Apigenin is a naturally occurring flavonoid concentrated in chamomile, parsley, and celery that has attracted attention for its calming, antioxidant, and other biological properties. Before adding a high-dose apigenin supplement to your routine, however, there is a pharmacology question worth understanding: apigenin interacts with the cytochrome P450 (CYP450) enzyme system, the liver’s primary machinery for breaking down most prescription and over-the-counter drugs.
When a flavonoid like apigenin inhibits a CYP enzyme, the drugs that depend on that enzyme for clearance can accumulate to higher-than-expected blood concentrations. The three enzymes most relevant to apigenin are CYP1A2, CYP2C9, and CYP3A4. Together these enzymes handle a substantial share of commonly prescribed medications. This article explains the mechanisms, summarizes the available evidence, and identifies who should exercise the most caution. These statements have not been evaluated by the FDA; this is informational, not medical advice.
Key Takeaways
- Apigenin inhibits CYP1A2, CYP2C9, and CYP3A4 in vitro: the three liver enzymes responsible for clearing a large portion of commonly prescribed drugs.
- The highest-risk drug categories are warfarin (CYP2C9-dependent), CYP3A4-dependent statins such as simvastatin and lovastatin, and benzodiazepines such as midazolam and alprazolam.
- Most supporting evidence is from in vitro studies; human clinical pharmacokinetic data on apigenin-drug interactions is limited, so real-world magnitude of effect remains uncertain.
- Stacking apigenin with other sedatives (including melatonin, benzodiazepines, and alcohol) may compound CNS depression and warrants caution.
- Dietary apigenin from chamomile tea or parsley is unlikely to reach pharmacologically inhibitory concentrations; the concern is primarily relevant to high-dose concentrated supplement forms.
CYP450 Enzymes: The Liver's Drug-Processing System
Cytochrome P450 enzymes are a superfamily of proteins concentrated primarily in the liver and small intestine. Their core function is oxidative metabolism: converting lipophilic compounds, including drugs, plant molecules, and hormones, into more water-soluble metabolites the kidneys can excrete. Block one of these enzymes and you slow the clearance of every drug substrate that depends on it.
The clinical importance of CYP inhibition is well recognized in pharmacology. When a second compound (whether a prescription drug, a food component, or a botanical supplement) occupies or blocks a CYP enzyme, the affected drug’s half-life can lengthen and plasma concentration can rise above the intended therapeutic range, increasing adverse-effect risk without any change in dose. Herb-drug interactions operating through this metabolic mechanism are an active area of research, and the CYP system is one of the routes by which botanical compounds can alter drug pharmacokinetics.
Apigenin and CYP1A2
CYP1A2 is one of the major hepatic enzymes and is responsible for metabolizing caffeine, theophylline, clozapine, olanzapine, and several antidepressants and cardiovascular agents. Early in vitro work on dietary flavonoids demonstrated that structurally related compounds can both serve as substrates for and inhibitors of multiple CYP isoforms, including CYP1A2 [2]. Because apigenin is a flavone with hydroxyl groups at the 4′, 5, and 7 positions, it shares the scaffold features associated with CYP binding in this compound class.
Research note: In rats given chamomile tea to drink for four weeks, liver CYP1A2 activity fell to 39% of control (p<0.05). The EMA assessors said this rat finding must be taken into account for chamomile products. No human data on this effect were available [19].
More targeted research has examined how human family 1 CYP enzymes (CYP1A1, CYP1A2, and CYP1B1) directly oxidize apigenin [3]. This substrate-enzyme relationship is relevant because, in a lab study of the human CYP1A2 enzyme, apigenin was among the potent inhibitors, so it could in principle slow the metabolism of CYP1A2-dependent drugs, which has not been tested in people [9]. Separately, apigenin has been shown to inhibit the CYP monoxygenase branch of the arachidonic acid cascade [4], indicating that its CYP-related effects extend across more than one enzymatic context.
Apigenin and CYP2C9: The Warfarin Concern
CYP2C9 is the primary enzyme responsible for metabolizing S-warfarin, the more pharmacologically active enantiomer of the widely used anticoagulant. It also clears a range of NSAIDs including ibuprofen and celecoxib, several oral hypoglycemics such as glipizide and tolbutamide, and the antihypertensive losartan. In vitro studies of flavones, including apigenin, have found inhibitory activity against CYP2C9 across multiple members of this compound class [5][6].
