Scientists still have no convincing answer as to whether medicine can substantially extend human life, but enormous sums are being invested in research on the subject: in March 2026 alone, the U.S. government agency ARPA-H allocated $144 million to developing biomarkers of aging and testing drugs to slow it. According to the WHO, by 2050 the number of people over 60 worldwide will double to 2.1 billion, while the number over 80 will triple to 426 million. Alongside extending lifespan, this makes extending youth – that is, increasing the healthy and productive years of life – an increasingly urgent goal. So far, however, the most advanced anti-aging treatments are available only to the very wealthy – and they almost always prove to be quackery.