Apigenin

Apigenin is a flavonoid found in chamomile, parsley, celery, and a handful of other plants. Most people take it at night for sleep and to take the edge off an overactive mind, usually 50 mg about an hour before bed. It's the bioactive that gives chamomile tea its mild sedative reputation, but in a concentrated form that actually does something measurable.

The other reason it's gotten attention recently is its effect on NAD+. Apigenin inhibits CD38, the main enzyme that breaks NAD+ down, so it indirectly raises NAD+ levels in tissues. That's made it popular in longevity stacks alongside things like NMN or NR, where the goal is to keep NAD+ high enough for sirtuins and mitochondrial repair pathways to work properly. The two use cases (sleep and longevity) overlap conveniently because the dose is similar.

Deep-dive

Mechanism: NAD+ and CD38. CD38 is an enzyme that consumes NAD+ to produce signaling molecules, and its expression climbs steeply with age, which is one of the main reasons NAD+ levels drop as you get older. Escande and colleagues at the Mayo Clinic showed that apigenin inhibits CD38 with an IC50 around 10 micromolar, raises intracellular NAD+, and decreases protein acetylation in cells. In obese mice, oral apigenin raised NAD+, improved glucose and lipid handling, and increased SIRT1 activity. A follow-up rat study on high-fat-diet obesity confirmed the same NAD+/SIRT1 axis effect: apigenin improved insulin resistance, lowered TNF-alpha and IL-6, and raised NAD+ in liver and adipose. In diabetic kidney disease models, apigenin restored the NAD+/NADH ratio and Sirt3 activity by suppressing CD38. Worth flagging: apigenin is not a selective CD38 inhibitor, and the effective tissue concentrations seen in animal models are higher than what's reliably achieved in humans through oral dosing. Real-world NAD+ effects in humans are extrapolated, not measured.

Mechanism: GABA and sleep. Apigenin binds to the benzodiazepine site on the GABA-A receptor, which is the same site that drugs like diazepam target, but with much weaker affinity. The literature on what it does there is genuinely mixed. Some studies in mice show clear anxiolytic effects without sedation or motor impairment. Studies in rats show sedation but the effect isn't always blocked by flumazenil, the standard benzodiazepine antagonist, suggesting it's also working through other channels (possibly direct chloride channel activation or reductions in cortisol). An in vitro study on cortical neurons actually found apigenin reduced GABA-evoked currents, which is the opposite of a benzodiazepine. The clean story you sometimes read ("apigenin is like a natural Xanax") is oversimplified. What you can say is that the human clinical data on chamomile extract, which contains apigenin as the main bioactive, consistently shows modest but real benefits for sleep quality and anxiety.

Human evidence. Most clinical trials use chamomile extract rather than purified apigenin. A randomized trial in elderly nursing home residents found 200 mg of chamomile extract twice daily for 28 days significantly improved sleep quality. A pilot trial in adults with primary insomnia found 270 mg twice daily showed modest improvements in daytime functioning and sleep latency, though it didn't reach statistical significance. A double-blind trial in generalized anxiety disorder found chamomile extract significantly reduced anxiety symptoms. The signal is real but modest, and it's hard to attribute it solely to apigenin since chamomile contains other bioactives (luteolin, bisabolol, others). There are essentially no large RCTs on isolated apigenin in humans.

Bioavailability is the elephant in the room. Oral apigenin is poorly absorbed. Pharmacokinetic studies put oral bioavailability around 30% in animal models with significant first-pass metabolism, and the direct human study found only about 0.5% of an apigenin dose was recoverable as urinary metabolites, with peak plasma concentrations very low. Half-life is around 2.5 hours. This is why most marketed supplements are 50 mg, 100 mg, or higher: you need a substantial oral dose to push enough into circulation to do anything. Liposomal and micellar formulations exist and improve absorption considerably, but the data is mostly in vitro. Practical implication: dose at night with some fat (a small handful of nuts, a teaspoon of olive oil) and don't expect a 5 mg dose to do anything.

Anti-inflammatory and antioxidant effects. Beyond CD38, apigenin downregulates NF-kB signaling, reduces TNF-alpha and IL-6, suppresses iNOS, and activates Nrf2-mediated antioxidant pathways. Hepatoprotective effects have been shown across multiple liver disease models including NAFLD and fibrosis. These mechanisms are also implicated in its skin benefits (UV protection, reduced dermatitis-like inflammation) and its proposed cardiovascular and neuroprotective effects. The pattern is common to many flavonoids and the human translation isn't well established, so don't take this as evidence apigenin will fix specific organ disease in humans.

Cancer and breast tissue. Apigenin has shown anti-cancer effects across many cancer types in cell and animal models, including induction of apoptosis, cell cycle arrest, and inhibition of angiogenesis. The most relevant animal work for women is a rat study showing apigenin delayed the development of mammary tumors accelerated by medroxyprogesterone acetate (a synthetic progestin used in some HRT regimens), apparently by inhibiting progestin-induced VEGF. This sounds like a clean win for women on combination HRT, but the same researchers later cautioned that high-dose pure apigenin alongside HRT could interact with progestin metabolism in unpredictable ways, and recommended caution rather than enthusiasm. Translation: getting apigenin from food is fine and probably protective. Adding a high-dose supplement on top of HRT is not currently advisable based on the available evidence.

