'Young blood' anti-ageing mechanism called into question

Researchers studied GDF11, a blood protein thought to explain why young blood might restore ageing muscles. They measured the protein in young and old mice and gave extra GDF11 to some older mice. GDF11 did not decrease with age in these tests. Giving older mice more of it did not improve muscle repair and may have slowed it. The study involved mice, not people.

What this means for you: This does not support buying or seeking young-blood treatments for ageing. It challenges one proposed explanation, but it does not prove that all effects of young blood are false or harmful in humans.