Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Relax Ingredients & Drug Interactions

by L.A. Naturals

Relax label
See full label image
Liquid Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Relax against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Relax is a dietary supplement by L.A. Naturals with 7 active ingredients. Its ingredients are commonly taken for asthma and breathing problems, cough and bronchitis, smoking cessation aid.Based on those ingredients, 1,190 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Vanuatu Kava, Chamomile, fresh Valerian. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Relax by L.A. Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with Relax by L.A. Naturals — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Relax by L.A. Naturals

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 7 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label doesn't break down how much of each component you get.

This product has 7 ingredients, including a proprietary blend. The active components are fresh lobelia, fresh pulsatilla, chamomile, fresh valerian, hops, vanuatu kava, and passion flower — all herbs traditionally used to promote relaxation.

The liquid also contains grain alcohol and deionized water as inactive ingredients.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: relaxation and calm.
  • We looked for evidence on: Anxiety, Generalized anxiety disorder (GAD), Insomnia, Stress, Tension headache, muscle relaxation — and 1 related terms.
  • The strongest evidence on file: Valerian is rated "Possibly Effective" for Insomnia (Natural Medicines).
  • Also on file: Passion Flower is rated "Possibly Effective" for Pre-procedural anxiety, Insomnia.
  • Also on file: Kava is rated "Possibly Ineffective" for Generalized anxiety disorder (GAD).

Valerian has possibly effective evidence for insomnia, making it the only ingredient in this blend with established benefit for a relaxation-related condition. Passion flower is also possibly effective for insomnia and pre-procedural anxiety.

The rest — lobelia, pulsatilla, hops, and kava — either lack reliable evidence for relaxation or insomnia, or (in lobelia's case) is possibly ineffective for its traditional use in smoking cessation. Chamomile's effectiveness rating is not on file in our data.

The evidence, ingredient by ingredient Lobelia Pulsatilla German Chamomile Valerian Hops Kava Passion Flower

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 7 of the 7 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 7 of 7.
  • General safety write-ups exist for 7 of 7.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Lobelia carries serious toxicity concerns: it can cause nausea, vomiting, diarrhea, dizziness, tremors, and throat irritation at doses as low as 50 mg, and at 600 mg or higher can trigger sweating, rapid heart rate, seizures, dangerously low blood pressure, coma, or death. Fresh pulsatilla is a toxic gastrointestinal irritant that can damage the kidneys and cause severe skin irritation.

Kava has been linked to over 100 cases of liver damage, especially with prolonged use, and can cause drowsiness, tremors, memory problems, and in rare cases rhabdomyolysis. Valerian is generally well tolerated short-term but can cause dizziness, drowsiness, mental slowness, headache, stomach upset, and vivid dreams; stopping suddenly after long use can trigger withdrawal symptoms like rapid heart rate, anxiety, and insomnia.

Hops and passion flower typically cause drowsiness and mild side effects. Pregnancy and breastfeeding are not safe for lobelia (likely unsafe), pulsatilla (likely unsafe), valerian, hops, or kava; passion flower safety data in pregnancy is insufficient, so the risks aren't clear.

Side effects, ingredient by ingredient Lobelia Pulsatilla German Chamomile Valerian Hops Kava Passion Flower

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 6 of the 7 matched ingredients can interact with medications — Lobelia, Hops, Valerian, Passion Flower, Kava, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; lithium.
  • For scale: 1,191 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you take this, double-check any CNS depressants (sleep aids, anti-anxiety drugs, opioids, muscle relaxants) — kava raises this to Major severity. Also run through any drugs metabolized by the liver enzymes CYP2C19, CYP2C9, or CYP2E1, hepatotoxic medications, estrogens, and any drugs that rely on lithium-level balance.

Valerian can also interact with alcohol and alprazolam specifically. If you take any prescription medication at all, check it with our tool below before you start.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with some supporting evidence for its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

This blend is built on sedating herbs — good if you're looking for drowsiness, risky if you're already taking sedating medications or have liver concerns. Kava and lobelia carry the heaviest safety warnings.

Talk to your pharmacist before starting, especially if you take any prescription drugs, have liver disease, or are pregnant or nursing.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 7 of 7 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jul 25, 2014.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Relax, straight from the product label.

Brand L.A. Naturals
Barcode (UPC) 641356048614
Net contents 1 fl. Oz.; 30 mL
Market status On market
Date entered into DSLD Jul 25, 2014
DSLD ID 35233
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Kosher
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Relax by L.A. Naturals, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 mL
Maximum serving Sizes:
2 mL
Servings per container
30
UPC/BARCODE
641356048614
IngredientAmount% DV
Proprietary Blend0 NP--
fresh Lobelia0 NP--
fresh Pulsatilla0 NP--
Chamomile0 NP--
fresh Valerian0 NP--
Hops0 NP--
Vanuatu Kava0 NP--
Passion Flower0 NP--

Other ingredients: Grain Alcohol, deionized Water

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

SUGGESTED USE: 30-60 drops, 2-3 times per day or as needed in juice or water.

Shake well before using.

Precautions

WARNING: Do not take during pregnancy or while nursing.

Keep out of the reach of children.

General Statements

Plant # K-0001604

MADE IN THE USA

FAST ABSORPTION MEDICINAL BOTANICALS HERB FORMULA IN ALCOHOL

Supports Restful Sleep & Relaxation**

440 mg Herb Weight Equivalence

Herb Strength Ratio 1:2.4

Seals/Symbols

** These statements have not been evaluated by the FDA. This product is not intended to diagnose, cure, treat, or prevent any disease.

L.a.(TM)

K PARVE

FDA Statement of Identity

DIETARY SUPPLEMENT

Brand IP Statement(s)

~ Selectively Imported

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Relax by L.A. Naturals label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Relax label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Relax by L.A. Naturals

These are the 7 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 mL Dosage formLiquid Servings per container30 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Proprietary Blend

0 NP per serving

Other (inactive) ingredients: Grain Alcohol, Deionized Water. These complete the product’s ingredient list but are not active constituents.

