Apigenin dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Apigenin is sold as a way to protect your NAD by blocking CD38, an enzyme that uses NAD up. That rests on one 2013 paper in cells and obese mice. No study in people has ever checked whether apigenin changes CD38 or NAD. After a big serving of parsley, blood levels in people only reach a tiny amount.
Evidence grade for Apigenin: Preliminary. The rule: studied in people, but no published study has had people take it. The sum on this page: 1 human study where nobody was given it. 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.
1 human study where nobody was given it
1 effects reported, 1 unwanted, by people using it, not a trial
Goal pages: Fat loss and metabolism, Muscle and strength, Ageing and longevity
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.
Apigenin is a plant compound found in parsley, celery and chamomile. It is sold as a pill to protect NAD, by blocking an enzyme called CD38 that uses NAD up. It is also why chamomile is said to calm you down. It is a supplement, not a drug.
What people take it for
- Protecting NAD with age.
- Better sleep.
- Making NMN last longer.
What studies in people showed
The only human study measured how much gets into the blood. 11 adults ate a big serving of parsley. Blood levels peaked at a tiny amount after about seven hours and were gone in a day. No study in people has measured NAD or CD38 after apigenin. In cells and obese mice, it raised NAD. The strong ageing results in mice came from a different drug called 78c, which is not for sale.
What people report
Reports, not study results
The good
- We have not collected user reports on this one yet.
The bad
- No safety study in people at supplement doses has been published, so its side effects are unknown.
Where these come from: We have no user reports. These lines come from the studies on this page.
My bottom line
Eat your parsley. As an NAD pill, it is a guess stacked on a mouse study. I would not pay for it.
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.
- Lasting longer, stamina1 animal or lab study
- Blood sugar and insulin1 animal or lab study
- Cell energy and mitochondria1 animal or lab study
33 of the 36 indexed goals have no study of any kind behind Apigenin
No study in people, animals or cells on this page reports a result for these. That does not prove Apigenin does nothing for them. It does mean anything you have heard about Apigenin and one of these did not come from a study cited here.
Show full evidence
What is Apigenin?
Apigenin is sold as a way to protect your NAD by blocking CD38, an enzyme that uses NAD up. That rests on one 2013 paper in cells and obese mice. No study in people has ever checked whether apigenin changes CD38 or NAD. After a big serving of parsley, blood levels in people only reach a tiny amount.
Apigenin has a growing spot in NAD marketing. The pitch is that instead of pouring more NAD boosters in, you plug the leak. CD38 is the enzyme that uses up NAD, and it gets more active with age. So blocking it should save NAD. That reasoning is sound, and the enzyme science is real. The evidence that apigenin does it in a person is missing.
The CD38 story rests on solid work in mice. A 2016 paper showed that CD38 gets more active with age. It showed CD38 is needed for NAD to fall with age, and for the power-plant problems in cells that come with that. It also showed CD38 is the main enzyme that breaks down NMN in the body. That last point matters. It means CD38 breaks down the NAD supplements as well as NAD itself.
Apigenin came in through a 2013 paper from the same lab. It found that quercetin and apigenin both block CD38. In cells, apigenin raised NAD and changed how proteins were tagged inside the cell. In obese mice, it raised NAD and improved some parts of how they handled sugar and fat.
The part that gets left out is what came next. When the same lab wanted to test the CD38 idea properly in ageing mice, they did not use apigenin. They used 78c, a drug built for the job and described as very strong and precise. It reversed the fall in NAD with age. It improved blood sugar control, muscle function, exercise ability and heart function. The strongest evidence for blocking CD38 came from a drug that is not on sale.
And the human data is not kind. 11 healthy adults ate one big serving of blanched parsley, 2 g per kilogram of body weight. That held about 66 micromoles of apigenin. Blood apigenin peaked at 127 nanomoles per litre after about seven hours. It was gone by 28 hours. Only 0.22 percent of what they ate showed up in the urine.
How does Apigenin work?
CD38 is an enzyme on the surface of cells, and one of the main users of NAD in the body. It gets more active with age. It is also the main enzyme that breaks down NMN in the body. Blocking it raises NAD inside cells without adding any booster. That in turn makes sirtuins more active and changes how proteins are tagged. Apigenin blocks CD38 in a dish, which is the whole reason it is used here. It is also a plant compound with a long list of other effects seen in a dish. It fights oxidation, it binds calming receptors in the brain called GABA-A, and it is reported to calm inflammation. Most of those effects show up at levels far above what a pill reaches in human blood.
What have studies in people found about Apigenin?
One study in 11 healthy adults, measuring how much apigenin reaches the blood after eating it in food. No study in people has measured CD38, NAD levels or any ageing result with apigenin.
