Is GDF11 legal in the United Kingdom?

The young blood factor. Two famous 2013 and 2014 papers said it declines with age and rejuvenates. The human assay built to measure it properly found it does not decline, and that higher levels track with frailty.

GDF11 is the compound behind the young blood story. In 2013 a Cell paper identified it as a circulating factor that falls with age and whose restoration reversed age-related cardiac enlargement in mice.

Mechanism: Signals through activin type II receptors and SMAD2/3, the same axis as myostatin, and is more potent than myostatin at inducing SMAD2 phosphorylation in myocardium. That receptor sharing plus the near-identical mature domain is not a curiosity: it is the direct cause of the measurement dispute, because reagents and assays struggle to tell the two apart.

Regulatory history: Not an approved drug. No human trial of GDF11 administration has ever been run.

Licenses medicines for the UK market. A compound without a marketing authorisation is an unlicensed medicine, which can only lawfully be supplied for human use through a prescriber under the specials scheme, not sold as a research product.

The classification above is the The Longevity Archive reading of Medicines and Healthcare products Regulatory Agency listings for GDF11 at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.