeline of breakthroughs that could lead to adult height gains, subscribe.
Below the line, for paid subscribers: all five parts with their odds, our step-by-step speculation on how they snap together, the odds for the whole machine and its bottleneck, what would change those odds, and who's most likely to build it.