Long game
Does it change a biological age clock?
A clock is a prediction, not an outcome. Moving one has never been shown to change what happens to a person, and that limitation belongs on the result.
903
people in trials
3
human studies
2
compounds, animal or cell only
0
trials found nothing
Measured in people
Ranked by how many people, which is a fact about the evidence and not a judgement about the compound. The one at the top is the most studied, which is not the same as the best. Counts are never added across compounds, because the same person can appear in more than one trial.
- 876 people1 human study
876 Swedish men aged 35 to 80 followed up to 14 years: serum GDF15 at entry predicted all-cause mortality with an adjusted odds ratio of 3.38 (95 percent CI 1.38 to 8.26), validated in 324 same-sex twins and independent of telomere length, IL-6 and CRP. An association in a cohort, not an intervention.
Aging Cell, 2010 · 876 people
- 27 people2 human studies
The result that makes danazol interesting. Phase 1 to 2 prospective study, 27 patients with inherited telomere diseases, danazol 800 mg a day orally for a planned 24 months, primary efficacy endpoint a 20 percent reduction in annual telomere attrition. Halted early because attrition was reduced in all 12 patients evaluable for the primary endpoint; 12 of 27 (44 percent) met it in intention to treat. 11 of 12 (92 percent) gained telomere length at 24 months against baseline, mean increase 386 base pairs. Haematological response in 19 of 24 evaluable at 3 months and 10 of 12 at 24 months. Grade 2 or lower elevated liver enzymes in 41 percent and muscle cramps in 33 percent.
New England Journal of Medicine, 2016 · 27 people
A Mayo Clinic report describing pancreatitis in the setting of danazol therapy for telomere biology disorders, published eight years after the original trial. An adverse effect identified in ongoing clinical use rather than in the trial.
Mayo Clinic Proceedings, 2024 · no headcount in the line
What people using it report
- Discussed in longevity circles almost entirely on the strength of the 2016 telomere result, usually without the enrolment numbers, the early stop or the disease context attached.
Measured in animals or cells, not yet in people
These are separated from the trials above rather than ranked against them, because they answer a different question. A result in a rat is a real result and a reason somebody ran the study; it is not a measurement of what happens in you. Where the human work is missing, the reason is usually money rather than failure, and that is set out at the bottom of this page.
- 1 preclinical study
Measured in animals or cells
The first replication of the direction of the telomere effect by a group unconnected to the originators: dose-dependent telomere lengthening in normal human epithelial and fibroblast cells through hTERT and telomerase, with alternative lengthening of telomeres seen mainly in cancer lines. A November 2025 correction notice (PMID 41240216) replaced Figures 1 to 3 without changing the conclusions.
What people using it report
- Sleep dominates the reports. SelfAssay's aggregated community corpus of 258 first-hand reports from 236 contributors lists improved sleep 95 times, far ahead of any other reported benefit, with longevity and telomere lengthening (23 each) cited as expectations rather than felt effects, and vivid dreams and steadier wake times also common.
- A large share of users report feeling nothing at all, and long-running longevity forum threads on Epitalon circle the same question for years without resolving it: whether anyone has produced a measurable result, and what a longer telomere would even feel like.
- The telomere and biological-age numbers people post are the weakest part of the discussion. One documented multi-month self-experiment used a saliva DNA methylation test rather than a telomere test at all, because the only telomere-length test the participant could find cost about 290 dollars and required a blood draw and a physician; other participants in the same thread disputed whether the epigenetic-age result was plausible. Consumer telomere and epigenetic-age tests carry error bars wide enough to contain the entire claimed effect, and almost none of these reports include a baseline measured on the same platform.
- 1 preclinical study
Measured in animals or cells
Mouse, physiologically ageing wild-type rather than progeroid. Long-term partial reprogramming regimens produced duration-dependent effects in kidney and skin, with reversion of epigenetic clock measures and reduced inflammation, senescence and stress-response gene expression. The authors make no lifespan extension claim for wild-type mice.
Nature Aging, 2022 · animal
What people using these actually report
Uncontrolled self-reports, gathered from clinic write-ups, regulatory complaint records and public forums, and reproduced here as written. They are the best guide on this page to what people actually do, what they expect, and what goes wrong, and they cannot show that anything works, because nobody was measured against a placebo and the people who saw no effect mostly stopped posting. Both halves of that are true at once. The negative reports are kept in for the same reason.