In lab assays, apigenin inhibited the liver enzyme CYP2C9 that handles losartan and diclofenac, at low micromolar concentrations
Apigenin blocked CYP2C9 in lab assays, which is a reason for caution but not proof of a drug interaction in people.
In vitro only. A separate recombinant-enzyme study found apigenin inhibited CYP2C9-mediated diclofenac hydroxylation with Ki values at or below 2.2 micromolar. A lower IC50 means a lower concentration blocks the enzyme by half. Source: Wang et al., Pharmacology 2016; Si et al., Drug metabolism and disposition 2009
Data table
| Item | Value |
|---|---|
| Losartan, human liver microsomes | 4.10 micromol/L |
| Losartan, recombinant CYP2C9 | 7.61 micromol/L |
| Losartan, rat liver microsomes | 11.07 micromol/L |
| Diclofenac, human CYP2C9 | 9.51 micromol/L |
| Diclofenac, rat CYP2C11 | 15.51 micromol/L |
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For chamomile tea, the human evidence is limited to one case report and one small crossover trial. In 8 healthy volunteers, tea slightly lengthened prothrombin time while chamomile extract capsules did not reach significance, and neither change reached the predefined threshold for clinical significance [15][18].
The structural features of flavonoids that determine CYP2C9 inhibitory potency, particularly the degree of hydroxylation and methylation on the flavone ring, have been explored in intestinal epithelial cell models [7]. Apigenin’s three free hydroxyl groups influence its binding affinity to CYP active sites. For anyone on warfarin, a CYP2C9 inhibitor would matter in principle, but apigenin’s CYP2C9 inhibition has only been shown in enzyme assays (for example, losartan metabolism in human liver microsomes), not in people taking warfarin [5][6].
Apigenin and CYP3A4: The Broadest Interaction Risk
CYP3A4 is the most widely implicated drug-metabolizing enzyme, responsible for clearing an estimated 30 to 50 percent of all pharmaceuticals. Its substrate list includes simvastatin, lovastatin, midazolam, alprazolam, triazolam, cyclosporine, tacrolimus, and many others. Research specifically examining structurally diverse flavonoids found that multiple compounds in this chemical class inhibit CYP3A4, with binding affinity varying by substituent pattern on the core flavone scaffold [8].
Because of CYP3A4’s extraordinarily broad substrate profile, inhibition here carries the widest practical implications. For individuals combining an apigenin supplement with a prescribed benzodiazepine (for example, taking a chamomile-derived supplement alongside alprazolam for anxiety) there is a theoretical risk of enhanced and prolonged sedation. For those on certain statins whose clearance is CYP3A4-dependent, elevated drug exposure raises the risk of myopathy. The CYP3A4 concern is separate from apigenin’s GABA-A activity, which is unsettled: in cell work apigenin on its own inhibited GABA activation and did not act through the benzodiazepine site. Combining it with sedatives is still worth discussing with a clinician [10][11].
Drug Categories That Warrant the Most Caution
Three categories stand out based on their CYP enzyme dependencies and narrow therapeutic windows. First, anticoagulants: warfarin’s reliance on CYP2C9 for S-enantiomer clearance means any CYP2C9 inhibitor can unpredictably raise INR. Second, CYP3A4-dependent statins: lovastatin and simvastatin are highly dependent on CYP3A4 for first-pass and systemic clearance; accumulation is associated with myopathy and, in severe cases, rhabdomyolysis. Pravastatin and rosuvastatin, which are less CYP3A4-reliant, carry lower theoretical interaction risk. Third, benzodiazepines and related sedative-hypnotics: midazolam, triazolam, and alprazolam are well-established CYP3A4 substrates, and concurrent sedatives, including melatonin and alcohol, could compound CNS depression through additive mechanisms.
Metabolic enzyme inhibition is one recognised route through which botanical supplements can alter conventional drug pharmacokinetics. This concern is not unique to apigenin across the flavonoid class, but apigenin’s growing availability as a standalone supplement at doses far exceeding typical dietary exposure, commercial products range from 50 mg to 450 mg per serving, makes the interaction risk more concrete than it would be from trace amounts consumed through food.