Interaction report

Relax by L.A. Naturals Drug Interactions

Want to check YOUR meds against Relax?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1,190Drugs
248 Major 923 Moderate 19 Minor

Ingredients driving the most interactions

Vanuatu Kava 1,166
Chamomile 960
fresh Valerian 902
Hops 863
Passion Flower 836

Individual Drug Interactions

The ingredients in Relax interact with 1,190 drugs. Click any drug to see the details.

6 of the 7 ingredients in Relax interact with drugs. Each result below shows which ingredient is responsible. Vanuatu Kava Chamomile fresh Valerian Hops Passion Flower fresh Lobelia

Each ingredient & the kinds of drugs it affects

For each ingredient in Relax with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Vanuatu Kava12 drug types · 1,166 drugs

Cns Depressants

Combining kava with CNS depressants can have additive sedative effects.
Kava has CNS depressant effects. Concomitant use of kava with other CNS depressants can increase the risk of drowsiness and motor reflex depression. Clinical practice guidelines from a joint taskforce of the World Federation of Societies of Biological Psychiatry (WFSBP) and the Canadian Network for Mood and Anxiety Treatments (CANMAT) recommend that CNS depressants, including alcohol and benzodiazepines, not be used with kava.

Likelihood Probable Evidence A
Alcohol (Ethanol)

Combining kava with alcohol may increase the risk of sedation and/or hepatotoxicity.

Kava has CNS depressant effects. Concomitant use of kava with other CNS depressants can increase the risk of drowsiness and motor reflex depression. Additionally, kava has been associated with over 100 cases of hepatotoxicity. There is some concern that kava can adversely affect the liver, especially when used in combination with hepatotoxic drugs. Clinical practice guidelines from a joint taskforce of the World Federation of Societies of Biological Psychiatry (WFSBP) and the Canadian Network for Mood and Anxiety Treatments (CANMAT) recommend that alcohol not be used with kava.

Likelihood Possible Evidence A
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, kava might increase levels of CYP2C19 substrates.
In vitro research shows that kava significantly inhibits CYP2C19 enzymes. This effect has not yet been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, kava might increase levels of CYP2C9 substrates.
In vitro research shows that kava significantly inhibits CYP2C9 enzymes. This effect has not yet been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Kava might increase levels of CYP2E1 substrates.
In a clinical study in healthy volunteers, taking kava 1000 mg twice daily (containing a daily dose of 138 mg kavalactones) for 28 days inhibited the metabolism of CYP2E1 substrates.

Likelihood Probable Evidence B
Haloperidol (Haldol)

Combining kava and haloperidol might increase the risk of cardiovascular adverse effects and hypoxia.
Atrial flutter and hypoxia has been reported for a patient who received intramuscular injections of haloperidol and lorazepam after using kava orally. The side effects were attributed to kava-induced inhibition of CYP2D6, but might also have been related to additive adverse effects with the concomitant use of haloperidol, lorazepam, and kava.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, using kava with hepatotoxic drugs might increase the risk of liver damage.
Kava has been linked with over 100 cases of hepatotoxicity. Most cases occur with excessive and prolonged use. There is some concern that kava can adversely affect the liver, especially when used in combination with hepatotoxic drugs.

Likelihood Possible Evidence D
P-Glycoprotein Substrates

It is unclear if kava inhibits P-glycoprotein (P-gp); research is conflicting.
In vitro research shows that kava can inhibit P-gp efflux. However, a clinical study in healthy volunteers shows that taking kava standardized to provide 225 mg kavalactones daily for 14 days does not affect the pharmacokinetics of digoxin, a P-gp substrate. It is possible that the use of other P-gp substrates or higher doses of kava might still inhibit P-gp.

Likelihood Possible Evidence D
Ropinirole (Requip)

Taking kava with ropinirole might increase the risk for dopaminergic toxicity.
A case of visual hallucinations and paranoid delusions has been reported for a patient who used kava in combination with ropinirole. The adverse effects were attributed to kava-induced inhibition of CYP1A2, which may have reduced the metabolism of ropinirole, resulting in excessive dopaminergic stimulation.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

It is unclear if kava inhibits CYP1A2; research is conflicting.
Although in vitro research and a case report suggest that kava inhibits CYP1A2, more robust clinical evidence shows that kava has no effect on CYP1A2. In a clinical study in healthy volunteers, taking kava 1000 mg twice daily (containing a daily dose of 138 mg kavalactones) for 28 days had no effect on CYP1A2 activity.

Likelihood Unlikely Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

It is unclear if kava inhibits CYP1A2; research is conflicting.
In vitro research shows that kava extract significantly inhibits CYP2D6. However, clinical research shows that kava does not affect the metabolism of CYP2D6 substrates in humans.

Likelihood Unlikely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

It is unclear if kava inhibits CYP3AA; research is conflicting.
Although in vitro research suggests that kava inhibits CYP3A4, more robust clinical evidence shows that kava has no effect on CYP3A4. In a clinical study in healthy volunteers, taking kava 1000 mg twice daily (containing a daily dose of 138 mg kavalactones) for 28 days had no effect on CYP3A4 activity.

Likelihood Unlikely Evidence B
Vanuatu Kava full monograph & interactions

Chamomile9 drug types · 960 drugs

Cns Depressants

Theoretically, German chamomile might have additive effects when used with CNS depressants.
German chamomile has mild sedative effects. Theoretically, concomitant use with drugs with sedative properties can cause additive effects and side effects.

Likelihood Possible Evidence D
Contraceptive Drugs

Theoretically, large amounts of German chamomile might reduce the effectiveness of oral contraceptives.
In vitro, German chamomile has demonstrated antiestrogenic activity. Theoretically, concomitant use of large amounts of German chamomile might interfere with contraceptive drugs through competition for estrogen receptors.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, German chamomile might inhibit CYP2C9 and increase levels of drugs metabolized by these enzymes.
In vitro evidence shows that German chamomile might inhibit CYP2C9. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP2C9 in patients taking German chamomile.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, German chamomile might inhibit CYP2D6 and increase levels of drugs metabolized by these enzymes.
In vitro evidence shows that German chamomile might inhibit CYP2D6. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP2D6 in patients taking German chamomile.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, German chamomile might inhibit CYP3A4 and increase levels of drugs metabolized by these enzymes.
In vitro evidence shows that German chamomile might inhibit CYP3A4. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP3A4 in patients taking German chamomile.

