The cleanest data point on the action side comes from a 2024 Dutch survey of 178 adults in Translational Medicine of Aging (PMC11573782), which measured stated willingness to adopt longevity interventions across a familiarity gradient: 81.5% willing to take supplements, 66.3% willing to exercise as a geroprotection regimen, 29.8% willing to do intermittent fasting, 26.4% willing to take metformin off-label, and only 9.55% willing to take rapamycin. Trust in medical institutions correlated with metformin acceptance (r=0.194, p=0.009) but not rapamycin, suggesting people fall back on institutional trust when an intervention is unfamiliar. Cross-referenced against CDC NHANES data brief 561, 60.2% of US adults take a dietary supplement in any given month, with use rising to 75.9% in adults over 60. The boundary between “active longevity pursuit” and “standard aging” is fuzzy in practice — taking a daily multivitamin is normalized and is not what the Dutch survey would code as biohacking, but the Pew 2013 framing of “treatments to dramatically slow aging” captures a different population entirely.
Kraus et al.’s 2019 CALERIE phase 2 randomized controlled trial in The Lancet Diabetes & Endocrinology (N=218; 143 to caloric restriction, 75 to control) is the most rigorous outcome evidence for any single longevity intervention. After 2 years, the restriction group achieved a mean 11.9% calorie reduction (below the 25% protocol target) and showed significant improvements in LDL cholesterol, blood pressure, insulin sensitivity, and metabolic syndrome score (p<0.001 to p=0.012). The biomarker case for one specific active intervention is solid. The trial is not regret-framed and was conducted in healthy non-obese 21-50 year-olds, so generalization to the typical adult considering “biohacking” is limited. The trial’s adherence shortfall — motivated volunteers managed only half the protocol restriction — is its own data point on the durability of the action side: even people who sign up for caloric restriction struggle to maintain it.
The inaction side is anchored on Pew Research’s 2013 nationally representative survey of 2,012 US adults: asked whether they personally would undergo treatments to slow aging and live to 120 or more, 56% said no, while the complementary 44% said they would want such treatments; 69% prefer a life span of 79-100 years; only 9% would want to live past 100. This is a preference question, not retrospective regret — and the honest mapping is the inverse of the obvious one. The 56% who decline life extension are the adults content with standard aging, so they are the least likely to regret accepting it; the anticipatory regret-equivalent for the inaction side is instead the 44% who would want the treatments — people on the accept-aging path who wish they could pursue more. We use that 44% as the inaction-side proxy. (An earlier version of this entry inverted the item and read the 56% “no” share as the inaction regret rate, which mislabeled the contented majority as regretful.) Adults answering at age 45 may feel differently at 75. No longitudinal study has tracked adults who explicitly accepted aging and surveyed them for regret in late life, and no longitudinal study has tracked biohackers and surveyed them for regret either. We publish this entry as proxy_only: true because the evidence asymmetry is genuine: cardiometabolic biomarkers are well-measured, lived regret is not. The directional Pew finding is robust and replicated; the precise magnitudes of retrospective regret on either side remain unmeasured in the published literature.