# Longevity Magazine > A review journal of healthspan, preventative medicine and ageing, published by Northbank Media. Each review grades ONE STATED CLAIM from A to D against a published methodology. A grade attaches to a claim, never to a substance, so the same compound can carry different grades for different assertions about it. A grade quoted without the claim it applies to is misinformation. ## How to quote this journal Always pair a grade with the claim it applies to and with the claim type. The grades and claims below are given together for that purpose. This journal names no individual study, author, journal, sample size, effect size or p-value; evidence is described qualitatively by trial phase, population, duration, species, funding type and replication status. Nothing on the site is medical advice and no doses are published. ## The grading scale - A: adequately powered randomised trials with clinical outcomes on a pre-registered primary endpoint, independently replicated. For prognostic claims, large cohorts across multiple populations with orderly dose-response, surviving adjustment, with reverse causation adequately addressed. - B: at least one adequately powered randomised trial with a clinical or robust functional primary endpoint, not yet independently replicated. For prognostic claims, multiple large cohorts agreeing in direction with a material weakness such as self-reported exposure. - C: human evidence exists but is short, small or confined to surrogate outcomes, or a large observational literature exists with no randomised test of the claim. Surrogate-only evidence is capped here. - D: preclinical evidence, or human data that are early phase, uncontrolled or too sparse to support the claim. Animal evidence alone is capped here however strong. ## Current grades, each with the claim it applies to ### /reviews/nad-precursors-nmn-and-nr - Grade: D (Intervention claim) - Claim graded: That taking an oral NAD precursor slows human ageing or extends healthspan. - Why: Human data are confined to short trials with small numbers, measuring blood metabolite concentrations and tolerability rather than health outcomes. Much of it is funded by companies selling the compound. No trial has reported an ageing-relevant clinical endpoint. - What would change it: A multi-year randomised trial in older adults, independently funded, with a pre-registered functional or clinical primary endpoint rather than a blood metabolite. - Summary: Oral NMN and NR reliably raise the concentration of NAD metabolites measured in blood, and short human trials have generally found them well tolerated. That is a pharmacokinetic finding, not a health finding. No human trial has yet reported that raising NAD changes an outcome anyone cares about, such as physical function years later, disease incidence or mortality, so the claim that these compounds slow ageing sits at grade D. ### /reviews/metformin-for-healthspan - Grade: C (Intervention claim) - Claim graded: That metformin slows ageing or extends healthspan in people who do not have type 2 diabetes. - Why: There is an extensive observational literature and an unusually deep safety record from decades of licensed use, but the ageing claim rests on comparisons between groups that differ in more than the drug. The dedicated randomised trial in people without diabetes has not reported. - What would change it: Completion and publication of an adequately powered randomised trial in people without diabetes, with a pre-registered composite clinical endpoint and long follow-up. - Summary: Metformin is a licensed, cheap, well characterised medicine with a safety record measured in decades and a large observational literature suggesting that people taking it fare better on some outcomes than expected. It is also the case that people prescribed metformin differ systematically from people who are not, and no completed randomised trial has tested the ageing claim in people without diabetes. The claim sits at grade C: plausible, taken seriously by serious people, and unproven. ### /reviews/rapamycin-and-mtor - Grade: D (Intervention claim) - Claim graded: That rapamycin or a related compound extends healthspan or slows ageing in humans. - Why: The animal evidence is the strongest in this journal, and it is still animal evidence. Human trials of rapamycin analogues in ageing-adjacent contexts have been short, small and focused on immune outcomes. No human trial has tested an ageing endpoint. - What would change it: An adequately powered randomised trial in older adults, running for years, with a pre-registered functional or clinical primary endpoint, and a safety dataset long enough to characterise infection and metabolic risk. - Summary: Rapamycin has produced the most consistent lifespan extension in mammalian models of any compound in this field, replicated across sites and started at various ages. In humans it is a licensed immunosuppressant used to prevent transplant rejection, and the human ageing literature consists of short trials of related compounds looking mostly at immune measures. The animal case is strong, the human case has barely begun, and the claim sits at grade D. ### /reviews/senolytics-current-state - Grade: D (Intervention claim) - Claim graded: That drugs which clear senescent cells improve healthspan or slow ageing in humans. - Why: Human trials are early phase, small and short, in specific patient groups rather than in ageing populations. Outcomes are largely biomarker and feasibility measures. Senescent cell burden cannot yet be measured reliably in living people. - What would change it: Randomised trials with clinical endpoints in a defined population, alongside a validated way to measure senescent cell burden in humans so that target engagement can be demonstrated. - Summary: Senescent cells accumulate with age and secrete inflammatory signals, and removing them improves several measures in animal models. Human