Likelihood Possible Evidence D
Estrogens

Theoretically, large amounts of German chamomile might reduce the effectiveness of estrogens.
In vitro, German chamomile has demonstrated antiestrogenic activity. Theoretically, large amounts of German chamomile might interfere with hormone replacement therapy through competition for estrogen receptors.

Likelihood Possible Evidence D
Tamoxifen (Nolvadex)

Theoretically, large amounts of German chamomile might interfere with the activity of tamoxifen.
In vitro, German chamomile has demonstrated antiestrogenic activity.

Likelihood Possible Evidence D
Warfarin (Coumadin)

German chamomile might increase the effects of warfarin and increase the risk of bleeding.
In one case, a 70-year-old female taking warfarin developed retroperitoneal hematoma and bilateral recti muscle bleeding along with an INR of 7.9 following ingestion of German chamomile tea 4-5 cups daily and use of a topical chamomile-based lotion applied 4-5 times daily.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, German chamomile might inhibit CYP1A2 and increase levels of drugs metabolized by these enzymes.
In vitro and animal research shows that German chamomile might inhibit CYP1A2. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP1A2 in patients taking German chamomile.

Likelihood Possible Evidence D
Chamomile full monograph & interactions

fresh Valerian6 drug types · 902 drugs

Alcohol (Ethanol)

Valerian can have additive sedative effects when used concomitantly with alcohol.
Valerian has sedative effects. Theoretically, valerian might have an additive sedative effect when combined with alcohol. Excessive sedation has been reported in an alcohol-abusing individual who took valerian and Gingko biloba. However, the potential interaction between valerian and alcohol has been disputed in other research. Limited evidence suggests that a combination of valerian 160 mg and lemon balm 80 mg (Euvegal) does not cause further deterioration in reaction ability and reaction rate when taken with alcohol as compared to the effects of alcohol alone.

Likelihood Possible Evidence B
Alprazolam (Xanax)

Valerian can have additive sedative effects when used with alprazolam. Also, valerian in high doses might modestly increase alprazolam levels, though this is not likely to be clinically significant.
Valerian has sedative effects. Theoretically, valerian might cause additive sedation when combined with alprazolam. Also, a small pharmacokinetic study shows that taking valerian extract 1000 mg daily (providing 11 mg valerenic acid) might increase alprazolam levels by about 19%. This might be due to valerian's mild inhibition of cytochrome P450 3A4 (CYP3A4). Despite being statistically significant, this increase is not likely to be clinically significant.

Likelihood Possible Evidence B
Cns Depressants

Valerian can have additive sedative effects when used concomitantly with CNS depressant drugs.
Theoretically, concomitant use of valerian and drugs with sedative and anesthetic properties may cause additive therapeutic and adverse effects.

Likelihood Possible Evidence D
Glucuronidated Drugs

Valerian might weakly inhibit glucuronidation and increase concentrations of drugs metabolized by UGT1A1 and UGT2B7.
In vitro research shows that methanolic valerian extract and valerenic acid might competitively inhibit UDP-glucuronosyltransferase (UGT) 1A1 (UGT1A1) and UGT2B7.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Valerian does not seem to have a clinically relevant effect on levels of drugs metabolized by CYP2D6.
Although some in vitro evidence suggests that valerian affects CYP2D6, clinical pharmacokinetic (PK) studies show that valerian is unlikely to affect the CYP2D6 enzyme. In one PK study, taking valerian 1000 mg (providing about 11 mg valerenic acid) nightly for 14 days did not affect the metabolism of dextromethorphan, a CYP2D6 substrate. In another PK study, taking valerian 125 mg three times daily for 28 days did not affect metabolism of debrisoquine, an accepted CYP2D6 probe-substrate.

Likelihood Unlikely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Valerian does not seem to have a clinically relevant effect on levels of drugs metabolized by CYP3A4.
Although some in vitro evidence suggests that valerian extract might inhibit or induce CYP3A4, clinical pharmacokinetic (PK) studies show that valerian does not have a clinically significant effect on the CYP3A4 enzyme. In one PK study, taking valerian 125 mg three times daily for 28 days did not affect metabolism of midazolam, an accepted CYP3A4 probe-substrate. In another PK study, taking valerian 1000 mg (providing about 11 mg valerenic acid) nightly for 14 days modestly increases levels of alprazolam, a CYP3A4 substrate, suggesting mild inhibition of CYP3A4. However, this mild inhibition is unlikely to be clinically relevant.

Likelihood Possible Evidence B
fresh Valerian full monograph & interactions

Hops4 drug types · 863 drugs

Cns Depressants

Theoretically, concomitant use of hops with sedative drugs might cause additive sedation.
Some animal research shows that hops has sedative effects.

Likelihood Possible Evidence D
Estrogens

Theoretically, concomitant use of large amounts of hops might interfere with hormone replacement therapy due to competition for estrogen receptors.
In vitro research suggests that certain hops constituents can competitively bind to estrogen receptors. However, most hops extracts contain very small amounts of these constituents.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Hops extract does not seem to affect the metabolism of CYP1A2 substrates.
In vitro research suggests that flavonoid constituents of hops inhibit CYP1A2 enzyme activity. However, a pharmacokinetic study in healthy postmenopausal patients shows that taking a standardized extract of spent hops containing prenylated phenols, as 59.5 mg twice daily for 2 weeks, does not affect levels of caffeine, a CYP1A2 probe substrate.

Likelihood Unlikely Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, hops extract might alter metabolism of CYP3A4 substrates; however, this effect may not be clinically significant.
Animal research suggests that specific constituents of hops, called lupulones, can induce hepatic CYP3A4 enzyme activity. However, a pharmacokinetic study in healthy postmenopausal patients with normal metabolism shows that taking a standardized extract of spent hops containing prenylated phenols, as 59.5 mg twice daily for 2 weeks, decreases the concentration of alprazolam, a CYP3A4 probe substrate, by 7.6%. This reduction is unlikely to be clinically relevant.

