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

Pau d'Arco Complex Ingredients & Drug Interactions

by Allergy Research Group

Pau d'Arco Complex label
See full label image
Capsule Category: Botanical With Nutrients
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Pau d'Arco Complex 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

Pau d'Arco Complex is a dietary supplement by Allergy Research Group with 6 active ingredients. Its ingredients are commonly taken for hair growth and thinning hair, brittle nails, skin health.Based on those ingredients, 542 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Magnesium, Caprylic Acid, Oregano oil powder. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Pau d'Arco Complex by Allergy Research Group

Ask about any prescription or over-the-counter medication and we check it for interactions with Pau d'Arco Complex by Allergy Research Group — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Pau d'Arco Complex by Allergy Research Group

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 Sep 3, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 6 of its 6 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Pau d'Arco Complex contains 6 active ingredients. Biotin is a B vitamin needed for hair, skin, and nail health.

Caprylic acid is a medium-chain fatty acid derived from coconut oil. Black Walnut is a plant traditionally used in herbal practice.

Magnesium is an essential mineral that plays a role in nerve and muscle function and energy production. Oregano oil powder is a concentrated extract of the common culinary herb.

Pau d'Arco is bark extract from a South American tree, also known as lapacho or tabebuia. The product also contains inactive ingredients—hydroxypropyl methylcellulose, garlic, cat's claw, silica, magnesium stearate, and microcrystalline cellulose—which serve as capsule material, binders, and fillers.

Does it work?

Insufficient 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
Insufficient

There isn't enough reliable clinical evidence to rate this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: support healthy balance of intestinal bacteria.
  • We looked for evidence on: Intestinal parasite infection, Dysbiosis, Candida overgrowth, Gut microbiome imbalance.
  • The closest evidence on file: Oregano is rated "Insufficient Reliable Evidence To Rate" for Intestinal parasite infection (Natural Medicines).

The evidence for this product's ingredients is mixed. Biotin is likely effective for biotin deficiency but is possibly ineffective for multiple sclerosis and seborrheic dermatitis; evidence is insufficient to rate it for alopecia areata.

Magnesium is effective for dyspepsia, constipation, and magnesium deficiency, and effective in pregnancy for preventing pre-eclampsia. The effectiveness of caprylic acid, black walnut, oregano oil powder, and pau d'Arco for their proposed uses is not established—the data we hold shows insufficient evidence to rate them for conditions like epilepsy, essential tremor, coronary heart disease, wound healing, acne, bronchitis, asthma, cancer, peptic ulcers, and dysmenorrhea.

The evidence, ingredient by ingredient Biotin Caprylic Acid Black Walnut Magnesium Oregano Pau D'arco

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 6 of the 6 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 6 of 6.
  • General safety write-ups exist for 6 of 6.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Biotin is generally well tolerated, even at fairly high doses, and is likely safe in pregnancy and lactation; however, high-dose supplements should be discussed with your doctor first. Caprylic acid is generally recognized as safe in food amounts, but supplement doses are less well studied—supplement use should be approved by your doctor.

Black Walnut has limited human safety data; the facts advise avoiding it in pregnancy and while breastfeeding, though it is listed as likely safe in pregnancy (a conflict in the source data). Magnesium is generally well tolerated at recommended amounts; common side effects with oral use are diarrhea, gastrointestinal irritation, nausea, and vomiting.

It is likely safe in pregnancy but should be used only under your doctor's guidance; use in lactation is possibly safe but should be discussed with your doctor. Oregano oil powder is well tolerated in food amounts, but concentrated supplements are stronger and less studied; avoid medicinal amounts in pregnancy and stick to food amounts while breastfeeding.

Pau d'Arco has limited human safety data; the facts advise avoiding it in pregnancy and while breastfeeding due to possible harm. Both oregano and pau d'Arco carry a rare risk of serious allergic reaction, including anaphylaxis.

