TL;DR
For the first time, a cream aimed at the biology of aging, not just the look of it, has made human skin measure younger. In a small early trial, four weeks of a drug called RLS-1496 lowered the skin's biological age, as read from chemical marks on its DNA, by an average of 2.1 years, and it shrank sun-damage precancers by about half. Its maker projects a prescription product within three to four years. If it holds up, aging skin could become something doctors treat at the cellular level. The big caveat: the trial had no comparison group, and a younger reading on a lab test is not yet proof that skin is aging more slowly. For now, the only skin-aging treatment proven in a randomized trial is still daily sunscreen.
Below the line, for paid subscribers: The full story: where it stands, how we got here and what's dated next; our Odds board on 5 milestones, starting with "Rubedo starts its Phase 2b trial of RLS-1496 in sun-damage precancers by 2027"; our labeled speculation on what it adds up to; and every source.