GDF-11
September 26, 2023Promising
5/10
Purrptide digest
GDF-11 became famous as a 'young blood' factor — found at higher levels in young mice and linked to reversing age-related heart thickening when transferred to old mice. The initial excitement was followed by a wave of contradictory papers. Some labs replicated the heart benefits; others found GDF-11 actually increases with age and impairs muscle regeneration. This is one of the more genuinely contested entries on the list — the science is still actively fighting about what this peptide does and whether it's good or bad news.
What this means for you
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If you care about weight/health
Genuinely unsettled science. This is not a 'just try it' peptide — the research community itself disagrees about the direction of the effect.
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If you're a clinician
Contradictory findings across labs on whether GDF-11 helps or harms muscle regeneration make this one to flag as unresolved if patients ask.
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If you're a researcher
The replication crisis around GDF-11 is itself a worthwhile case study in how parabiosis findings can mislead before careful follow-up work.
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If you follow biotech
The 'young blood' narrative drove huge interest, but contested science makes this a riskier biotech bet than the headlines suggested.
LO
Loffredo et al.
Harvard Medical School
For the nerds
Growth Differentiation Factor 11 Is a Circulating Factor that Reverses Age-Related Cardiac Hypertrophy
Cell · DOI: 10.1016/j.cell.2013.04.015
Read full paper on PubMed →