Side effects, ingredient by ingredient Biotin Caprylic Acid Black Walnut Magnesium Oregano Pau D'arco

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?
  • 4 of the 6 matched ingredients can interact with medications — Oregano, Pau D'arco, Magnesium, Caprylic Acid.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; heart-rhythm medications; Parkinson's medications.
  • For scale: 542 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 taking this product, check with your own doctor or pharmacist if you take levodopa/carbidopa (Parkinson's disease)—magnesium can significantly reduce its effectiveness. Also double-check if you take anticoagulants or antiplatelet drugs like warfarin or aspirin, as oregano oil powder and pau d'Arco carry a Moderate-severity bleeding risk.

If you use NSAIDs regularly, take quinolone antibiotics or bisphosphonates, use diabetes medications, take calcium channel blockers or skeletal muscle relaxants, use potassium-sparing diuretics, or take acid reducers, discuss this product with your doctor or pharmacist, as magnesium and caprylic acid may affect how these drugs work.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with insufficient evidence for its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

This product is a multi-ingredient herbal and nutrient blend with several documented interactions, most notably magnesium's effect on Parkinson's medications and the bleeding risk with blood thinners from oregano and pau d'Arco. If you take any prescription medications—especially Parkinson's drugs, blood thinners, diabetes medications, antibiotics, osteoporosis drugs, or heart medications—check this product against your full medication list before starting.

Talk with your own doctor or pharmacist to decide whether it's right for you.

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

Assessment coverage: 6 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2020.

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 Pau d'Arco Complex, straight from the product label.

Brand Allergy Research Group
Barcode (UPC) 713947775503
Net contents 90 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 233265
Product type Botanical With Nutrients
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 Pau d'Arco Complex by Allergy Research Group, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
45
UPC/BARCODE
713947775503
IngredientAmount% DV
Calories10 Calorie(s)--
Total Carbohydrates1 Gram(s)1%
Calories from Fat5 Calorie(s)--
Trans Fat0.5 Gram(s)--
Total Fat0 NP1%
Biotin2000 mcg667%
Saturated Fat0.5 Gram(s)3%
Caprylic Acid500 mg--
Black Walnut300 mg--
Magnesium45 mg11%
Oregano oil powder200 mg--
Pau d'Arco300 mg--

Other ingredients: Hydroxypropyl Methylcellulose, Garlic, Cat's Claw, Silica, Magnesium Stearate, Microcrystalline Cellulose

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.
Formula

Provides ingredients that may help to support a healthy balance of intestinal bacteria. These include Pau d'Arco, Black Walnut, Oregano Oil, Biotin, and Caprylic Acid.

Suggested/Recommended/Usage/Directions

Suggested Use As a dietary supplement, 2 capsules one or two times daily with food, or as directed by a healthcare professional.

Precautions

Caution: If pregnant or nursing, use only under the supervision of a qualified healthcare practitioner.

Keep out of reach of children.

Contains: Tree Nut (walnut hulls).

Warning: Consuming this product can expose you to lead which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov/food

Formulation

Variations in product color may occur.

Candida Support Formula

Storage

Keep in a cool, dry place, tightly capped.

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

FDA Statement of Identity

Dietary Supplement

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

See for yourself

Pau d'Arco Complex by Allergy Research Group label

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

Pau d'Arco Complex 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 Pau d'Arco Complex by Allergy Research Group

These are the 6 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container45 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.

Biotin

No known
interactions
2000 mcg per serving

Biotin (vitamin B7) is a water-soluble vitamin your body needs to turn food into energy and to support healthy hair, skin, and nails. Most people get...

Biotin monograph & interactions

Caprylic Acid

Interacts with
262 drugs
500 mg per serving Form: Magnesium Caprylate

Caprylic acid is a medium-chain fatty acid found in coconut oil and palm kernel oil that is popularly used for yeast overgrowth and gut health. While...