Likelihood Possible Evidence D
Hops full monograph & interactions

Passion Flower3 drug types · 836 drugs

Cns Depressants

Concomitant use of passion flower with sedative drugs might cause additive effects and side effects.
Research in animals and humans shows that passion flower has sedative effects which can be additive when used with sedative medications like lorazepam.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, passion flower might decrease the effects of CYP3A4 substrates.
In vitro research suggests that passion flower can induce CYP3A4 enzymes, albeit to a much lower degree than rifampin, a known CYP3A4 inducer.

Likelihood Possible Evidence D
Organic Anion-Transporting Polypeptide Substrates (Oatp)

Theoretically, passion flower might reduce the bioavailability of OATP2B1 and OATP1A2 substrates.
In vitro research shows that the passion flower constituents apigenin and vitexin inhibit OATP2B1 and OATP1A2. This inhibition may be dose-dependent. One specific high-flavonoid passion flower extract (Valverde) seems to inhibit OATP2B1 and OATP1A2, while another extract with a lower flavonoid concentration (Arkocaps) shows less potent inhibition. OATPs are responsible for the uptake of drugs and other compounds into the body; however, the specific activities of OATP2B1 and OATP1A2 are not well characterized.

Likelihood Possible Evidence D
Passion Flower full monograph & interactions

fresh Lobelia1 drug type · 1 drug

Lithium

Lobelia is thought to have diuretic properties. Theoretically, due to these potential diuretic effects, lobelia might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
fresh Lobelia full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Relax, from the product label.

L.A. Naturals

See all L.A. Naturals products
Name
Palko Services
Street Address
4991 W. US Hwy 20
City
Michigan City
State
IN
ZipCode
46360
Pharmacist Counseling Corner

Relax by L.A. Naturals: Common Questions

Does Relax by L.A. Naturals interact with any medications?
Yes. Based on its ingredients, Relax has a known interaction with 1,190 medications, including 248 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Relax contains 7 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does this product have lithium interactions?
Yes — lobelia may reduce your kidneys' ability to clear lithium, potentially raising its levels, which could make side effects worse. If you're on lithium, talk to your pharmacist or doctor before taking this product.
Is it safe to take this if I'm pregnant or breastfeeding?
No — the safety data advises against it. Lobelia, pulsatilla, valerian, and kava are likely unsafe during pregnancy and lactation because of toxicity concerns. Passion flower safety isn't well established. Talk with your doctor or pharmacist for personalized advice.
What are the most common side effects?
Drowsiness, dizziness, and mental slowness are typical, along with headache and vivid dreams. Lobelia carries the biggest risk at even low doses: nausea, vomiting, diarrhea, tremors, and throat irritation. High doses of kava or lobelia can cause serious toxicity.
Can I take this with sleeping pills or anti-anxiety medication?
Not safely without talking to your pharmacist first. This blend contains multiple sedating herbs — valerian, kava, hops, and passion flower — all of which can add dangerous drowsiness and impaired reflexes on top of prescription sedatives. The kava interaction is the most serious (Major severity).
Is kava the same in this blend as it was before it was banned?
The ingredient here is vanuatu kava. While kava carries a lower hepatotoxicity risk than some other sources, it's still been linked to over 100 cases of liver damage worldwide. The data on file doesn't indicate whether this specific source is different from past concerns.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Relax label
Go deeper

The Full Monographs Behind Relax’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Lobelia

Interacts with 1 drug

Lobelia is a traditional herb once used for breathing problems and to help people quit smoking, but reliable evidence supporting these uses is lacking. It can be toxic in higher amounts, cau...

Read the full Lobelia monograph → Herb & supplement monograph

Pulsatilla

Pulsatilla is a flowering plant in the buttercup family that is most often used today in homeopathic (highly diluted) preparations. The fresh plant is toxic and irritating, so it must never...

Read the full Pulsatilla monograph → Herb & supplement monograph

German Chamomile

Interacts with 960 drugs

German chamomile is a widely used herbal remedy taken mainly as a tea for calming, sleep, and digestive complaints. Early research suggests possible benefits for mild anxiety and some skin o...

Read the full German Chamomile monograph → Herb & supplement monograph

Valerian

Interacts with 902 drugs

Valerian is an herb whose root is widely used as a natural sleep aid and for calming nerves. The evidence is mixed and often weak, so it may help some people sleep but does not work reliably...

Read the full Valerian monograph → Herb & supplement monograph

Hops

Interacts with 863 drugs

Hops are most often used for sleep and mild anxiety, frequently combined with valerian, but the human evidence is limited and not very strong. They are generally well tolerated when used sho...

Read the full Hops monograph → Herb & supplement monograph

Kava

Interacts with 1,166 drugs

Kava is a Pacific Island plant traditionally used to promote relaxation and ease anxiety, and some studies suggest it may help mild anxiety. However, kava has been linked to rare but serious...

Read the full Kava monograph → Herb & supplement monograph

Passion Flower

Interacts with 836 drugs

Passion flower is a traditional calming herb that many people use for anxiety and sleep. Early studies hint it may help with mild anxiety and restlessness, but the evidence is limited and mo...

Read the full Passion Flower monograph →
Sources

Sources & How We Checked

Relax's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 166 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Lobelia 6 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  3. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  4. McChargue DE, Collins FL Jr, Cohen LM. Effect of non-nicotinic moist snuff replacement and lobeline on withdrawal symptoms during 48-h smokeless tobacco deprivation. Nicotine Tob Res 2002;4:195-200. PubMed
  5. Stead LF, Hughes JR. Lobeline for smoking cessation. Cochrane Database Syst Rev 2000;2:CD000124. PubMed
  6. Plakun, A. L., Ambrus, J., Bross, I., Graham, S., Levin, M. L., and Ross, C. A. Clinical factors in smoking withdrawal: preliminary report. Am J Public Health Nations.Health 1966;56(3):434-441. PubMed

