Key takeaways
- No treatment has been shown to reverse human aging. The best human trials so far show small effects on aging “markers” or small, early-stage safety results.
- In a 2-year randomized trial of 220 adults, cutting calories by 25% slowed one measure of the pace of aging slightly. Other measures did not change, and the authors call the effects “small.”
- Drugs that clear “senescent” (worn-out) cells have only been tested in tiny, open-label pilot studies in people who are already ill, with no control group.
- The National Institute on Aging (NIA) says exercise, healthy eating, enough sleep and regular health care are the proven ways to support healthy aging, and says to be skeptical of anti-aging products.
This article is general health information, not medical advice. Talk to your doctor before changing your diet, supplements or medicines.
What “reversing aging” would have to mean
Scientists test anti-aging ideas in two ways. One is to measure “biological age,” often with chemical tags on DNA called methylation patterns. The other is to see if a treatment delays diseases or keeps people healthier for longer. A treatment that improves a blood test is not the same as one that makes people live longer or healthier. Keep that in mind as you read the studies below.
Calorie restriction: the biggest randomized trial
The CALERIE trial, supported by the US National Institutes of Health, randomly assigned 220 adults without obesity to either a 25% calorie-restricted diet or their usual diet for two years. A 2023 analysis in Nature Aging looked at DNA methylation measures from the participants’ blood. The authors reported:
- The diet slowed the pace of aging as measured by one algorithm called DunedinPACE.
- It did not lead to significant changes in biological age estimates measured by other DNA methylation clocks, including PhenoAge and GrimAge.
- “Treatment effect sizes were small.” The authors add that “modest slowing of the pace of aging can have profound effects on population health,” and that a conclusive test would need a longer study.
It was a post hoc analysis, which means the question was asked after the trial finished, not planned in advance. And the study measured a marker, not how long people lived.
Senolytics: “clearing out old cells”
Senescent cells are cells that have stopped dividing and release inflammatory signals. They build up with age. Drugs called senolytics aim to clear them. The most studied combination is dasatinib plus quercetin. The human evidence is still very early:
- Lung fibrosis (2019): An open-label pilot of 14 people with idiopathic pulmonary fibrosis, a serious lung disease, tested the combination for three weeks. The authors reported the treatment was feasible and that physical function measures improved, with one serious adverse event and mild-to-moderate side effects such as respiratory symptoms, skin irritation or bruising and stomach discomfort. It had no control group.
- Diabetic kidney disease (2019): In an open-label pilot of 9 people, three days of the drugs reduced senescent cell levels in fat tissue within 11 days, according to the authors. They described it as the first peer-reviewed human study to show this.
- Early Alzheimer’s disease (2023): An open-label phase 1 trial with 5 people completed 12 weeks. The treatment was well tolerated, and the authors reported the drug dasatinib did reach the cerebrospinal fluid. Cognitive and brain-imaging results did not change significantly.
These are tiny studies in sick people, with no placebo group, designed to test safety and feasibility. They are not evidence that senolytics slow aging in healthy people. Dasatinib is a prescription drug, and nothing here is a suggestion to take it.
Metformin and the TAME trial
Metformin is a diabetes drug that extends life in some animal studies. A trial called TAME was designed to test whether it delays age-related diseases in about 3,000 people aged 65 to 79, and its designers have said they hoped it would lead to an FDA indication for targeting aging. The abstract we read is from 2017 and describes the plan; we did not find results. So any claim that metformin “slows aging in people” is, for now, unproven.
What the NIA says works
The NIA says many factors influence healthy aging. Some, like genetics, are outside our control. Others are within reach: “exercise, a healthy diet, going to the doctor regularly, and taking care of our mental health.” It lists staying active, healthy food choices, enough sleep, limiting alcohol and proactively managing health care. It notes a study of adults 40 and older in which taking 8,000 steps or more a day, compared with 4,000, was associated with a 51% lower risk of death from all causes. That is an association, not proof that steps caused the difference.
On products, the NIA’s skin-care page says: “Be skeptical about products that claim to be antiaging or able to reduce wrinkles.” It explains that many are considered cosmetics, not drugs, so they are not required to be tested in humans or approved by the FDA.
For related reading, see our guides to healthy habits and how the body replaces its cells.
How to spot hype
- “Reverses aging by X years.” Ask what was measured, in how many people, for how long, and whether there was a control group.
- A blood test instead of an outcome. Changes in a biological age test are not the same as living longer or avoiding disease.
- Animal results sold as human results. Mouse studies often don’t carry over to people.
- Supplements and clinics selling “age-reversal.” The NIA advises skepticism about anti-aging products.
Frequently asked questions
Can aging be reversed? Not in any way proven. Human trials so far show small effects on markers or early safety data.
Does eating less slow aging? In the CALERIE trial, 25% calorie restriction slowed one measure of pace of aging slightly. Other measures didn’t change.
Do senolytic drugs work? They have only been tested in small, open-label pilots in people with specific diseases. They are not approved to treat aging.
What does the NIA recommend? Regular exercise, healthy eating, enough sleep, limiting alcohol and regular health care.
Information checked on: November 13, 2026. Research changes quickly, so check current sources.
Sources
- Effect of long-term caloric restriction on DNA methylation measures of biological aging in healthy adults from the CALERIE trial. Nature Aging, 2023
- Senolytics in idiopathic pulmonary fibrosis: results from a first-in-human, open-label, pilot study. EBioMedicine, 2019
- Senolytics decrease senescent cells in humans: preliminary report from a clinical trial of dasatinib plus quercetin in individuals with diabetic kidney disease. EBioMedicine, 2019
- Senolytic therapy in mild Alzheimer’s disease: a phase 1 feasibility trial. Nature Medicine, 2023
- Targeting Aging with Metformin (TAME). Innovation in Aging, 2017 (abstract)
- National Institute on Aging, What Do We Know About Healthy Aging?
- National Institute on Aging, Skin Care and Aging
Health note: this article is for general information and is not medical advice. Speak to a qualified health professional about your own situation.