- 11 healthy adults, one big serving of parsley with about 66 micromoles of apigenin: blood levels peaked at 127 nanomoles per litre at about 7 hours, were gone by 28 hours, and only 0.22 percent of the dose showed up in urine.
- No study in people has measured NAD in blood or tissue after apigenin.
- No study in people has measured CD38 activity after apigenin.
- No study in people has measured any health or function result related to ageing with apigenin.
- The health-sounding claims for apigenin come from cells and obese mice. The strongest CD38 result in mice used a different drug that is not for sale.
What this does not tell you: A one-time test in 11 people tells you how much of a compound gets into the blood. It tells you nothing about what it does there. People also eat apigenin in ordinary food, like parsley, celery and chamomile. So the real question for a supplement is whether a capsule gets levels that food does not. Nobody has studied that either. Tiny blood levels, set against an effect only shown in a dish, is the exact gap this page exists to point out.
The state of the research
The CD38 idea is one of the better ideas in NAD science. It should not be thrown out along with the supplement. Blocking the enzyme that uses up NAD is cleaner than flooding the system with boosters. That is especially true because CD38 is also the main enzyme that destroys NMN in the body. So someone taking NMN and a CD38 blocker may be doing two things that affect each other. In ageing mice, a strong and precise blocker reversed the fall in NAD. It improved blood sugar control, muscle function, exercise ability and heart function. That is a strong animal result for the strategy.
It is not a result for apigenin. The drug used was 78c, built for the job and not for sale. The 2013 apigenin paper came earlier. It used cells and obese mice, and it reported better sugar and fat handling, not an ageing result.
The blood level gap is the practical problem. In people, after a big serving of parsley, blood apigenin peaked at 127 nanomoles per litre and was gone within a day. Almost none of the dose was found intact. Blocking an enzyme in a dish is usually shown at much higher levels than that. Nobody has published that comparison for apigenin and CD38 in a person. Until someone measures CD38 or NAD in people taking apigenin, the claim that a capsule protects your NAD is a stretch. It jumps across three species and a huge gap in dose levels.
Apigenin in food is a different question from apigenin in a capsule sold on an NAD claim. Nothing here argues against parsley or chamomile.
Almost all consumer writing about this pathway blends three kinds of claim into one. Keeping them apart is most of the work. A blood marker claim says a product raises NAD in the blood. That is easy to show, and for several of these products it is simply true. A middle claim says it moves something between a blood marker and a symptom, such as how stiff the arteries are. A health claim says a person walks further, remembers more, gets fewer cancers or lives longer. A product can be solid on the first kind and have nothing at all on the third. That is where most of this pathway sits. No published study in people of any NAD booster has shown a real health benefit, with one exception on this list. That exception is nicotinamide in skin cancer. It works by helping sun-damaged skin repair its DNA, not through anything to do with ageing.
The evidence, in charts
Fig. 1a · how many people
11people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| Annals of Nutrition and Metabolism 2006 | 11 | 100% |
The whole total is one study of 11. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
1 of 4 sources here is a study in people. The rest are not.
- Study in people · done in people125%
- Animal study · done in animals375%
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
The studies cover 4 different years, 2006 to 2018, counted from the list of sources on this page. The newest source on file is from 2018, 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
- 270.2 Da
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: No reliable human elimination half-life has been established. In the parsley bioavailability study, plasma apigenin peaked around seven hours after an oral bolus and had fallen below the detection limit within about a day.
No amino acid sequence is on file for Apigenin, which is expected: a supplement is not built from amino acids.
The studies we cite
- Study in people2006Bioavailability of apigenin from apiin-rich parsley in humans
Very little apigenin from food reaches your bloodstream. 11 healthy adults ate one large serving of blanched parsley. Apigenin in the blood peaked about seven hours later at a very low level, and the amount varied enormously from person to person. It was undetectable a day later. Only about two parts in a thousand of what they ate came out in urine. This measured where the compound goes in the body. It did not test whether apigenin does anything.
The only human number on this page, and it is a pharmacokinetic one. 11 healthy adults aged 23 to 41 consumed a single oral bolus of blanched parsley at 2 g per kilogram of body weight, corresponding to 65.8 plus or minus 15.5 micromoles of apigenin. Mean peak plasma apigenin was 127 plus or minus 81 nanomoles per litre at 7.2 hours, with wide variation between people, falling below the 2.3 nanomole detection limit by 28 hours. Urinary recovery was 0.22 percent of the ingested dose. The authors conclude that a small portion of dietary apigenin reaches the circulation.