See these in context on the Lobelia monograph →

Pulsatilla 3 references
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

See these in context on the Pulsatilla monograph →

German Chamomile 15 references
  1. Subiza J, Subiza JL, Hinojosa M, et al. Anaphylactic reaction after the ingestion of chamomile tea; a study of cross-reactivity with other composite pollens. J Allergy Clin Immunol 1989;84:353-8. PubMed
  2. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  3. Viola H, Wasowski C, Levi de Stein M, et al. Apigenin, a component of Matricaria recutita flowers, is a central benzodiazepine receptors-ligand with anxiolytic effects. Planta Med 1995;61:213-6.
  4. van Ketel WG. Allergy to Matricaria chamomilla. Contact Dermatitis 1982;8:143. PubMed
  5. van Ketel WG. Allergy to Matricaria chamomilla. Contact Dermatitis 1987;16:50-1. PubMed
  6. Hormann HP, Korting HC. Evidence for the efficacy and safety of topical herbal drugs in dermatology: part I: anti-inflammatory agents. Phytomedicine 1994;1:161-71. PubMed
  7. Avallone R, Zanoli P, Puia G, et al. Pharmacological profile of apigenin, a flavonoid isolated from Matricaria chamomilla. Biochem Pharmacol 2000;59:1387-94. PubMed
  8. Kassi E, Papoutsi Z, Fokialakis N, et al. Greek plant extracts exhibit selective estrogen receptor modulator (SERM)-like properties. J Agric Food Chem 2004;52:6956-61. PubMed
  9. Maliakal PP, Wanwimolruk S. Effect of herbal teas on hepatic drug metabolizing enzymes in rats. J Pharm Pharmacol 2001;53:1323-9. PubMed
  10. Segal R, Pilote L. Warfarin interaction with Matricaria chamomilla. CMAJ 2006;174:1281-2. PubMed
  11. Loggia RD, Traversa U, Scarcia V, et al. Depressive effects of Chamomilla recutita (L.) Rausch, tubular flowers, on central nervous system in mice. Pharmacol Res Commun 1982;14(2):153-162. PubMed
  12. Ganzera M, Schneider P, Stuppner H. Inhibitory effects of the essential oil of chamomile (Matricaria recutita L.) and its major constituents on human cytochrome P450 enzymes. Life Sci 2006;78(8):856-861. PubMed
  13. Benito P, Rodríguez-Perez R, García F, Juste S, Moneo I, Caballero ML. Occupational allergic rhinoconjunctivitis induced by Matricaria chamomilla with tolerance of chamomile tea. J Investig Allergol Clin Immunol. 2014;24(5):369-70. No abstract available.
  14. Braga FT, Santos AC, Bueno PC, et al. Use of Chamomilla recutita in the prevention and treatment of oral mucositis in patients undergoing hematopoietic stem cell transplantation: a randomized, controlled, phase II clinical trial. Cancer Nurs 2015;38(4):32 PubMed
  15. Sarris J, Ravindran A, Yatham LN, et al. Clinician guidelines for the treatment of psychiatric disorders with nutraceuticals and phytoceuticals: The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety T