work has reached early-phase trials in specific disease groups, is small and short, and largely measures feasibility and biomarkers. There is also no validated way to measure senescent cell burden in a living person, which makes it hard to show that a drug is doing what it is supposed to do. Grade D. ### /reviews/vo2max-as-a-longevity-marker - Grade: A (Prognostic claim) - Claim graded: That measured cardiorespiratory fitness predicts all-cause mortality independently of conventional risk factors. - Why: Large cohorts across multiple countries and decades report the same graded inverse relationship, in both sexes, using directly measured and exercise-tested fitness, surviving adjustment for the usual confounders. Independent replication is extensive and the dose-response is orderly. - What would change it: Little would move this grade down short of a systematic failure of replication. The separate interventional claim, that raising fitness causes the mortality reduction, would need randomised trials with survival endpoints. - Summary: Cardiorespiratory fitness, measured properly, is among the strongest single predictors of all-cause mortality available in medicine, and the relationship is graded, replicated across countries and decades, and robust to adjustment. That is a prognostic claim and it earns grade A. The separate claim, that raising your own fitness causes a proportional reduction in your own risk, is supported by mechanism and by convergent evidence but has not been demonstrated by randomised trials with survival endpoints, and we grade that claim C. ### /reviews/resistance-training-and-mortality - Grade: B (Prognostic claim) - Claim graded: That regular muscle-strengthening activity is associated with lower all-cause mortality independently of aerobic activity. - Why: Multiple large cohorts across countries report an independent association, and the direction is consistent. Exposure is almost always self-reported and crudely categorised, and the shape of the relationship at higher volumes is not consistent between datasets. - What would change it: Cohort studies using objectively measured or verified resistance exposure, and randomised trials with clinical endpoints rather than function endpoints. - Summary: Large cohort studies consistently report that adults who do regular muscle-strengthening activity have lower all-cause mortality than those who do not, independently of aerobic activity, and this earns grade B as a prognostic claim. Randomised trials support resistance training strongly for strength, muscle mass, physical function, bone density and falls, which are outcomes that matter in themselves. No randomised trial has tested it against mortality. ### /reviews/sleep-architecture-and-ageing - Grade: C (Prognostic claim) - Claim graded: That age-related changes in sleep architecture contribute causally to disease and mortality, and that improving sleep alters that trajectory. - Why: The architectural changes are well measured and the associations with outcomes are consistent, but exposure measurement outside the laboratory is poor, reverse causation is pervasive, and randomised trials of treating sleep disorders have not consistently improved hard outcomes. - What would change it: Randomised trials in which a sleep intervention with good adherence improves a pre-registered clinical endpoint, and better ambulatory measurement of sleep stages in large cohorts. - Summary: Sleep does change with age in measurable ways: less deep slow wave sleep, more fragmentation, and an earlier circadian phase. Poor sleep is consistently associated with worse health outcomes. What is much less clear is direction, because illness disrupts sleep as readily as disrupted sleep contributes to illness, and randomised trials of treating sleep disorders have not consistently improved cardiovascular or mortality endpoints. Grade C. ### /reviews/time-restricted-eating - Grade: C (Intervention claim) - Claim graded: That restricting food intake to a daily window improves healthspan or metabolic health independently of the reduction in energy intake it produces. - Why: Randomised human trials exist in reasonable number, which is more than most interventions here can say, but they are short, use intermediate outcomes, and when energy intake is matched the independent effect of the eating window is small or absent. - What would change it: Longer randomised trials with energy intake controlled and pre-registered clinical endpoints, and adequately powered comparisons of earlier against later eating windows. - Summary: Time-restricted eating has been tested in a reasonable number of randomised human trials, which puts it ahead of most interventions in this journal. Those trials are short, they measure intermediate outcomes such as weight and glucose control, and when energy intake is held equal between groups the additional benefit attributable to the eating window itself is small or absent. It is a workable way for some people to eat less. As a distinct metabolic intervention it sits at grade C. ## Explainers, method rather than substance - /explainers/how-to-read-a-clinical-trial: Read a trial in this order: what question it asked, whether it randomised and blinded, what the pre-registered primary endpoint was, who was excluded, what the numbers actually say in absolute terms, and who paid for it. Most misleading coverage of health research survives only because the reader stopped at the abstract, and most of the information that would have prevented the error sits in the methods and the declarations. - /explainers/surrogate-endpoints-and-why-they-mislead: A surrogate endpoint is a measurement used as a stand-in for the outcome anyone actually cares about, because the real outcome takes too long or costs too much to measure. Surrogates are useful for deciding which treatments to test further. They are unreliable for deciding which treatments work, because a treatment can