Caprylic Acid monograph & interactions

Black Walnut

No known
interactions
300 mg per serving

Black walnut is a tree whose green hulls are traditionally used as a natural antiparasitic and digestive remedy, but solid human evidence for these us...

Black Walnut monograph & interactions

Magnesium

Interacts with
295 drugs
45 mg per serving Form: Magnesium Caprylate

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preven...

Magnesium monograph & interactions

Oregano oil powder

Interacts with
208 drugs
200 mg per serving

Oregano is a common Mediterranean cooking herb that is also sold as a concentrated oil or supplement, often standardized for a compound called carvacr...

Oregano oil powder monograph & interactions

Pau d'Arco

Interacts with
122 drugs
300 mg per serving

Pau d'arco is a South American tree bark traditionally used for infections and inflammation, and it contains compounds like lapachol that show activit...

Pau d'Arco monograph & interactions

Other (inactive) ingredients: Hydroxypropyl Methylcellulose, Garlic, Cat's Claw, Silica, Magnesium Stearate, Microcrystalline Cellulose. These complete the product’s ingredient list but are not active constituents.

Interaction report

Pau d'Arco Complex by Allergy Research Group Drug Interactions

Want to check YOUR meds against Pau d'Arco Complex?

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
542Drugs
6 Major 534 Moderate 2 Minor

Ingredients driving the most interactions

Magnesium 295
Caprylic Acid 262
Oregano oil powder 208
Pau d'Arco 122

Individual Drug Interactions

The ingredients in Pau d'Arco Complex interact with 542 drugs. Click any drug to see the details.

4 of the 6 ingredients in Pau d'Arco Complex interact with drugs. Each result below shows which ingredient is responsible. Magnesium Caprylic Acid Oregano oil powder Pau d'Arco

Each ingredient & the kinds of drugs it affects

For each ingredient in Pau d'Arco Complex 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.

Magnesium15 drug types · 295 drugs

Levodopa/Carbidopa (Sinemet)

Magnesium can reduce the bioavailability of levodopa/carbidopa.
Clinical research in healthy volunteers shows that taking magnesium oxide 1000 mg with levodopa 100 mg/carbidopa 10 mg reduces the area under the curve (AUC) of levodopa by 35% and of carbidopa by 81%. In vitro and animal research shows that magnesium produces an alkaline environment in the digestive tract, which might lead to degradation and reduced bioavailability of levodopa/carbidopa.

Likelihood Probable Evidence B
Aminoglycoside Antibiotics

Concomitant use of aminoglycoside antibiotics and magnesium can increase the risk for neuromuscular weakness.
Both aminoglycosides and magnesium reduce presynaptic acetylcholine release, which can lead to neuromuscular blockade and possible paralysis. This is most likely to occur with high doses of magnesium given intravenously.

Likelihood Possible Evidence D
Antacids

Use of acid reducers may reduce the laxative effect of magnesium oxide.
A retrospective analysis shows that, in the presence of H2 receptor antagonists (H2RAs) or proton pump inhibitors (PPIs), a higher dose of magnesium oxide is needed for a laxative effect. This may also occur with antacids. Under acidic conditions, magnesium oxide is converted to magnesium chloride and then to magnesium bicarbonate, which has an osmotic laxative effect. By reducing acidity, antacids may reduce the conversion of magnesium oxide to the active bicarbonate salt.

Likelihood Possible Evidence D
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Magnesium might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after magnesium containing products.

Likelihood Probable Evidence D
Bisphosphonates

Magnesium can decrease absorption of bisphosphonates.
Cations, including magnesium, can decrease bisphosphonate absorption. Advise patients to separate doses of magnesium and these drugs by at least 2 hours.

Likelihood Probable Evidence B
Calcium Channel Blockers

Magnesium can have additive effects with calcium channel blockers, although evidence is conflicting.
Magnesium inhibits calcium entry into smooth muscle cells and may therefore have additive effects with calcium channel blockers. Severe hypotension and neuromuscular blockades may occur when nifedipine is used with intravenous magnesium, although some contradictory evidence suggests that concurrent use of magnesium with nifedipine does not increase the risk of neuromuscular weakness. High doses of magnesium could theoretically have additive effects with other calcium channel blockers.

