NDGA dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
In male mice, it made them live longer at three different doses, and bigger doses did more. It never worked in females. It also harms the liver, which is why the plant it comes from was pulled from the supplement market.
Evidence grade for NDGA: Animal or lab only. The rule: only animal or lab studies on this page. No study in people yet. The sum on this page: 2 animal studies, no human study. A grade counts how much has been done to people, not whether it works.
- People given it
- 0
- Human studies
- 0
- Found nothing
- 0
Dose
No human dose established
No published study on this page has given this compound to people and reported a result.
2 animal studies, no human study
4 effects reported, 4 unwanted, by people using it, not a trial
Goal pages: Ageing and longevity, Hormones and growth hormone
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
This is a plant compound from the creosote bush. In male mice it made them live longer at three different doses. It also harms the liver. The herb made from the same plant was pulled from shop shelves for that reason.
What people take it for
- Living longer, because the mouse result held up at three doses.
- Mopping up damage inside cells.
What studies in people showed
Nobody has tested this in people for ageing. What we do have in people is a liver warning. Chaparral, the herb from the same plant, has been linked to cases of serious liver damage. In mice, male mice lived longer at the first dose, at one three times lower and at one three times higher. Bigger doses did more. Very few compounds repeat like that. But the longest lived mice did not live any longer. That usually means fewer died early, not that ageing slowed. Female mice got nothing.
What people report
Reports, not study results
The good
- We have not collected user reports on this one yet.
The bad
- Serious liver damage has been reported in people using the herb from this plant.
- The harm comes from what the molecule breaks down into. A purer product does not fix that.
- It did nothing for female mice.
- Only the typical lifespan went up in males. The longest lived mice did not gain.
Where these come from: The liver reports are from the human record of the herb, named on this page. The lifespan numbers are from the mouse studies here. No user reports exist.
My bottom line
A liver risk in people and a mouse win in males. That trade is not close. This one is a no from me.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Animal and lab work, not yet tested in people
Real results, but from animals or cells, not people. What works in a mouse often does not work the same way in a person. Nobody can patent this, so nobody would ever earn back the cost of a study in people. That is usually why there is none. The record on this one is set out below.
- Living longer2 animal or lab studies
- Testosterone and male hormones1 animal or lab study
34 of the 36 indexed goals have no study of any kind behind NDGA
No study in people, animals or cells on this page reports a result for these. That does not prove NDGA does nothing for them. It does mean anything you have heard about NDGA and one of these did not come from a study cited here.
Show full evidence
What is NDGA?
In male mice, it made them live longer at three different doses, and bigger doses did more. It never worked in females. It also harms the liver, which is why the plant it comes from was pulled from the supplement market.
NDGA is a plant compound from the creosote bush.
In people, the record that matters is about the liver, and it is bad. Chaparral, the herbal product made from the same plant, has been linked to cases of serious liver damage. Regulators acted on it. This is not a guess about risk. There is no ageing data in people.
In mice, it has a rare strength. The same testing program repeated its lifespan result at three different doses, and bigger doses did more. Very few compounds manage that.
So it sits in an awkward spot. It has a real, repeated lifespan result in male mice. It has a known liver risk in people. And it has no ageing evidence in people at all.
One detail matters. It raised the typical lifespan, but not how long the longest-lived mice got. That is a different kind of result from 17-alpha-estradiol. Raising the typical lifespan without raising the longest usually means fewer mice died early. It does not mean ageing itself slowed.
How does NDGA work?
NDGA does many things at once, which makes it hard to say what is doing the work. It blocks a group of enzymes called lipoxygenases. It acts as an antioxidant. It has been reported to affect IGF-1 growth signalling and how the cell's power plants work. Its liver damage is blamed on breakdown products that form when parts of the molecule react with oxygen. That comes from the molecule's own shape, not from a dirty batch. So better manufacturing cannot fix it. A cream form called masoprocol was once approved for rough, scaly sun-damage patches on the skin. That is a local skin use and tells you nothing about the whole body getting a dose.
What have studies in people found about NDGA?
No ageing data in people. What we do have in people is a liver safety record. It comes from people using the herb, not from any trial.
- No study in people has looked at lifespan, healthy years or any ageing measure.
- Chaparral, the herbal product made from the same plant, has been linked to cases of serious liver damage.
- The liver damage comes from breakdown products of the molecule itself. So it is built into NDGA, not a manufacturing problem.
- A cream form was once approved for rough, scaly sun-damage patches on the skin. That skin use tells you nothing about a dose that reaches the whole body.