- Animal study2013Flavonoid apigenin is an inhibitor of the NAD+ ase CD38: implications for cellular NAD+ metabolism, protein acetylation, and treatment of metabolic syndrome
In a dish and in mice. This is the paper the apigenin-for-NAD market is built on. Quercetin and apigenin both blocked CD38. In cells, blocking CD38 raised NAD, and apigenin changed how proteins were tagged. In obese mice, apigenin raised NAD and improved some parts of sugar and fat handling. There is no human data.
The paper the entire apigenin-for-NAD market is built on. Cell culture plus obese mice. The authors characterise quercetin and apigenin as CD38 inhibitors, show that pharmacological CD38 inhibition raises intracellular NAD, and that treating cell cultures with apigenin decreases global protein acetylation including acetylation of p53 and RelA-p65. Apigenin given to obese mice increased NAD, decreased global protein acetylation and improved several aspects of glucose and lipid homeostasis. No human data.
- Animal study2016CD38 Dictates Age-Related NAD Decline and Mitochondrial Dysfunction through an SIRT3-Dependent Mechanism
In mice. CD38 gets more active with age. Mice need it for NAD to fall with age, and for the power-plant problems in cells that follow. It is also the main enzyme that breaks down NMN in the body. That matters for anyone taking NMN, because it names the enzyme that destroys it.
The mechanistic foundation, in mice. CD38 expression and activity increase with age, CD38 is required for the age-related NAD decline and mitochondrial dysfunction via a pathway mediated at least in part by SIRT3, and CD38 is the main enzyme degrading the NAD precursor NMN in vivo. That last finding matters for anyone taking NMN, because it identifies the enzyme that destroys it.
- Animal study2018A Potent and Specific CD38 Inhibitor Ameliorates Age-Related Metabolic Dysfunction by Reversing Tissue NAD(+) Decline
In mice. This is the strongest evidence for blocking CD38, and it did not use apigenin. A strong, precise blocker called 78c reversed the fall in NAD with age. It improved blood sugar control, muscle function, exercise ability and heart function, in mice that aged normally or fast. An author holds a patent on CD38 blockers. 78c is not for sale and has no human data.
The strongest evidence for the CD38 strategy, and it was not generated with apigenin. 78c, a highly potent and specific thiazoloquinazolinone CD38 inhibitor, reversed age-related NAD decline and improved glucose tolerance, muscle function, exercise capacity and cardiac function in mouse models of natural and accelerated ageing. The effects depended on tissue NAD levels and were reversed by inhibiting NAD synthesis. A declared conflict: an author holds a patent on the use of CD38 inhibitors for metabolic disease. 78c is not commercially available and has no human data.
Common questions
Has Apigenin been tested in people?
Not in a completed trial cited here. 1 human study where nobody was given it. Apigenin is sold as a way to protect your NAD by blocking CD38, an enzyme that uses NAD up. That rests on one 2013 paper in cells and obese mice. No study in people has ever checked whether apigenin changes CD38 or NAD. After a big serving of parsley, blood levels in people only reach a tiny amount.
What is the Apigenin dosage?
No human dose established. No published study on this page has given this compound to people and reported a result. 1 human study where nobody was given it
Is Apigenin FDA-approved?
Found naturally in common foods, and sold over the counter as a supplement. Not an approved drug for any use, and no health claim about NAD, CD38 or ageing has been approved.
Does apigenin raise NAD in humans?
Nobody has measured it. There is no study in people that looked at apigenin and NAD, or apigenin and CD38. The NAD rises credited to apigenin were measured in cells and in obese mice.
Is apigenin a CD38 inhibitor?
In a dish, yes. A 2013 paper showed that, alongside quercetin. Nobody has tested whether it blocks CD38 at the levels a pill reaches in human blood. After a big serving of parsley, those peaked at 127 nanomoles per litre.
Should I take apigenin with NMN or NR?
The theory makes sense. CD38 is the main enzyme that breaks down NMN in the body, so blocking it should make a booster last longer. No study in people has tested that combination on anything, including blood NAD. It is an idea with a reason behind it, not a plan with evidence.
What about 78c?
78c is the strong, precise CD38 blocker that gave the big results in ageing mice. It reversed the fall in NAD and improved blood sugar control, muscle function, exercise ability and heart function. It is not for sale, has no human data, and is not apigenin. Marketing that quotes those mouse results next to an apigenin product is giving one compound credit for another's results.
Is apigenin safe?
It is a normal part of parsley, celery and chamomile, and people eat it without trouble. That is some comfort about the amounts in food. Supplement doses are far higher, and no safety study in people has been published. In a dish, apigenin also binds calming receptors in the brain. It is the compound usually credited for chamomile's sleepy reputation. So mixing it with sedatives is worth raising with a doctor.