A drug lengthens the ends of chromosomes in a person
The caps on chromosome ends (telomeres) shorten with each cell division and with age, and some people inherit faults that shorten them fast, so their bone marrow and lungs fail young. In 2016 a National Institutes of Health group gave such people danazol, a synthetic hormone that had been on the market for decades, and measured their telomeres: in eleven of the twelve people who reached two years, the caps had grown longer, and most patients' blood counts improved. It is the first measured lengthening of telomeres in people by a drug. The drug is not approved for the purpose, a follow-up found the gain did not hold in everyone, and it was given for a rare disease, not for ageing.
What would count
A person given a treatment afterwards has measurably longer telomeres (the caps on chromosome ends) in their blood cells than before, in a peer-reviewed report with the measurement method stated. For the clinic rung: a regulator approves a treatment for lengthening telomeres, or for a telomere disease on the basis of lengthening them; off-label use does not count.
Who settles it: The peer-reviewed report; the regulator's approval record for the clinic rung.
Where it stands
First human. Reached 19 May 2016, on the record of doi.org. Next rung within 5 to 20 years.
When it reaches the clinic: the project's estimate
This is the one thing on this page that is a judgment rather than a record. The project's estimate of the year it reaches the clinic is 2036, no earlier than 2030 and no later than 2070; the model draws from that range every run, with the likely year the most probable draw. Set 16 October 2026, a first pass awaiting an outside review.
| Rung | No earlier than | Most likely | No later than | |
|---|---|---|---|---|
| In clinical use | 2030 | 2036 | 2070 | feeds the year at the top |
Why. The clinic rung needs a regulator's approval of a drug for a telomere disease, which is a rare disease with a short path if a sponsor takes it: the likely year assumes an approval of danazol or a related hormone for a telomere disease around 2034 after a confirmatory trial; the earliest assumes a filing on existing data within four years; the latest allows for no sponsor ever taking a generic drug through the process, in which case the rung is reached by some later treatment. An approval for ageing itself, rather than a telomere disease, is not what this leaf asks.
Changes to this record
None since it was written on 16 October 2026. Every change to the stage or the estimate lands here with its date, the old value, the new one and the reason, and a change to the estimate never happens because a number looked wrong: it needs a dated reason and a source.
The last readings
- 17 October 2026 Quiet
Nothing in the window 2026-10-10 to 2026-10-17. The nearest things seen were all older and all short of the test's clinic rung, which needs a regulator's approval: the National Institutes of Health low-dose danazol study in telomere disease (registry number NCT03312400) was last changed on 2026-05-29 and is listed as running to 2027-10-29 with no result posted, and a French multicentre trial of danazol in people carrying telomere-gene faults with lung scarring or marrow failure (the ANDROTELO study) was published in 2025 in ERJ Open Research, which the leaf does not name but which does not change the rung either way. The peer-reviewed Blood Advances version of the 2024 long-term follow-up that the leaf's verify list names could not be confirmed or ruled out, because no publisher page would open and the search did not surface it.source 1, source 2, source 3
What the story so far says about it
No promise, self-experiment or logged paper names this one yet.
Notes
Danazol is a prescription drug, and doctors at a few specialist centres give it to people with telomere diseases on the strength of this trial. That is off-label use, which the test excludes from the clinic rung on purpose, so that the rung means a regulator looked at the evidence. A telomerase gene therapy, the other route to the same result, has its own leaf at the animal rung.
Not yet verified
These facts in the record were written from memory or from a secondary source and have not yet been checked against the paper, the regulator's record or the registry. Nothing here is presented as settled until it is cleared, by checking it and either deleting the line or correcting the record.
- The 2024 long-term follow-up (conference abstract, 2024-12-08: telomere length stable in five of nine evaluable patients, still shortening in three, lengthening in one) now has a peer-reviewed version in Blood Advances (2026, volume 10, page 208); its figures have not been read.