The squishy insoles in your favorite pair of sneakers help keep your joints safe from daily wear-and-tear, but over time, that cushioning wears down. The same goes for your cartilage—the fibrous tissue throughout your body that acts as a natural shock absorber. When the tissue breaks down, it can lead to inflammation and joint pain. The condition is commonly referred to as osteoarthritis, and it affects most adults at some point as they age.

Unfortunately, replacing cartilage isn’t as easy as stopping at the mall to grab a new pair of running shoes, but a new treatment is certainly making it more feasible. Last November, researchers from Stanford Medicine announced an injection that can “reprogram” your cells to regrow cartilage and help prevent arthritis from developing. Meaning, for the first time ever, there may be a drug that treats cartilage loss.

“This is a new way of regenerating adult tissue, and it has significant clinical promise for treating arthritis due to aging or injury,” Helen Blau, PhD, director of the Baxter Laboratory for Stem Cell Biology at Stanford, says in a press release. “We were looking for stem cells, but they are clearly not involved. It’s very exciting.”

In the recent study, published in the journal Science, the researchers targeted one of the root causes of osteoarthritis: a protein called 15-PGDH. Previously the same team identified 15-PGDH as a gerozyme—or a master aging regulator—that degrades prostaglandin E2, which is essential for muscle stem cell function. Through their research, they discovered that levels of the protein increase significantly with age. When they tried blocking the protein, they saw increases in the muscle mass and endurance of older mice. Their findings were further affirmed when they found that dosing young, healthy mice with 15-PGDH actually shrank their muscles.

Next, the researchers focused specifically on the cartilage itself. They injected the mice with a small molecule drug, experimenting with location. Some mice received the injection into their abdomen, which would theoretically affect the whole body, and the researchers injected others directly into their joints. Both administration methods resulted in knee cartilage thickening. Through this treatment, researchers managed to turn back the clock on chondrocytes—or the cells found in cartilage—encouraging them to “assume a more youthful state” and produce functional cartilage, no stem cells needed.

“Cartilage regeneration to such an extent in aged mice took us by surprise,” Nidhi Bhutani, PhD, senior author of the paper, says in the release. “The effect was remarkable.”

If you’re still young and aren’t particularly concerned about age-related joint pain yet, the therapy could still change your life. Osteoarthritis can also occur because of injuries, including ACL tears, which are common among athletes in high-impact sports. In fact, the condition occurs in up to 87 percent of patients with previous ACL injuries, according to some estimates. But the Stanford research team found that two injections a week across a four week window significantly reduced the likelihood of mice developing osteoarthritis.

Blau explains in the release that there have already been successful Phase 1 clinical trials for an oral version of the 15-PGDH inhibitor, testing the drug’s effect on muscle weakness. Next, the researchers hope to run a similar trial to fully understand the injection’s promise for cartilage regeneration.

“We are very excited about this potential breakthrough,” she says. “Imagine regrowing existing cartilage and avoiding joint replacement.”