Likelihood Possible Evidence D
Digoxin

Magnesium salts may reduce absorption of digoxin.
Clinical evidence suggests that treatment with oral magnesium hydroxide or magnesium trisilicate reduces absorption of digoxin from the intestines. This may reduce the blood levels of digoxin and decrease its therapeutic effects.

Likelihood Possible Evidence B
Potassium-Sparing Diuretics

Potassium-sparing diuretics decrease excretion of magnesium, possibly increasing magnesium levels.
Potassium-sparing diuretics also have magnesium-sparing properties, which can counteract the magnesium losses associated with loop and thiazide diuretics. Theoretically, increased magnesium levels could result from concomitant use of potassium-sparing diuretics and magnesium supplements.

Likelihood Probable Evidence D
Quinolone Antibiotics

Magnesium decreases absorption of quinolones.
Magnesium can form insoluble complexes with quinolones and decrease their absorption. Advise patients to take these drugs at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

Likelihood Probable Evidence D
Skeletal Muscle Relaxants

Parenteral magnesium alters the pharmacokinetics of skeletal muscle relaxants, increasing their effects and accelerating the onset of effect.
Parenteral magnesium shortens the time to onset of skeletal muscle relaxants by about 1 minute and prolongs the duration of action by about 2 minutes. Magnesium potentiates the effects of skeletal muscle relaxants by decreasing calcium-mediated release of acetylcholine from presynaptic nerve terminals, reducing postsynaptic sensitivity to acetylcholine, and having a direct effect on the membrane potential of myocytes. Magnesium also has vasodilatory actions and increases cardiac output, allowing a greater amount of muscle relaxant to reach the motor end plate. A clinical study found that low-dose rocuronium (0.45 mg/kg), when given after administration of magnesium 30 mg/kg over 10 minutes, has an accelerated onset of effect, which matches the onset of effect seen with a full-dose rocuronium regimen (0.6 mg/kg). In another clinical study, onset times for rocuronium doses of 0.3, 0.6, and 1.2 mg/kg were 86, 76, and 50 seconds, respectively, when given alone, but were reduced to 66, 44, and 38 seconds, respectively, when the doses were given after a 15-minute infusion of magnesium sulfate 60 mg/kg. Giving intraoperative intravenous magnesium sulfate, 50 mg/kg loading dose followed by 15 mg/kg/hour, reduces the onset time of rocuronium, enhances its clinical effects, reduces the dose of intraoperative opiates, and prolongs the spontaneous recovery time. It does not affect the activity of subsequently administered neostigmine.

Likelihood Probable Evidence A
Sulfonylureas

Magnesium increases the systemic absorption of sulfonylureas, increasing their effects and side effects.
Clinical research shows that administration of magnesium hydroxide with glyburide increases glyburide absorption, increases maximal insulin response by 35-fold, and increases the risk of hypoglycemia, when compared with glyburide alone. A similar interaction occurs between magnesium hydroxide and glipizide. The mechanism of this effect appears to be related to the elevation of gastrointestinal pH by magnesium-based antacids, increasing solubility and enhancing absorption of sulfonylureas.

Likelihood Probable Evidence B
Tetracycline Antibiotics

Magnesium decreases absorption of tetracyclines.
Magnesium can form insoluble complexes with tetracyclines in the gut and decrease their absorption and antibacterial activity. Advise patients to take these drugs 1 hour before or 2 hours after magnesium supplements.

Likelihood Probable Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, magnesium may have antiplatelet effects, but the evidence is conflicting.
In vitro evidence shows that magnesium sulfate inhibits platelet aggregation, even at low concentrations. Some preliminary clinical evidence shows that infusion of magnesium sulfate increases bleeding time by 48% and reduces platelet activity. However, other clinical research shows that magnesium does not affect platelet aggregation, although inhibition of platelet-dependent thrombosis can occur.