See these in context on the German Chamomile monograph →

Valerian 37 references
  1. Willey LB, Mady SP, Cobaugh DJ, Wax PM. Valerian overdose: a case report. Vet Hum Toxicol 1995;37:364-5.
  2. Kuhlmann J, Berger W, Podzuweit H, Schmidt U. The influence of valerian treatment on "reaction time, alertness and concentration" in volunteers. Pharmacopsychiatry 1999;32:235-41. PubMed
  3. Klepser TB, Klepser ME. Unsafe and potentially safe herbal therapies. Am J Health Syst Pharm 1999;56:125-38. PubMed
  4. Houghton PJ. The scientific basis for the reputed activity of Valerian. J Pharm Pharmacol 1999;51:505-12. PubMed
  5. Garges HP, Varia I, Doraiswamy PM. Cardiac complications and delirium associated with Valerian root withdrawal. [Letter to the Editor]. JAMA 1998;280:1566-7. PubMed
  6. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  7. MacGregor FB, Abernethy VE, Dahabra S, et al. Hepatotoxicity of herbal remedies. BMJ 1989;299:1156-7. PubMed
  8. Leathwood PD, Chauffard F. Aqueous extract of valerian reduces latency to fall asleep in man. Planta Med 1985;2:144-8. PubMed
  9. Hadley S, Petry JJ. Valerian. Am Fam Physician 2003;67:1755-8..
  10. Glass JR, Sproule BA, Herrmann N, et al. Acute pharmacological effects of temazepam, diphenhydramine, and valerian in healthy elderly subjects. J Clin Psychopharmacol 2003;23:260-8. PubMed
  11. Lefebvre T, Foster BC, Drouin CE, et al. In vitro activity of commercial valerian root extracts against human cytochrome P450 3A4. J Pharm Pharmaceut Sci 2004;7:265-73.
  12. Yuan CS, Mehendale S, Xiao Y, et al. The gamma-aminobutyric acidergic effects of valerian and valerenic acid on rat brainstem neuronal activity. Anesth Analg 2004;98:353-8. PubMed
  13. Donovan JL, DeVane CL, Chavin KD, et al. Multiple night-time doses of valerian (Valeriana officinalis) had minimal effects on CYP3A4 activity and no effect on CYP2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:1333-6. PubMed
  14. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes. Clin Pharmacol Ther 2005;77:415-26. PubMed
  15. Gutierrez S, Ang-Lee MK, Walker DJ, Zacny JP. Assessing subjective and psychomotor effects of the herbal medication valerian in healthy volunteers. Pharmacol Biochem Behav 2004;78:57-64. PubMed
  16. Jacobs BP, Bent S, Tice JA, et al. An internet-based randomized, placebo-controlled trial of kava and valerian for anxiety and insomnia. Medicine (Baltimore) 2005;84:197-207. PubMed
  17. National Toxicology Program, US Department of Health and Human Services. Chemical Information Review Document for Valerian (Valeriana officinalis L.) [CAS No. 8057-49-6] and Oils [CAS No. 8008-88-6]. Supporting Nomination for Toxicological Evaluation by t
  18. Fernández-San-Martín MI, Masa-Font R, Palacios-Soler L, et al. Effectiveness of Valerian on insomnia: a meta-analysis of randomized placebo-controlled trials. Sleep Med. 2010 Jun;11:505-11. PubMed
  19. Coxeter PD, Schluter PJ, Eastwood HL, et al. Valerian does not appear to reduce symptoms for patients with chronic insomnia in general practice using a series of randomised n-of-1 trials. Complement Ther Med. 2003 Dec;11:215-22. PubMed
  20. Diaper A, Hindmarch I. A double-blind, placebo-controlled investigation of the effects of two doses of a valerian preparation on the sleep, cognitive and psychomotor function of sleep-disturbed older adults. Phytother Res. 2004 Oct;18:831-6. PubMed
  21. Cuellar NG, Ratcliffe SJ. Does valerian improve sleepiness and symptom severity in people with restless legs syndrome? Altern Ther Health Med 2009;15:22-8.
  22. Chen D, Klesmer J, Giovanniello A, et al. Mental status changes in an alcohol abuser taking valerian and gingko biloba. Am J Addict. 2002 Winter;11:75-7. PubMed
  23. Albrecht M, Berger W, Laux P, Schmidt U, et al. Psychopharmaka und Verkehrssicherheit. Der Einfluß von Euvegal® - Dragees forte auf die Fahrtüchtigkeit und Kombinationswirkungen mit Alkohol Z Allg Med 1995;71:1215-25.
  24. Carrasco MC, Vallejo JR, Pardo-de-Santayana M, et al. Interactions of Valeriana officinalis L. and Passiflora incarnata L. in a patient treated with lorazepam. Phytother Res. 2009 Dec;23:1795-6.
  25. Hellum BH, Nilsen OG. The in vitro inhibitory potential of trade herbal products on human CYP2D6-mediated metabolism and the influence of ethanol. Basic Clin Pharmacol Toxicol. 2007 Nov;101:350-8.
  26. Hellum BH, Hu Z, Nilsen OG. The induction of CYP1A2, CYP2D6 and CYP3A4 by six trade herbal products in cultured primary human hepatocytes. Basic Clin Pharmacol Toxicol. 2007 Jan;100:23-30. PubMed
  27. Alkharfy, K. M. and Frye, R. F. Effect of valerian, valerian/hops extracts, and valerenic acid on glucuronidation in vitro. Xenobiotica 2007;37(2):113-123.
  28. Vassiliadis, T., Anagnostis, P., Patsiaoura, K., Giouleme, O., Katsinelos, P., Mpoumponaris, A., and Eugenidis, N. Valeriana hepatotoxicity. Sleep Med 2009;10(8):935. PubMed
  29. Muller, Z., Sarkany, A., Altorjay, A., Szilagyi, A., Tura, T., and Ozsvar, Z. [Liver failure a la Eastern Europe]. Orv.Hetil. 3-22-2009;150(12):555-557. PubMed
  30. National Toxicology Program, US Department of Health and Human Services. Chemical Information Review Document for Valerian (Valeriana officinalis L.) [CAS No. 8057-49-6] and Oils [CAS No. 8008-88-6]. 2009;
  31. Wells SR. International intravenous administration of a crude valerian root extract. NACCT 1995;33:542.
  32. Aydinoglu U, Özcan H, Yücel A, Yücel N, Mutlu M. Valerian induced hypomania: a case report. Bull Clin Psychopharma 2012;22(Suppl. 1):S63.
  33. Mirabi P, Mojab F. The effects of valerian root on hot flashes in menopausal women. Iran J Pharm Res 2013;12(1):217-22.
  34. Thomas K, Canedo J, Perry PJ, et al. Effects of valerian on subjective sedation, field sobriety testing and driving simulator performance. Accid Anal Prev. 2016 Jul;92:240-4. PubMed
  35. Kia YH, Alexander S, Dowling D, Standish R. A case of steroid-responsive valerian-associated hepatitis. Intern Med J. 2016 Jan;46(1):118-9. PubMed
  36. Burke H, Jiang S, Chatham P, Stern TA. Delirium After Withdrawal From Valerian Root: A Case Report. Psychosomatics. 2020;61(6):787-790. PubMed
  37. Hajizadeh I, Jamshidi M, Kazemi M, Kargar H, Sadeghi T. Comparison the effect of valerian and gabapentin on RLS and sleep quality in hemodialysis patients: A randomized clinical trial. Ther Apher Dial 2023.

See these in context on the Valerian monograph →

Hops 15 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Zava DT, Dollbaum CM, Blen M. Estrogen and progestin bioactivity of foods, herbs, and spices. Proc Soc Exp Biol Med 1998;217:369-78. PubMed
  4. Milligan SR, Kalita JC, Heyerick A, et al. Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beer. J Clin Endocrinol Metab 1999;84:2249-52.. PubMed
  5. Milligan SR, Kalita JC, Pocock V, et al. The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoids. J Clin Endocrinol Metab 2000;85:4912-5.. DOI
  6. Henderson MC, Miranda CL, Stevens JF, et al. In vitro inhibition of human P450 enzymes by prenylated flavonoids from hops, Humulus lupulus. Xenobiotica 2000;30:235-51.. PubMed
  7. Mannering, G. J., Shoeman, J. A., and Deloria, L. B. Identification of the antibiotic hops component, colupulone, as an inducer of hepatic cytochrome P-4503A in the mouse. Drug Metab Dispos 1992;20(2):142-147. DOI
  8. Skorska, C., Mackiewicz, B., Gora, A., Golec, M., and Dutkiewicz, J. Health effects of inhalation exposure to organic dust in hops farmers. Ann.Univ Mariae.Curie Sklodowska [Med] 2003;58(1):459-465.
  9. Schiller, H., Forster, A., Vonhoff, C., Hegger, M., Biller, A., and Winterhoff, H. Sedating effects of Humulus lupulus L. extracts. Phytomedicine. 2006;13(8):535-541. PubMed
  10. van Hunsel, F. P. and Kampschoer, P. [Postmenopausal bleeding and dietary supplements: a possible causal relationship with hop- and soy-containing preparations]. Ned.Tijdschr.Geneeskd. 2012;156(41):A5095.
  11. Fenselau, C. and Talalay, P. Is oestrogenic activity present in hops? Food Cosmet.Toxicol. 1973;11(4):597-602. PubMed
  12. Godnic-Cvar, J., Zuskin, E., Mustajbegovic, J., Schachter, E. N., Kanceljak, B., Macan, J., Ilic, Z., and Ebling, Z. Respiratory and immunological findings in brewery workers. Am J Ind Med 1999;35(1):68-75. DOI
  13. Lee KM, Jung JS, Song DK, and et al. Effects of Humulus lupulus extract on the central nervous system in mice. Planta Med 1993;59(Suppl):A691.
  14. Assessment report on Humulus lupulus L., flos. European Medicines Agency, 2014. Available at: https://www.ema.europa.eu/en/documents/herbal-report/final-assessment-report-humulus-lupulus-l-flos_en.pdf. Accessed September 29, 2021.
  15. van Breemen RB, Chen L, Tonsing-Carter A, et al. Pharmacokinetic Interactions of a Hop Dietary Supplement with Drug Metabolism in Perimenopausal and Postmenopausal Women. J Agric Food Chem. 2020;68(18):5212-5220. PubMed