- Discussed in longevity circles almost entirely on the strength of the 2016 telomere result, usually without the enrolment numbers, the early stop or the disease context attached.
Sources: Longevity forums and patient communities in aplastic anaemia and telomere biology disorders. Uncontrolled self-report, and the patient communities are describing a different population from the people considering it for ageing.
- Sleep dominates the reports. SelfAssay's aggregated community corpus of 258 first-hand reports from 236 contributors lists improved sleep 95 times, far ahead of any other reported benefit, with longevity and telomere lengthening (23 each) cited as expectations rather than felt effects, and vivid dreams and steadier wake times also common.
- A large share of users report feeling nothing at all, and long-running longevity forum threads on Epitalon circle the same question for years without resolving it: whether anyone has produced a measurable result, and what a longer telomere would even feel like.
- The telomere and biological-age numbers people post are the weakest part of the discussion. One documented multi-month self-experiment used a saliva DNA methylation test rather than a telomere test at all, because the only telomere-length test the participant could find cost about 290 dollars and required a blood draw and a physician; other participants in the same thread disputed whether the epigenetic-age result was plausible. Consumer telomere and epigenetic-age tests carry error bars wide enough to contain the entire claimed effect, and almost none of these reports include a baseline measured on the same platform.
Sources: LongeCity 'Telomeres' forum threads on Epitalon and Epithalon; the Age Reversal Forum self-experimentation thread on Epitalon (AEDG); SelfAssay's aggregated community corpus for Epitalon (258 reports, 236 contributors); vendor price tracking at peppers.market (73 vendors, retrieved August 2026). Reddit's r/Peptides is the most cited venue for this compound but was not directly readable when this section was compiled, so nothing here is drawn from it.
- Longevity clinics market therapeutic plasma exchange under names including plasmapheresis, albumin exchange and blood cleansing, typically in courses of several sessions, and typically citing epigenetic clock readouts as the endpoint. Clock readouts are the outcome being sold, which is exactly the endpoint the two 2025 randomised trials disagree about.
Sources: The published trial reports themselves, which is where the adverse event and laboratory-change numbers above come from: the AMBAR primary results in Alzheimer's and Dementia 2020, the Aging Cell 2025 randomised trial and the Scientific Reports 2025 crossover trial. The description of how the procedure is marketed reflects the endpoints those clinics advertise, which are the epigenetic clock measures named in the trials. No clinic, forum post or individual patient account is quoted or relied on.
Why the trial record looks like this
A missing trial is usually a missing sponsor. Nobody runs a nine-figure programme on a molecule they cannot own, so the compounds with the thinnest human records are often the oldest and most freely available ones rather than the weakest. Taking Epitalon as the example, because it states the problem most clearly:
Epitalon's research record is shaped by where it came from. The peptide bioregulators were developed inside the Soviet military medical system in the 1970s, where preparations from thymus and pineal tissue were first used to restore immune function in personnel exposed to radiation and toxic agents. The clinical work that followed was published in Russian-language journals during and after the Cold War, in a literature Western reviewers largely did not read, index or attempt to reproduce. That is a specific, non-scientific reason for the replication gap, and it is separate from whether the compound works.
The economics point the same way. Epitalon is four amino acids long. Any peptide synthesis lab can make it, and price trackers currently list dozens of vendors selling it for roughly 1 to 26 US dollars per milligram. There is no exclusivity for anyone to defend, so no company has a commercial route to recover the cost of the blinded, placebo-controlled trial that would settle the question. A thin trial record here is partly an economic fact rather than a verdict on the molecule.
Neither of those explanations resolves the scientific problem, which is real. Decades of positive results from a single research lineage, published largely in journals close to that lineage, with no independent replication, is precisely the pattern produced by a genuine effect nobody else bothered to test and also precisely the pattern produced by measurement, selection and expectation artifacts inside one group. Both hypotheses predict the same record, which is why the record cannot settle the question in either direction. The one point of outside traction so far is in cells, not people: the 2025 Brunel result reproduced the direction of the 2003 telomere finding. Vladimir Khavinson, who led the group for four decades, died in January 2024, so any confirmation now has to come from outside it.
A compound appears here only when a citation on its own page states this outcome and reports a result for it; naming it is not enough. Human, animal and cell work are counted separately and never merged. Participant counts are read from the study lines and deliberately undercount. Nothing here is advice, and nothing here is a recommendation to take or to avoid anything.