Likelihood Unlikely Evidence B
Gabapentin (Neurontin)

Gabapentin absorption can be decreased by magnesium.
Clinical research shows that giving magnesium oxide orally along with gabapentin decreases the maximum plasma concentration of gabapentin by 33%, time to maximum concentration by 36%, and area under the curve by 43%. Advise patients to take gabapentin at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

Likelihood Unlikely Evidence B
Sevelamer (Renagel, Renvela)

Sevelamer may increase serum magnesium levels.
In patients on hemodialysis, sevelamer use was associated with a 0.28 mg/dL increase in serum magnesium. The mechanism of this interaction remains unclear.

Likelihood Possible Evidence B
Magnesium full monograph & interactions

Caprylic Acid3 drug types · 262 drugs

Antihypertensive Drugs

Theoretically, caprylic acid might increase the risk of hypotension when used with antihypertensive drugs.
Animal research suggests that caprylic acid might have positive inotropic effects, resulting in reduced arterial pressure and vascular resistance and increased cardiac output.

Likelihood Possible Evidence D
Nonsteroidal Anti-Inflammatory Drugs (Nsaids)

Theoretically, caprylic acid might increase plasma concentrations of NSAIDs.
In vitro research suggests that caprylic acid might displace NSAIDs from binding sites on albumin. This effect has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, caprylic acid might increase plasma concentrations of warfarin.
In vitro research suggests that high doses of caprylic acid might displace warfarin from albumin binding sites. This effect has not been reported in humans.

Likelihood Possible Evidence D
Caprylic Acid full monograph & interactions

Oregano oil powder2 drug types · 208 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, oregano might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro research shows that aristolochic acid isolated from oregano leaves has antithrombin activity. It has also been reported that oregano oil inhibits arachidonic acid-induced, and ADP-induced, platelet aggregation.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, oregano might increase the risk for hypoglycemia when taken with antidiabetes drugs.
In vitro and animal research shows that oregano extracts might lower blood glucose levels.

Likelihood Possible Evidence D
Oregano oil powder full monograph & interactions

Pau d'Arco1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, pau d'arco might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro research shows that pau d'arco reduces platelet aggregation and may interfere with vitamin K. One clinical study shows that taking the lapachol constituent of pau d'arco in doses above 1.5 grams daily increases the risk of bleeding. The effects of whole pau d'arco or pau d'arco extract in humans are unclear.

Likelihood Possible Evidence D
Pau d'Arco full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Pau d'Arco Complex, from the product label.

Allergy Research Group

See all Allergy Research Group products
Name
Allergy Research Group
City
South Salt Lake
State
UT
ZipCode
84115
Phone Number
800-545-9960
Web Address
www.allergyresearchgroup.com
Pharmacist Counseling Corner

Pau d'Arco Complex by Allergy Research Group: Common Questions

Does Pau d'Arco Complex by Allergy Research Group interact with any medications?
Yes. Based on its ingredients, Pau d'Arco Complex has a known interaction with 542 medications, including 6 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Pau d'Arco Complex contains 6 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.
Is it safe to take this during pregnancy?
Black Walnut, oregano oil powder, and pau d'Arco are listed as possibly unsafe in pregnancy and should be avoided. Biotin is likely safe, and magnesium is likely safe but should be used only under your doctor's guidance. Talk with your doctor or pharmacist before starting this product if you are pregnant.
Is it safe while breastfeeding?
Black Walnut and pau d'Arco should be avoided while breastfeeding. Biotin is likely safe. Magnesium is possibly safe but should be discussed with your doctor first. Oregano oil powder should be limited to food amounts; concentrated supplement safety is not established. Check with your doctor or pharmacist before use.
What is pau d'Arco used for?
Pau d'Arco is traditionally used for cancer, peptic ulcers, wound healing, and dysmenorrhea, but the evidence to support these uses is insufficient. There is not enough reliable data to know whether it works for these purposes.
Can this product cause side effects?
Yes. Magnesium commonly causes diarrhea, nausea, and gastrointestinal irritation. Caprylic acid may cause mild abdominal discomfort, dizziness, headache, or fatigue. Black Walnut leaf, bark, and hull may cause gastrointestinal upset. Oregano and pau d'Arco can rarely cause serious allergic reactions.
Does biotin really help with hair and nails?
Biotin is likely effective for biotin deficiency, which can affect hair, skin, and nails. However, it is possibly ineffective for alopecia areata (hair loss), and evidence is insufficient to rate it for other conditions affecting these areas.
Does this product contain fillers or binders?
Yes, the product contains inactive ingredients including hydroxypropyl methylcellulose (capsule material), microcrystalline cellulose (filler), magnesium stearate (binder), silica, garlic, and cat's claw.