What this does not tell you: Here is what we have. In male mice only, the typical lifespan went up, and this was repeated. How long the longest-lived mice got did not change. In people, the compound has a known record of liver damage and no ageing data. Raising the typical lifespan but not the longest usually means fewer early deaths, not slower ageing. That is a much weaker claim than the headline makes it sound.
The state of the research
Here is the part most coverage skips. Several of this program's most reliable wins made male mice live longer and did nothing for female mice. This is not a case of too few mice. The female results simply do not move. Nobody knows why. Guesses include that males and females break the drug down differently, that they die of different things, or that their hormones differ. In practice, when a headline says a compound makes mice live longer, it often means half the mice. It usually does not say which half.
NDGA also shows a difference this site cares about and most coverage blurs. Median lifespan is the age by which half the animals have died. Maximal lifespan is how long the longest-lived ones get. A compound that raises the median but not the maximum has most likely removed something that was killing animals early. That is useful. It is not the same as slowing ageing. 17-alpha-estradiol raised both at its higher dose. NDGA raised only the median, at all three doses tested.
The Interventions Testing Program is the US government's mouse testing program, run by the National Institute on Aging. It runs every test at three separate labs at once. It uses mice bred to be genetically mixed, so a result cannot come from one odd strain. It tests males and females. Its groups are big enough to spot about a 10 percent change in lifespan. It publishes its failures next to its wins. Nothing else in ageing research does all of that. So its results count for more than one lab's result. And when it fails to repeat a result, that matters just as much as a win.
The evidence, in charts
Fig. 1a · how many people
0people have taken this in any study cited here
0 people · 0 studies in people
What this page cites instead is 2 animal studies. None of them gave the compound to a person.
Counted from the list of sources on this page. We draw this chart only when a study in people is cited. An empty one is the answer, not a gap in the page.
Fig. 1b · evidence mix
None of the 2 sources here are studies in people.
- Animal study · done in animals2100%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
Sources here come from just two years, 2014 and 2016.
Too few different years on this page to draw a timeline. The newest source on file is from 2016, more than five years ago. Research on it may have gone quiet.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Supplement
- Molecule weight
- 302.4 Da. A lignan, not a peptide.
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: Not asserted for the mouse dietary regimen. Fed continuously in the diet in the lifespan studies.
No amino acid sequence is on file for NDGA, which is expected: a supplement is not built from amino acids.
The studies we cite
- Animal study2016Longer lifespan in male mice treated with a weakly estrogenic agonist, an antioxidant, an alpha-glucosidase inhibitor or a Nrf2-inducer
In mice, the result held at three different doses, which is rare. Male mice lived longer on average at the first dose, at a dose three times lower and at one three times higher. Bigger doses did more. The longest-lived mice did not live any longer. Females got nothing.
Interventions Testing Program. The male-specific extension of median lifespan by NDGA was replicated at the original dose and at doses threefold lower and threefold higher. Effects were dose dependent and male specific, and there was no effect on maximal lifespan. Replication across three doses in the same programme is unusual and is the strongest thing about this compound.
- Animal study2014Acarbose, 17-alpha-estradiol, and nordihydroguaiaretic acid extend mouse lifespan preferentially in males
In mice, this is the first report of the male-leaning lifespan result. NDGA, acarbose and 17-alpha-estradiol all helped males more than females.
The original report of the male-preferential lifespan effect, alongside acarbose and 17-alpha-estradiol.
Common questions
Has NDGA been tested in people?
Not in any study cited here. In male mice, it made them live longer at three different doses, and bigger doses did more. It never worked in females. It also harms the liver, which is why the plant it comes from was pulled from the supplement market.
What is the NDGA dosage?
No human dose established. No published study on this page has given this compound to people and reported a result. 2 animal studies, no human study
Is NDGA FDA-approved?
Not approved for any use as a medicine that works through the whole body. Masoprocol, a skin cream version, held an approval for actinic keratoses, rough scaly patches on sun-damaged skin. Chaparral, the herbal product from the same plant, has drawn official warnings over liver damage.
Is NDGA safe to take?
No. This is one of the clearest answers on the site. The herbal product made from the same plant has been linked to serious liver damage. The harm comes from breakdown products of the molecule itself, not from contamination. So a purer product does not fix it. And there is no ageing evidence in people to weigh against that risk.
How strong is the lifespan result?
Unusually well repeated, and narrower than it sounds. In male mice, it raised the typical lifespan at three separate doses, and bigger doses did more. Almost nothing manages that. It did not raise how long the longest-lived mice got. It did nothing in females.
Why does median versus maximal matter?
Raising the typical (median) lifespan without raising the longest (maximal) lifespan usually means fewer animals died early. It does not mean ageing slowed. Both are useful findings, but they support different claims. Headlines often report the first as if it were the second.