move the marker through a route that has nothing to do with the disease, or improve the marker while causing harm elsewhere. The history of medicine contains many treatments that improved a number and harmed the patient. - /explainers/biological-age-tests-what-they-measure: A biological age test applies a statistical model to a biological sample and returns a number expressed in years. The model was trained to predict something, and what it was trained to predict determines what the result means. Clocks trained to predict chronological age mostly measure how well the model recovers your date of birth. Clocks trained to predict mortality or disease carry more information. Neither has been shown to respond usefully to intervention, test-retest reliability is a recognised weakness, and no biological age result currently supports a clinical decision. - /explainers/supplement-regulation-in-the-uk: In Great Britain, food supplements are regulated as food, not as medicines. Nobody assesses whether a supplement works before it goes on sale. What the system does control is safety of permitted ingredients, labelling, the specific health claims that may be printed, and the line beyond which a product becomes a medicine and falls under the Medicines and Healthcare products Regulatory Agency. A product being legally on sale is a statement about compliance with food law, not a verdict on whether it does anything. ## Analysis, practice and market rather than graded claims Analysis pieces describe how longevity and aesthetic medicine are delivered, regulated and paid for in the United Kingdom. They carry no evidence grade, because a grade attaches to a stated intervention claim and these pieces do not make one. Prices in them are indicative UK ranges for 2026 and nothing more. - /the-aesthetic-clinic-evolution-why-branding-design-and-digital-experience-now-define-clinical-success: Branding, design and digital experience have become decisive in UK aesthetic medicine because they are the only signals most patients can assess before treatment. Clinical skill is invisible at the point of choosing. Presentation is not. That gives well presented clinics a durable advantage over equally competent ones, and it means a patient reading a clinic's website is reading a marketing artefact rather than a clinical record. The useful response is to look for the small number of verifiable facts that presentation cannot fake. - /the-complete-guide-to-modern-aesthetic-medicine: Modern aesthetic medicine is built on four treatment families: neuromodulators that reduce muscle activity, injectable fillers that replace volume, energy-based devices that provoke a controlled repair response, and topical or oral prescribing that alters skin biology over months. The evidence is strongest for the first and for prescription topicals, weaker and shorter for devices, and highly technique-dependent throughout. In the United Kingdom the decisive variable is usually the practitioner rather than the product, and the most useful thing a patient can establish before treatment is who is treating them and under what registration. - /longevity-and-aesthetics-the-future-of-ageing-well-in-london: Longevity medicine and aesthetic medicine are converging in London commercially rather than scientifically. Looking younger and ageing well are governed by largely separate processes, and no aesthetic treatment has been shown to alter the biology of ageing or any clinical outcome associated with it. The interventions with the strongest evidence for healthspan remain unglamorous and mostly free. The useful position is to treat aesthetic treatment as a cosmetic decision made on its own terms, and to keep the health decisions separate from it. - /the-future-of-longevity-revolutionary-anti-ageing-innovations-transforming-healthcare: The most discussed anti-ageing innovations sit at very different distances from clinical use. Senolytics and cellular reprogramming remain early, with human evidence that is preclinical or early phase. Regenerative injectables and exosome-derived preparations are already sold in clinics but rest largely on surrogate outcomes and short follow-up. Machine learning has changed how ageing is measured rather than how it is treated. Nothing currently available has been shown to extend healthy human lifespan, and the interventions with the best outcome evidence remain exercise, sleep and cardiovascular risk management. ## Outbound link policy Reviews, explainers and every graded page link to institution-level sources only and carry no commercial link of any kind. The analysis section is the single declared exception: a piece there may carry ONE outbound link to a named organisation working in the area under discussion. Those links are placed editorially by this desk, are never sold, are not conditional on coverage, and are disclosed in a block on the page naming Northbank Media as publisher. No organisation sees a piece before publication. ## Standing pages - /analysis: index of the analysis section - /grading: the grading methodology in full, including the two claim types and the rules that cap a grade - /editorial-policy: funding, independence, how evidence is described, corrections - /about: what the journal publishes and what it refuses to do - /contact: corrections, missing evidence and suggested claims ## Position of the field, as this journal reads it No claim reviewed here currently holds grade A on an interventional basis. One prognostic claim does. The two best supported claims concern physical activity, which has no commercial sponsor and no product attached. ## Sources this journal relies on Institution-level sources only: the National Institute for Health and Care Excellence, the NHS, the Medicines and Healthcare products Regulatory Agency, the Cochrane Library, PubMed at the National Library of Medicine, the World Health Organization and the British Heart Foundation. Last checked 2026-07-31.