See these in context on the Hops monograph →

Kava 71 references
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Strahl S, Ehret V, Dahm HH, Maier KP. [Necrotizing hepatitis after taking herbal medication]. Dtsch Med Wochenschr 1998;123:1410-4.
  3. Spillane PK, et al. Neurological manifestations of kava intoxication. Med J Aust 1997;167:172-3. PubMed
  4. Swensen JN. Man convicted of driving under the influence of kava. Salt Lake City, UT: Deseret News, 1996.
  5. Pittler MH, Ernst E. Efficacy of kava extract for treating anxiety: systematic review and meta-analysis. J Clin Psychopharmacol 2000;20:84-9. PubMed
  6. Volz HP, Kieser M. Kava-kava extract WS 1490 versus placebo in anxiety disorders--a randomized placebo-controlled 25-week outpatient trial. Pharmacopsychiatry 1997;30:1-5. PubMed
  7. Heinze HJ, Munthe TF, Steitz J, Matzke M. Pharmacopsychological effects of oxazepam and kava-extract in a visual search paradigm assessed with event-related potentials. Pharmacopsychiatry 1994;27:224-30. PubMed
  8. Munte TF, Heinze HJ, Matzke M, Steitz J. Effects of oxazepam and an extract of kava roots (Piper methysticum) on event-related potentials in a word recognition task. Neuropsychobiology 1993;27:46-53.
  9. Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed
  10. Schelosky L, Raffaup C, Jendroska K, Poewe W. Kava and dopamine antagonism. J Neurol Neurosurg Psychiatry 1995;58:639-40. PubMed
  11. Norton SA, Ruze P. Kava dermopathy. J Am Acad Dermatol 1994;31:89-97.
  12. Pizzorno JE, Murray MT, eds. Textbook of Natural Medicine. 2nd ed. Edinburgh:Churchill Livingstone, 1999.
  13. Mathews JD, Riley MD, Fejo L, et al. Effects of heavy usage of kava on physical health: Summary of a pilot survey in an aboriginal community. Med J Aust 1988;148:548-55.
  14. Escher M, Desmeules J, Giostra E, Mentha G. Hepatitis associated with Kava, a herbal remedy for anxiety. BMJ 2001;322:139.
  15. Russmann S, Lauterburg BH, Helbling A. Kava hepatotoxicity [letter]. Ann Intern Med 2001;135:68-9.
  16. Liver Toxicity With Kava. Pharmacist's Letter/Prescriber's Letter. January 2001.
  17. Consultation letter MLX 286: Proposals to prohibit the herbal ingredient Kava-Kava (Piper methysticum) in unlicensed medicines. Medicines Control Agency, United Kingdom, July 19, 2002.
  18. Meseguer E, Taboada R, Sanchez V, et al. Life-threatening parkinsonism induced by kava-kava. Mov Disord 2002;17:195-6. PubMed
  19. Ruze P. Kava-induced dermopathy: a niacin deficiency? Lancet 1990;335:1442-5. PubMed
  20. Singh YN. Kava: an overview. J Ethnopharmacol 1992;37:13-45.
  21. Bilia AR, Gallori S, Vincieri FF. Kava-kava and anxiety: growing knowledge about the efficacy and safety. Life Sci 2002;70:2581-97. PubMed
  22. Wooltorton E. Herbal kava: reports of liver toxicity. CMAJ 2002;166:777.
  23. Mathews JM, Etheridge AS, Black SR. Inhibition of human cytochrome P450 activities by kava extract and kavalactones. Drug Metab Dispos 2002;30:1153-7. PubMed
  24. Logan JL, Ahmed J. Critical hypokalemic renal tubular acidosis due to Sjogren's syndrome: association with the purported immune stimulant echinacea. Clin Rheumatol 2003;22:158-9.
  25. Teschke R, Gaus W, Loew D. Kava extracts: safety and risks including rare hepatotoxicity. Phytomedicine 2003;10:440-6. PubMed
  26. Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.
  27. Schulze J, Raasch W, Siegers CP. Toxicity of kava pyrones, drug safety and precautions--a case study. Phytomedicine 2003;10:68-73.. PubMed
  28. Pittler MH, Ernst E. Kava extract for treating anxiety. Cochrane Database Syst Rev 2003;(1):CD003383.
  29. Cairney S, Maruff P, Clough AR, et al. Saccade and cognitive impairment associated with kava intoxication. Hum Psychopharmacol 2003;18:525-33. PubMed
  30. Moulds RF, Malani J. Kava: herbal panacea or liver poison? Med J Aust 2003;178:451-3. PubMed
  31. Gow PJ, Connelly NJ, Hill RL, et al. Fatal fulminant hepatic failure induced by a natural therapy containing kava. Med J Aust 2003;178:442-3. PubMed
  32. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  33. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes. Clin Pharmacol Ther 2005;77:415-26. PubMed
  34. Weiss J, Sauer A, Frank A, Unger M. Extracts and kavalactones of Piper methysticum G. Forst (kava-kava) inhibit P-glycoprotein in vitro. Drug Metab Dispos 2005;33:1580-3. PubMed
  35. Gurley BJ, Swain A, Barone GW, et al. Effect of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on digoxin pharmacokinetics in humans. Drug Metab Dispos 2007;35:240-5. PubMed
  36. Gurley BJ, Swain A, Hubbard MA, et al. Clinical assessement of CYP2D6-mediated herb-drug interactions in humans: Effects of milk-thistle, black cohosh, goldenseal, kava kava, St. John's wort, and Echinacea. Mol Nutr Food Res 2008;52:755-63.
  37. Li XZ, Ramzan I. Role of ethanol in kava hepatotoxicity. Phytother Res 2010;24:475-80. PubMed
  38. Bodkin R, Schneider S, Rekkerth D, et al. Rhabdomyolysis associated with kava ingestion. Am J Emerg Med 2012;30:635.el-3. PubMed
