Growth differentiation factor 11 is a circulating factor that reverses age-related cardiac hypertrophy

Researchers studied young and old mice. They joined pairs so their blood circulated together, a method called parabiosis, and also gave some old mice a laboratory-made version of GDF11, a body signal carried in the blood. The old mice exposed to young blood or GDF11 developed smaller, healthier-looking hearts and better heart function. This was an animal study, not a human trial.

What this means for you: This does not show that young blood or GDF11 supplements can reverse heart aging in people. Do not buy products based on this study; human safety and benefits remain unproven.