Supplements: Apigenin
Chamomile extract (360mg apigenin) improved sleep quality in clinical trials (Hieu 2019, PMID 31299742). Chamomile tea provides only 5-10mg apigenin per cup versus 50-500mg in supplements.
| Measure | Value | Unit | Notes |
|---|---|---|---|
| Evidence Tier | 3 | tier | Weak — sleep/anxiety has moderate chamomile data; NAD+ and aromatase claims lack direct human RCTs |
| Sleep Study Dose | 360 | mg | Apigenin from chamomile extract used in Hieu 2019 meta-analysis trials |
| Chamomile Tea Apigenin | 5–10 | mg/cup | Very low relative to therapeutic supplement doses of 50-500mg |
| Supplement Dose Range | 50–500 | mg | Common supplemental range; sleep benefit studied at higher end of this range |
| Parsley Apigenin Content | 4500 | mg/100g dry | Highest dietary source; fresh parsley ~215mg/100g; not practical for therapeutic dosing |
| CD38 Inhibition Potency | theoretical | at food doses | NAD+ elevation via CD38 inhibition demonstrated in vitro; human data at supplement doses absent |
Apigenin is a naturally occurring flavonoid (4′,5,7-trihydroxyflavone) found at high concentrations in chamomile flowers, parsley, and celery. It has attracted significant research interest for three mechanistically distinct properties, each supported by a different depth of evidence.
The Three Proposed Mechanisms
GABA-A Receptor Modulation: Apigenin binds to benzodiazepine sites on GABA-A receptors with low affinity — producing mild anxiolytic and sedative effects without the full agonism seen with pharmaceutical benzodiazepines. This is the most clinically documented mechanism, supported by multiple chamomile extract trials.
CD38 Inhibition and NAD+: CD38 is an enzyme that catabolizes NAD+. By inhibiting CD38, apigenin theoretically preserves NAD+ levels through a pathway distinct from NR or NMN supplementation. This mechanism is demonstrated in vitro and in some animal models but lacks human clinical confirmation at supplement doses.
Aromatase Inhibition: Apigenin has measurable but weak aromatase inhibitory activity in cell assays. Whether this translates to meaningful estrogen reduction in living humans at the doses found in supplements remains undemonstrated.
| Mechanism | Claimed Effect | Evidence Quality | Active Dose | Food Equivalent | Recommendation |
|---|---|---|---|---|---|
| GABA-A modulation | Sleep onset, anxiety reduction | Moderate (chamomile RCTs) | 360mg apigenin | 36-72 cups chamomile tea | Most supported use |
| CD38 inhibition | NAD+ elevation | Weak (in vitro only) | Unknown in humans | Not achievable from food | Speculative at this time |
| Aromatase inhibition | Lower estrogen, more free T | Insufficient (cell studies) | Unknown in humans | Not achievable from food | Not a primary use case |
| GABA-A (anxiety) | Daytime anxiolytic | Moderate (chamomile RCTs) | 220-540mg extract | 22-54 cups chamomile tea | Modest effect expected |
| Antioxidant | General oxidative stress | Weak (indirect) | Varies | Moderate at dietary intake | Not a primary reason to supplement |
| Anti-inflammatory | COX inhibition | Moderate (in vitro/animal) | High doses | Not achievable from food | More relevant as food component |
Food Sources vs. Supplement Doses
Chamomile tea yields approximately 5-10mg apigenin per cup — effective for relaxation rituals but roughly 35-70× below the doses used in sleep clinical trials. Dried parsley contains up to 4,500mg/100g, but no one eats therapeutic quantities of parsley. Supplemental apigenin standardized to 50-500mg or high-apigenin chamomile extracts close this gap.
Practical Protocol
For sleep: 100-500mg apigenin (or equivalent chamomile extract) taken 30-60 minutes before bed. The GABA-A mechanism does not produce tolerance at these doses in the same way pharmaceutical agents do. For NAD+ support, the evidence does not yet support choosing apigenin over better-studied NR or NMN.
Related Pages
Sources
- Hieu TH et al. Therapeutic efficacy and safety of chamomile for state anxiety, generalized anxiety disorder, insomnia, and sleep quality: a systematic review and meta-analysis of randomized trials and quasi-randomized trials. Phytother Res. 2019;33(6):1604-1615.
- Zick SM et al. Preliminary examination of the efficacy and safety of a standardized chamomile extract for chronic primary insomnia: a randomized placebo-controlled pilot study. BMC Complement Altern Med. 2011;11:78.
- Schultz SA et al. CD38 as a regulator of cellular NAD: a novel potential pharmacological target for metabolic conditions. Curr Pharm Des. 2016;22(18):2741-2751.
Frequently Asked Questions
Does apigenin actually improve sleep?
The evidence base is for chamomile extract, not isolated apigenin. A 2019 meta-analysis of randomized trials found chamomile extract improved subjective sleep quality and reduced anxiety. The active dose in these trials was approximately 360mg apigenin-equivalent. Chamomile tea provides only 5-10mg per cup — far below the studied dose.
Can apigenin raise NAD+ levels?
Apigenin inhibits CD38, an enzyme that degrades NAD+, in cell culture studies. This is mechanistically distinct from NMN or NR (which are NAD+ precursors). However, no human RCTs have confirmed that supplement doses of apigenin meaningfully raise NAD+ in vivo. The pathway is plausible but unproven at practical doses.
Is apigenin a testosterone booster?
Apigenin weakly inhibits aromatase, the enzyme that converts testosterone to estrogen. In cell studies it reduces aromatase activity. Human data confirming meaningful testosterone increases at supplement doses do not exist. The aromatase effect is too weak and indirect to categorize apigenin as a testosterone booster.
When should I take apigenin for sleep?
Based on chamomile trial protocols, taking apigenin 30-60 minutes before bedtime is standard. Doses of 100-500mg standardized chamomile extract or isolated apigenin are used. It pairs well with magnesium glycinate for a non-pharmacological sleep stack without next-day sedation.