Interpreting the Evidence: In Vitro Limits and Real-World Relevance
Virtually all of the data supporting apigenin’s CYP-inhibitory profile comes from in vitro studies: experiments in cell-free enzyme preparations or cell lines rather than in living humans. Concentrations used in vitro sometimes exceed what is achievable through food or even supplementation. How close supplement exposure comes to the lab concentrations is unknown: enzyme screens used 10 micromolar, while plasma apigenin peaked at 127 nmol/l after 11 healthy adults ate blanched parsley, and pure apigenin was poorly absorbed in healthy men [12][13][14].
Molecular modeling and docking studies have further characterized the structural basis of CYP3A4 flavonoid binding [8], and cell-based work has clarified how hydroxylation pattern modulates inhibitory activity [7]. Multiple independent research efforts examining flavonoids across different enzyme isoforms have arrived at consistent inhibitory signals for CYP1A2 [2][3][4], CYP2C9 [5][6], and CYP3A4 [8]. What remains limited is well-powered human pharmacokinetic data with apigenin specifically. Until such data exist, the in vitro signal provides the primary rational basis for precaution, and that signal is reproducible across multiple laboratories and methodologies.
A Note on the Evidence
The evidence for apigenin’s CYP inhibitory effects comes predominantly from in vitro studies, and robust human clinical pharmacokinetic data are lacking; real-world effect sizes remain uncertain. Individuals taking warfarin, benzodiazepines, CYP3A4-dependent statins, narrow-therapeutic-window antiepileptics, or other medications cleared by CYP1A2, CYP2C9, or CYP3A4 should consult a qualified healthcare provider before starting or stopping apigenin supplements. These statements have not been evaluated by the FDA; apigenin is not intended to diagnose, treat, cure, or prevent any disease.
Frequently Asked Questions
What is CYP enzyme inhibition and why does it matter for supplements?
CYP enzymes in the liver break down most drugs into metabolites the body can excrete. When a compound inhibits one of these enzymes, affected drugs clear more slowly and can accumulate to higher blood concentrations, raising both effect and adverse-event risk without any change in dose. Herb-drug interactions operating through CYP inhibition are a recognized pharmacological concern documented across botanical compounds [1].
Which CYP enzymes does apigenin specifically affect?
In vitro research demonstrates inhibitory activity at CYP1A2, CYP2C9, and CYP3A4. Studies examining dietary flavonoids broadly found consistent inhibitory signals across these isoforms [2], while apigenin-specific research has further characterized its interaction with CYP1A2 as both a substrate and inhibitor [3] and its inhibition of CYP monoxygenase pathways [4].
Why is warfarin particularly concerning with apigenin?
Warfarin’s S-enantiomer, the pharmacologically dominant form, is metabolized almost exclusively by CYP2C9. Apigenin’s inhibitory activity at CYP2C9, documented in in vitro studies of apigenin and related flavones [5][6], could slow warfarin clearance and raise INR without any change in dose, increasing bleeding risk unpredictably. Anyone on anticoagulant therapy should not start apigenin supplements without medical guidance.
Are all statins equally at risk from CYP3A4 inhibition?
No. Statins differ substantially in their CYP3A4 dependence. Simvastatin and lovastatin rely heavily on CYP3A4 for first-pass and systemic clearance, so inhibition of that enzyme, which structurally diverse flavonoids including apigenin have been shown to produce in vitro [8]could significantly raise their plasma concentrations. Pravastatin, rosuvastatin, and fluvastatin use other clearance routes and carry lower theoretical interaction risk.
Does eating chamomile or parsley create these drug interaction risks?
Probably not at typical dietary amounts, but the evidence is thin. Chamomile tea itself has been linked to one warfarin case report, in a woman who drank 4-5 cups a day, used a chamomile lotion and was also taking amiodarone. The EU herbal monograph also notes reported CYP450 interactions in kidney transplant patients taking high doses of oral chamomile for about two months. Whether supplement-level apigenin reaches pharmacologically relevant plasma levels has not been shown [15][16][12].