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.

Pau d'Arco Complex label
Go deeper

The Full Monographs Behind Pau d'Arco Complex’s Ingredients

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

Herb & supplement monograph

Biotin

Biotin (vitamin B7) is a water-soluble vitamin your body needs to turn food into energy and to support healthy hair, skin, and nails. Most people get plenty from a normal diet, and true defi...

Read the full Biotin monograph → Herb & supplement monograph

Caprylic Acid

Interacts with 262 drugs

Caprylic acid is a medium-chain fatty acid found in coconut oil and palm kernel oil that is popularly used for yeast overgrowth and gut health. While laboratory studies show it has antimicro...

Read the full Caprylic Acid monograph → Herb & supplement monograph

Black Walnut

Black walnut is a tree whose green hulls are traditionally used as a natural antiparasitic and digestive remedy, but solid human evidence for these uses is lacking. It contains a compound ca...

Read the full Black Walnut monograph → Herb & supplement monograph

Magnesium

Interacts with 295 drugs

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preventing or correcting deficiency. Some othe...

Read the full Magnesium monograph → Herb & supplement monograph

Oregano

Interacts with 208 drugs

Oregano is a common Mediterranean cooking herb that is also sold as a concentrated oil or supplement, often standardized for a compound called carvacrol. While lab studies suggest it may hav...

Read the full Oregano monograph → Herb & supplement monograph

Pau D'arco

Interacts with 122 drugs

Pau d'arco is a South American tree bark traditionally used for infections and inflammation, and it contains compounds like lapachol that show activity in lab studies. However, strong human...

Read the full Pau D'arco monograph →
Sources

Sources & How We Checked

Pau d'Arco Complex'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 112 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.

Biotin 4 references
  1. Debourdeau PM, Djezzar S, Estival JL, et al. Life-threatening eosinophilic pleuropericardial effusion related to vitamins B5 and H. Ann Pharmacother 2001;35:424-6. DOI
  2. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  3. Mock DM, Quirk JG, Mock NI. Marginal biotin deficiency during normal pregnancy. Am J Clin Nutr 2002;75:295-9. PubMed
  4. Sedel F, Papeix C, Bellanger A, Touitou V, Lebrun-Frenay C, Galanaud D, et al. High doses of biotin in chronic progressive multiple sclerosis: a pilot study.Mult Scler Relat Disord. 2015;4(2):159-69. doi: 10.1016/j.msard.2015.01.005. PubMed

See these in context on the Biotin monograph →

Caprylic Acid 5 references
  1. Massolini G, Aubry AF, McGann A, Wainer IW. Determination of the magnitude and enantioselectivity of ligand binding to rat and rabbit serum albumins using immobilized-protein high performance liquid chromatography stationary phases. Biochem Pharmacol 1993 PubMed
  2. Kristev A, Mitkov D, Lukanov Y, Chapkynov P. The effect of octanoic fatty acid on the cardiovascular system of the guinea pig. Cor Vasa 1989;31(4):321-7.
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Black Walnut 3 references
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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.

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