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Key takeaways
• Fisetin is a senolytic — it clears senescent cells (1). Apigenin is a CD38 inhibitor — it protects NAD from age-related degradation (2,3).
• Apigenin’s longevity identity is younger than fisetin’s. The CD38-inhibition mechanism was established by Escande in 2013 (2); NAD-decline pharmacology has become a major longevity focus since Bryan Johnson’s public advocacy.
• Neither has strong published human RCT data for a clinical longevity endpoint. Apigenin’s CD38 pharmacology is well characterised preclinically but human NAD-preservation trials are limited (7).
• Apigenin has poor bioavailability — comparable to or worse than fisetin. Extensive first-pass conjugation is the primary limiting factor.
• Dietary sources are distinct — apigenin is concentrated in parsley, chamomile, celery, and thyme, whereas fisetin is concentrated in strawberries and apples.
• The mechanisms are complementary — stacking with fisetin is common in longevity practice and has no known negative interaction.
Quick answer
Fisetin and apigenin are two flavonoids targeting distinct longevity mechanisms. Fisetin clears senescent cells (senolytic); apigenin inhibits CD38, an NAD-degrading enzyme whose activity increases with age (2,3). Neither has strong published human RCT evidence for a clinical longevity endpoint, but both have coherent preclinical mechanistic support. Apigenin has entered the longevity conversation more recently, driven partly by the rising interest in NAD preservation as a longevity strategy. Combining fisetin and apigenin is defensible and common; the mechanisms are non-overlapping. If forced to choose, fisetin has the more established senolytic evidence base; apigenin has the more specific CD38-NAD mechanistic story. For the full fisetin context, see our complete clinician’s guide.
Chemistry and origin
Fisetin (3,3′,4′,7-tetrahydroxyflavone) is a flavonol — the flavonoid subclass that includes quercetin and kaempferol. Concentrated in strawberries.
Apigenin (4′,5,7-trihydroxyflavone) is a flavone — a distinct flavonoid subclass. Concentrated in parsley (roughly 220 mg/100 g fresh weight), chamomile flowers, celery, thyme, and oregano. It is the flavonoid most associated with the calming effect of chamomile tea.
Both are polyphenolic antioxidants with anti-inflammatory activity. Both are dietary flavonoids present in ordinary healthy diets at low levels. The mechanistic identities that make them longevity supplement candidates are distinct.
Different mechanisms — senolytic vs CD38 inhibition
Fisetin — senolytic clearance
Fisetin’s senolytic mechanism, established by Yousefzadeh 2018 (1), targets senescent cells through simultaneous SCAP interference. See our dedicated senolytic article for detail.
Apigenin — CD38 inhibition and NAD preservation
Apigenin’s longevity mechanism is different. CD38 is a cell-surface and intracellular enzyme that degrades NAD+ — the coenzyme central to mitochondrial energy production, sirtuin activity, and DNA repair. CD38 activity increases with age, and this increase is a major driver of the well-documented age-related decline in tissue NAD levels (3). Camacho-Pereira and colleagues demonstrated that CD38 knockout in mice preserves NAD levels and preserves mitochondrial function with age. Apigenin inhibits CD38 at concentrations achievable in tissue and, in mouse models, reduces the age-related decline in NAD (2).
This makes apigenin conceptually similar to NAD precursor supplements (NMN, NR) but through a different route: instead of adding NAD substrate, it slows the enzymatic degradation of existing NAD. The two strategies are theoretically complementary.
Why the mechanisms are complementary
Fisetin removes senescent cells that were producing SASP factors and inflammation. Apigenin preserves NAD levels in the remaining cells, supporting mitochondrial function and sirtuin activity. Different problems, different tools. A biology-informed longevity stack might reasonably include both.
Human clinical evidence
Apigenin’s trials
Apigenin has been studied in a modest number of small human trials — mostly for anxiety (chamomile-based supplementation), inflammatory markers, and cardiometabolic biomarkers. A 2024 systematic review documented mixed but modestly positive effects on inflammatory markers and cardiometabolic biomarkers (7). Dedicated NAD-preservation trials with apigenin as the intervention are limited; the CD38-inhibition-to-NAD-preservation-to-clinical-benefit chain has more preclinical support than human trial data.
Fisetin’s trials
Fisetin’s human trials are the six ongoing or completed pulsed-protocol trials (7). AFFIRM remains unreported. When AFFIRM publishes, the comparison changes.
The honest picture
Neither compound has strong current published human RCT evidence for a clinical longevity endpoint. Both have coherent preclinical mechanistic support. The comparison at this stage is more about which mechanism you prefer to bet on than which compound has demonstrated benefit.
Bioavailability
Both compounds have poor oral bioavailability. Apigenin has a peak plasma concentration typically below 100 ng/ml after a 400 mg oral dose, with rapid glucuronidation and sulphation limiting systemic exposure of the parent compound (4). Fisetin’s bioavailability is comparably poor, as documented in the Krishnakumar 2022 study (6). Formulation strategies exist for both but neither has commercially mature bioavailability-enhanced products with strong human PK data.