Hormonal effects, men and women. Apigenin is a weak aromatase inhibitor in vitro (IC50 around 20 micromolar), which is the marketing basis for its use in testosterone-boosting stacks. The relevant doses to actually inhibit aromatase meaningfully through oral dosing are well above what people typically take, and in humans there's no controlled evidence apigenin shifts testosterone or estradiol. In animal models of high-fat-diet obesity, apigenin improved testosterone synthesis through reduced ER stress in Leydig cells, but again, this is a stressed system being restored toward normal, not enhancement of an already-healthy one. Other in vitro work shows apigenin can actually inhibit testosterone biosynthesis enzymes at higher concentrations. The honest read: it's not a reliable testosterone booster. Stop buying it for that.

Women specifically. Apigenin acts as a partial agonist at estrogen receptors, with stronger affinity for ER-beta than ER-alpha, which is the same selectivity profile as several beneficial phytoestrogens. In low-estrogen environments it can act estrogenic, in high-estrogen environments it can act anti-estrogenic by competing with estradiol at the receptor. In practical terms this means it has a wider safety margin than a pure estrogen agonist, and may explain why it shows benefit in both ovarian cancer prevention models and in postmenopausal symptom contexts. A review on female reproductive health covers effects on folliculogenesis, ovarian protection from oxidative damage, and PCOS-relevant changes (LH down, FSH up, progesterone up, testosterone down in PCOS rat models). Most of this is preclinical. The cleanest practical takeaway for women: at typical doses (50-100 mg), the sleep and anti-inflammatory effects are the same ones men get, with the additional caveat about HRT interaction noted above.

Older adults. This is where the longevity case is strongest. CD38 expression rises with age, NAD+ falls, sirtuin activity drops. Apigenin extends lifespan in C. elegans and shows benefit in flies and mice. The human data doesn't yet exist, but the mechanistic case (CD38 inhibition, NAD+ preservation) is reasonable. The caveat is that you're betting on a mechanism, not on demonstrated outcomes in humans.

Dosage:

Standard dose: 50 mg, taken 30-60 minutes before bed. This is what most products land on and matches the dose used in the majority of supplement formulations targeting sleep and longevity

Higher dose: 100-200 mg if 50 mg doesn't produce a noticeable effect on sleep latency or quality. Some longevity protocols run 200 mg daily, though the marginal benefit above 100 mg is uncertain and the risk of CYP-mediated drug interactions rises with dose.

Take with fat. Apigenin is fat-soluble and poorly water-soluble. Taking with a small amount of dietary fat (nuts, olive oil, dark chocolate, full-fat yogurt) significantly improves absorption. An empty stomach or a low-fat meal is the worst case.

Timing: Evening dose, ideally before the wind-down period rather than right at lights-out, since plasma peak is 1-2 hours after ingestion.

Forms: Standard apigenin powder or capsules are what most people use. Liposomal or phytosome formulations have meaningfully better bioavailability and are worth the price difference if you can find a reputable brand. Chamomile extract standardized to apigenin content (look for 1.2% apigenin) is a reasonable alternative and has more direct human clinical data behind it, but you'll need a higher dose of the extract to hit the equivalent apigenin amount

Stacks: Pairs naturally with magnesium glycinate for sleep, and with NMN/NR for the longevity angle since apigenin protects the NAD+ that those compounds boost.

Here's what you can expect:

For sleep, most people notice a slight reduction in sleep latency and a calmer pre-sleep mental state within the first week. It's not a sledgehammer like trazodone or zolpidem. The effect is closer to a deeper relaxation that makes falling asleep easier rather than knocking you out. Some people feel nothing for the first few nights and then notice the cumulative effect after a week or two. Others notice it immediately. A small minority don't respond at all, which is consistent with the mixed pharmacology at GABA receptors.

For the longevity/NAD+ effects, you won't feel anything subjectively. This is purely a mechanistic bet. If you're taking it for that reason alongside NMN or NR, the value is in protecting the NAD+ those compounds raise rather than producing a felt effect.

For anxiety, the effect is mild. If you have clinically diagnosed anxiety disorder, this is not your tool. If you have garden-variety end-of-day mental noise that interferes with sleep, it can take the edge off.

Side effects & risks:

Sedation and drowsiness are the dose-limiting side effects. Take it at night, not during the day.

GI discomfort including nausea or mild stomach upset, especially at higher doses or on an empty stomach. Resolves with food and with dose reduction

Allergic reactions: Apigenin is concentrated in chamomile, which is in the Asteraceae family. Anyone with a ragweed, daisy, or chrysanthemum allergy should be cautious or skip it entirely. Reactions range from mild skin irritation to, rarely, anaphylaxis

CYP3A4, CYP2C9, and CYP1A2 inhibition. This is the most clinically relevant interaction concern. Apigenin inhibits these cytochrome enzymes, which metabolize a long list of drugs. Concrete examples: warfarin, statins, many SSRIs, calcium channel blockers, several cancer chemotherapies, and oral steroids. If you're on prescription medication with a narrow therapeutic index, particularly warfarin, run apigenin past your prescriber first

Anticoagulant and antiplatelet interaction. Beyond the CYP issue, apigenin has mild antiplatelet effects of its own. Stack with caution if you're already on aspirin, clopidogrel, or an anticoagulant

HRT interaction: As covered above, women on combination estrogen-progestin HRT should be cautious about high-dose pure apigenin until the interaction is better characterized. Dietary intake from food is not a concern

Hyperthyroidism: Apigenin has weak thyroid-modulating effects in some preclinical work.

Pregnancy and breastfeeding: Skip it. The estrogen receptor activity, weak aromatase inhibition, and lack of safety data make this an easy decision

Long-term safety data is limited. Most human trials of chamomile extract run 4-12 weeks. There are no long-term randomized trials of pure apigenin at supplemental doses. The toxicity profile in animal models is favorable, but the absence of long-term human data is a real limitation

Sold as a dietary supplement in most countries