  39. Donadio V, Bonsi P, Zele I, et al. Myoglobinuria after ingestion of extracts of guarana, Ginkgo biloba and kava. Ginkgo biloba and kava. Neurol Sci 2000;21:124. PubMed
  40. Sarris J, Kavanagh DJ, Byrne G, et al. The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum. Psychopharmacology 2009;205:399-407. PubMed
  41. Hannam S, Murray M, Romani L, Tuicakau M, J Whitfeld M. Kava dermopathy in Fiji: an acquired ichthyosis? Int J Dermatol 2014;53(12):1490-4. PubMed
  42. Huynh JC, Asgari MM, Moore MM. Sebotropic eruption associated with use of oral kava kava supplement. Clin Exp Dermatol 2014;39(7):816-8. PubMed
  43. Teschke R, Sarris J, Schweitzer I. Kava hepatotoxicity in traditional and modern use: the presumed Pacific kava paradox hypothesis revisited. Br J Clin Pharmacol 2012;73(2):170-4. PubMed
  44. Scherer, J. Kava-kava extract in anxiety disorders: an outpatient observational study. Adv.Ther. 1998;15(4):261-269.
  45. Humberston, C. L., Akhtar, J., and Krenzelok, E. P. Acute hepatitis induced by kava kava. J Toxicol.Clin Toxicol. 2003;41(2):109-113. PubMed
  46. Schmidt, M. Are kavalactones the hepatotoxic principle of kava extracts? The pitfalls of the glutathione theory. J Altern Complement Med 2003;9(2):183-187. PubMed
  47. Stickel, F., Baumuller, H. M., Seitz, K., Vasilakis, D., Seitz, G., Seitz, H. K., and Schuppan, D. Hepatitis induced by Kava (Piper methysticum rhizoma). J Hepatol. 2003;39(1):62-67. PubMed
  48. Grace, R. Kava-induced urticaria. J Am Acad Dermatol 2005;53(5):906. PubMed
  49. Christl, S. U., Seifert, A., and Seeler, D. Toxic hepatitis after consumption of traditional kava preparation. J.Travel.Med. 2009;16(1):55-56. PubMed
  50. Teschke, R., Genthner, A., and Wolff, A. Kava hepatotoxicity: comparison of aqueous, ethanolic, acetonic kava extracts and kava-herbs mixtures. J.Ethnopharmacol. 6-25-2009;123(3):378-384. PubMed
  51. Jappe, U., Franke, I., Reinhold, D., and Gollnick, H. P. Sebotropic drug reaction resulting from kava-kava extract therapy: a new entity? J Am Acad Dermatol. 1998;38(1):104-106. PubMed
  52. Gessner B and Cnota P. Extract of the kava-kava rhizome in comparison with diazepam and placebo. Z Phytother 1994;15(1):30-37.
  53. Johnson D, Frauendorf A, Stecker K, and et al. Neurophysiological active profile and tolerance of kava extract WS 1490, A pilot study with randomized evaluation. TW Neurolgie Psychiatrie 1991;5(6):349-354.
  54. Keller F and Klohs M. A review of the chemistry and pharmacology of the constituents of Piper methysticum. Lloydia 1963;26:1-15.
  55. Siegers CP, Honold E, Krall B, and et al. Results of the drug monitoring L 1090 with Laitan capsules. Arztl Forsch 1992;39:7-11.
  56. Chanwai, L. G. Kava toxicity. Emergency Medicine 2002;12:142-145.
  57. Leung, N. Acute urinary retention secondary to kava ingestion. Emerg Med Australas 2004;16(1):94. PubMed
  58. Teschke R. Kava hepatotoxicity: pathogenetic aspects and prospective considerations. Liver Int 2010;30(9):1270-9. PubMed
  59. Toohey TP, Lu BY, Wada C. Toxic effects of psychotropics related to possible p450 enzyme inhibition by kava:report of 2 cases. Prim Care Companion CNS Disord 2013;15(5). PubMed
  60. Ostermayer D. News: Kava, Popular as Alcohol Alternative, May Cause Toxicity. Emerg Med News. 2016;38(1B).
  61. Kuchta K, Schmidt M, Nahrstedt A. German Kava Ban Lifted by Court: The Alleged Hepatotoxicity of Kava (Piper methysticum) as a Case of Ill-Defined Herbal Drug Identity, Lacking Quality Control, and Misguided Regulatory Politics. Planta Med. 2015;81(18):16 PubMed
  62. Schmidt M. German Court Ruling Reverses Kava Ban; German Regulatory Authority Appeals Decision. HerbalEGram. 2014;11(7).
  63. Wainiqolo I, Kool B, Nosa V, Ameratunga S. Is driving under the influence of kava associated with motor vehicle crashes? A systematic review of the epidemiological literature. Aust N Z J Public Health 2015;39(5):495-9. PubMed
  64. Wainiqolo I, Kafoa B, Kool B, et al. Driving following kava use and road traffic injuries: a population-based case-control study in Fiji (TRIP 14). PLoS One 2016;11(3):e0149719. PubMed
  65. Asher GN, Corbett AH, Hawke RL. Common Herbal Dietary Supplement-Drug Interactions. Am Fam Physician. 2017;96(2):101-107.
  66. Sarris J, Byrne GJ, Bousman CA, et al. Kava for generalised anxiety disorder: A 16-week double-blind, randomised, placebo-controlled study. Aust N Z J Psychiatry. 2020 Mar;54(3):288-297. PubMed
  67. Aporosa AS, Atkins M, Brunton R. Kava drinking in traditional settings: towards understanding effects on cognitive function. Hum Psychopharmacol. 2020;35(2):e2725. PubMed
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See these in context on the Kava monograph →

Passion Flower 19 references
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  2. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
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See these in context on the Passion Flower monograph →

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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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