Dose and dosing
|
Aspect |
Fisetin |
Apigenin |
|
Mechanism |
Senolytic |
CD38 inhibitor / NAD preservation |
|
Typical daily dose |
100–500 mg (continuous) or 20 mg/kg pulsed |
50–300 mg daily continuous |
|
Dietary sources |
Strawberries, apples, persimmons |
Parsley, chamomile, celery, thyme, oregano |
|
Bioavailability |
Poor |
Poor |
|
Human RCT with clinical endpoint |
None yet published |
Mixed small trials on inflammatory markers (7) |
|
Cost per month |
Modest |
Modest |
Both are typically taken continuously with a fatty meal. Neither has an established pulsed protocol equivalent to the fisetin senolytic protocol.
When to choose which
For NAD preservation and mitochondrial support: apigenin is the more direct choice via CD38 inhibition. Combining apigenin with an NAD precursor (NMN or NR) is the mechanistically coherent NAD-strategy stack.
For senolytic activity specifically: fisetin is the more direct choice.
For preclinical evidence maturity: fisetin has the more established senolytic evidence base (2018 Yousefzadeh); apigenin’s CD38 identity is younger (2013 Escande).
For dietary integration: both have accessible dietary sources. Fisetin from strawberries is easier to increase in most diets than apigenin from parsley (which requires large quantities of a herb rarely eaten in bulk).
The stacking case
Combining fisetin and apigenin is mechanistically coherent. Both are flavonoids with poor bioavailability but non-overlapping mechanisms. Same meal, same fat co-ingestion. No known interaction. Practical stacking: apigenin at 100–300 mg daily with breakfast (continuous); fisetin at either continuous 250–500 mg daily or pulsed 20 mg/kg × 2 days per month.
For the specific NAD-strategy stack, apigenin combines naturally with NMN or NR — the precursor supplies the substrate, apigenin protects it from CD38-mediated degradation. This is a coherent and increasingly common longevity approach.
What we still don't know
• Whether apigenin at supplement doses meaningfully raises tissue NAD levels in humans. The mechanistic case is strong; the human PK-to-clinical-benefit chain is not yet demonstrated.
• Whether apigenin plus fisetin produces additive human benefit. Not tested.
• Whether apigenin has meaningful senolytic activity at supplement doses. Preclinical hints exist but the compound is not a primary senolytic.
• Whether the CD38-NAD strategy will prove clinically superior to direct NAD precursor supplementation or whether they are complementary.
Bottom line
Fisetin and apigenin target different longevity mechanisms — fisetin clears senescent cells; apigenin inhibits CD38 to preserve NAD. Neither has strong current published human RCT evidence for a clinical longevity endpoint, but both have coherent preclinical support. The mechanisms are complementary and combining the two is defensible. For NAD-preservation strategy, apigenin is the more mechanistically direct choice, ideally combined with NMN or NR. For senolytic activity, fisetin is the more established choice. For the fisetin context, see our complete clinician’s guide.
Frequently asked questions
Is apigenin a senolytic?
Not primarily. Some preclinical work has explored apigenin’s senolytic activity but its principal longevity identity is CD38 inhibition and NAD preservation.
Can I take fisetin and apigenin together?
Yes. Same meal is fine. No known interaction.
Should I take apigenin with NMN?
Yes, if NAD preservation is your goal. The combination is mechanistically coherent — NMN provides NAD substrate; apigenin protects it from CD38 degradation.
Is apigenin from chamomile tea enough?
Chamomile tea contains apigenin but at levels well below supplement doses. Chamomile tea has other legitimate uses (mild calming effect) but is not a source of longevity-relevant apigenin exposure.
Which is safer?
Both have favourable safety profiles at supplemental doses. Neither has documented serious adverse events at typical dose ranges.
References
1. Yousefzadeh MJ, Zhu Y, McGowan SJ, et al. Fisetin is a senotherapeutic that extends health and lifespan. EBioMedicine. 2018;36:18-28. https://pmc.ncbi.nlm.nih.gov/articles/PMC6197652/
2. Escande C, Nin V, Price NL, et al. Flavonoid apigenin is an inhibitor of the NAD+ase CD38. Diabetes. 2013;62(4):1084-1093. https://pubmed.ncbi.nlm.nih.gov/23172919/
3. Camacho-Pereira J, Tarragó MG, Chini CCS, et al. CD38 dictates age-related NAD decline and mitochondrial dysfunction through an SIRT3-dependent mechanism. Cell Metab. 2016;23(6):1127-1139. https://pubmed.ncbi.nlm.nih.gov/27304511/
4. Salehi B, Venditti A, Sharifi-Rad M, et al. The therapeutic potential of apigenin. Int J Mol Sci. 2019;20(6):1305. https://pmc.ncbi.nlm.nih.gov/articles/PMC6472148/
5. Ali F, Rahul, Naz F, Jyoti S, Siddique YH. Health functionality of apigenin: a review. Int J Food Prop. 2017;20(6):1197-1238. https://www.tandfonline.com/doi/full/10.1080/10942912.2016.1207188
6. Krishnakumar IM, Jaja-Chimedza A, Joseph A, et al. Enhanced bioavailability and pharmacokinetics of a novel hybrid-hydrogel formulation of fisetin. J Nutr Sci. 2022;11:e74. https://doi.org/10.1017/jns.2022.72
7. AFFIRM: Alleviation by Fisetin of Frailty, Inflammation, and Related Measures in Older Women (NCT03430037). ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT03430037
8. Kelder RJ, van der Kolk-Vegter AJ, Gambelunghe A, et al. Apigenin and cardiometabolic biomarkers: a systematic review of human trials. Food Funct. 2024;15:2801-2820. https://pubs.rsc.org/en/content/articlelanding/2024/fo/d3fo05023h