Can I take apigenin with melatonin or alcohol safely?
This question involves two separate mechanisms. Apigenin’s action at GABA-A receptors is unsettled (in cell work it inhibited GABA activation on its own and did not act through the benzodiazepine site), and apigenin has not been shown to cause sedation in people, so any additive effect with melatonin or alcohol is a precaution, not a measured interaction [10][11][17]. Apigenin may additionally slow the clearance of compounds metabolized by the enzymes it inhibits. This is an area where consulting a pharmacist or physician is advisable rather than self-experimenting, particularly at supplement doses.
References
- Wang T et al. Herb-drug interaction potential of Astragali Radix: a metabolic perspective. Drug metabolism reviews (2025). PMID 39692050
- Breinholt VM et al. In vitro investigation of cytochrome P450-mediated metabolism of dietary flavonoids. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association (2002). PMID 11955666
- Nagayoshi H et al. Oxidation of Naringenin, Apigenin, and Genistein by Human Family 1 Cytochrome P450 Enzymes and Comparison of Interaction of Apigenin with Human P450 1B1.1 and Scutellaria P450 82D.1. Chemical research in toxicology (2023). PMID 37783573
- Steuck M et al. Food Polyphenol Apigenin Inhibits the Cytochrome P450 Monoxygenase Branch of the Arachidonic Acid Cascade. Journal of agricultural and food chemistry (2016). PMID 27933871
- Wang Z et al. Inhibitory Effect of Apigenin on Losartan Metabolism and CYP2C9 Activity in vitro. Pharmacology (2016). PMID 27287328
- Si D et al. Mechanism of CYP2C9 inhibition by flavones and flavonols. Drug metabolism and disposition: the biological fate of chemicals (2009). PMID 19074529
- Karancsi Z et al. Effect of hydroxylated and methylated flavonoids on cytochrome P450 activity in porcine intestinal epithelial cells. Acta veterinaria Hungarica (2023). PMID 37141048
- Mitrasinovic PM et al. On the inhibition of cytochrome P450 3A4 by structurally diversified flavonoids. Journal of biomolecular structure & dynamics (2022). PMID 34060409
- Shimada H et al. Differential mechanisms for the inhibition of human cytochrome P450 1A2 by apigenin and genistein. Journal of biochemical and molecular toxicology (2010). PMID 20806393
- Campbell EL et al. The dietary flavonoids apigenin and (-)-epigallocatechin gallate enhance the positive modulation by diazepam of the activation by GABA of recombinant GABA(A) receptors. Biochemical pharmacology (2004). PMID 15451406
- Goutman JD et al. Flavonoid modulation of ionic currents mediated by GABA(A) and GABA(C) receptors. European journal of pharmacology (2003). PMID 12586201
- Fei Lin et al. Inhibitory effect of Selaginella doederleinii hieron on human cytochrome P450. Frontiers in Pharmacology (2023). PMID 36874034
- Hellen Meyer et al. Bioavailability of Apigenin from Apiin-Rich Parsley in Humans. Annals of Nutrition and Metabolism (2006). PMID 16407641
- Borges G et al. Absorption, distribution, metabolism and excretion of apigenin and its glycosides in healthy male adults. Free radical biology & medicine (2022). PMID 35452808
- R. Segal Warfarin interaction with Matricaria chamomilla. Canadian Medical Association Journal (2006). PMID 16636327
- European Medicines Agency (HMPC) European Union herbal monograph on Matricaria recutita L., flos (EMA/HMPC/55843/2011). European Medicines Agency (HMPC) (2015). source
- Mastrofini GF et al. Modulating stress and sleep through a multi-compound dietary supplement: a randomized, double-blind, placebo-controlled trial. Journal of the International Society of Sports Nutrition (2026). PMID 42829807
- Kimura R et al. The Acute Effect of Chamomile Intake on Blood Coagulation Tests in Healthy Volunteers: A Randomized Trial. The journal of applied laboratory medicine (2024). PMID 38300838
- European Medicines Agency (HMPC) Assessment report on Matricaria recutita L., flos and aetheroleum (draft, EMA/HMPC/55837/2011). European Medicines Agency (HMPC) (2014). source
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.