Apigenin
apigenin
A dietary flavonoid promoted to preserve NAD⁺ by inhibiting the enzyme CD38.
TypeSupplement / dietary
The grade answers: What does the human evidence support for: CD38 inhibition / NAD⁺ support?
Grade
C
Limited
The grade rates evidence quality — it is not advice to take or buy.
- Class
- Flavonoid
- Primary use
- CD38 inhibition / NAD⁺ support
- Evidence strength
- low
- Last reviewed
- 2026-07-01
Bottom line
A neat theory — block the enzyme that burns through NAD⁺ — supported mainly by lab and animal work. Direct human longevity evidence is essentially absent.
What the evidence says
Apigenin is a flavonoid (parsley, chamomile, celery) studied as a CD38 inhibitor; since CD38 consumes NAD⁺ and rises with age, inhibiting it is proposed as a way to preserve NAD⁺ — a different angle from NAD⁺ precursors like NMN. The evidence is largely preclinical, with some small human work on anxiety/sleep (as in chamomile) unrelated to the NAD⁺ claim. There are no human trials showing it raises NAD⁺ or affects aging outcomes. Grade C: interesting mechanism, minimal direct human evidence, and poor bioavailability like most flavonoids.
Key studies
- [1]
Apigenin as a CD38 inhibitor and NAD⁺ metabolism · preclinical
Preclinical basis for the NAD⁺-preservation idea.
Open on PubMed ↗ - [2]
Apigenin pharmacology and bioavailability (review) · review
Low absorption complicates translation to humans.
Open on PubMed ↗ - [3]
Mechanism
Inhibits CD38, an NAD⁺-degrading enzyme, potentially slowing NAD⁺ decline; also has general antioxidant, anti-inflammatory and mild anxiolytic flavonoid effects.
Safety
Consumed as a dietary flavonoid with good tolerability at food levels; concentrated supplement safety is less characterised, and flavonoids can interact with drug-metabolising enzymes.
Dosage context
No established human 'NAD⁺-preserving' dose; supplement products vary and bioavailability is low. Much of the interest is extrapolated from cell and animal studies.
Examples of application
- Present in parsley, chamomile and celery.
- As a supplement, the CD38/NAD⁺ rationale is largely preclinical.
- One to watch rather than bank on; absorption is low.
From the field
Apigenin is the 'stop burning NAD⁺' counterpart to the 'add more NAD⁺' precursors — clever on paper, almost entirely preclinical in practice. Grade C, and one to watch rather than to bank on.