Pau d’arco is derived from tree bark of the Tabebuia impetiginosa or Tabebuia avellanedae species. It contains plant-based naphthoquinone compounds called lapachol and beta-lapachone. Vitamin K is also a naphthoquinone and increases blood clotting. This may explain why pau d’arco may sometimes cause the side effect of impaired blood clotting.
These plant-based compounds, drawn from the rainforests of Central and South America, are studied for their potential antibacterial, antiviral, and antifungal effects. Used in herbal medicine for centuries and available as a dietary supplement, pau d’arco also includes a potent antioxidant known as quercetin. Research has been done on the individual components of pau d’arco and the whole plant. When a whole plant is used, there is sometimes a synergistic effect. That means the whole plant might work better than just one of its chemical components alone.
This article looks at the current research on pau d’arco. This research includes preliminary studies that could lead to treatment for those living with inflammatory illnesses (like arthritis) and infections caused by a yeast called Candida. This article also lists commonly used dosages and possible side effects and risks associated with this herbal remedy.
Uses of Pau D’Arco
In folk medicine, pau d’arco has been used to treat a wide range of medical disorders, including anemia, asthma, bronchitis, diabetes, eczema, enlarged prostate, influenza, intestinal worms, sexually transmitted infections, skin infections, urinary tract infections, and cancer. There is generally not good quality evidence supporting any of these uses.
Everything You Need to Know About Pau D’Arco
Dietary supplements are not regulated like drugs in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement that has been tested by a trusted third party, such as USP, ConsumerLabs, or NSF. However, even if supplements are third-party tested, that doesn’t mean they are necessarily safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and to check inabout any potential interactions with other supplements or medications.
Supplement Facts
Active ingredients: Beta-lapachone, lapachol, quercetin.
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.
There is some preliminary evidence from research in animals, animal cells, and human cells that pau d’arco could one day help treat medical conditions. Research done in cells is called in vitro research. This phrase lets you know that pau d’arco has not been studied enough in humans to conclude yet.
Here is a look at some of the critical research findings.
Inflammation
Pau d’arco has been studied in several types of inflammation, including Pau d’arco (Tabebuia avellanedae) extract decreasing inflammatory cyclooxygenase II (COX-2) in human cells.
Researchers studied Pau d’arco (Tabebuia avellanedae) water extract in mouse cells and live mice. The mouse cell study showed decreased production of some inflammatory chemicals, including prostaglandins, nitric oxide, and COX-2. These results suggest possible anti-inflammatory effects of pau d’arco. In the live mouse study, researchers gave the animals a substance called arachidonic acid to cause ear swelling. They found that Tabebuia avellanedae extract given to the mice by mouth decreased the swelling.
More about prostaglandins: Prostaglandins are produced at tissue damage or infection sites. They cause inflammation, pain, and fever as part of the healing process. By countering this effect, pau d’arco may reverse swelling and pain associated with inflammatory conditions such as osteoarthritis, rheumatoid arthritis, and benign prostatic hyperplasia (enlarged prostate). These effects are still theoretical, and more study in people is needed before researchers can draw firm conclusions.
Another study also used Tabebuia avellanedae water extract in mice with colitis to test anti-inflammatory effects. Scientists found that the extract caused mice to have fewer clinical symptoms and reduced tissue inflammation. Like the previous study, results from mouse studies may be somewhat promising but cannot necessarily be applied to humans.
Infections
The Tabebuia tree bark is highly resistant to rotting, mold, and other common tree pathogens (bacteria, viruses, or other tiny organisms that may cause disease). These properties may or may not eventually translate to the treatment or prevention of common bacterial, viral, or fungal infections in people. This section includes one study in humans that used a combination product, but most research has been done in animals and in vitro.
Fungal infections
Scientists conducted a small study in 60 people with vaginal yeast infections caused by Candida. The people were treated with a combination product that contained several compounds, including Tabebuia and hydroxytyrosol. During three months of treatment, 49 people reported no candida episodes. This is promising but may not apply to people who take Tabebuia alone.
An early in vitro study was also done with plant extracts, including Tabebuia extract, to test their activity against Candida albicans. Tabebuia extract showed inhibition of some fungus strains that cause human disease. These included strains of Candida, Aspergillus, Saccharomyces, and Penicillium.
Viral and parasitic Infections
A review suggested that Tabebuia impetiginosa may have antiviral effects against the human herpes virus and that a compound derived from lapachol may have antiparasitic effects in vitro.
Bacterial infections
An in vitro study tested the antimicrobial effects of lapachol, a compound in pau d’arco. The bacteria tested included ones that could cause severe human infections, such as Enterococcus faecalis, Staphylococcus aureus, Cryptococcus gatti, and Paracoccidioides brasiliensis. Lapachol showed activity against all these microorganisms.
Another in vitro study looked at whether plant medicines like pau d’arco could be used along with some antibiotics to make them more effective. This study tested a combination of Tabebuia avellanedae bark extract and other medicinal plants against bacteria, including Haemophilus influenzae, Staphylococcus aureus, and Klebsiella pneumoniae. Scientists also tested the antibacterial effects of combining medicinal plants with antibiotics. These included clarithromycin, azithromycin, and amoxicillin/clavulanic acid. Results showed that the medicinal plant extracts sometimes increased antibacterial activity, which is a path for future study.
Despite the promising results of these studies, the doses used in many in vitro experiments would be toxic in humans. Further investigation in humans is needed before researchers can draw any firm conclusions.
Wound healing
Researchers studied the wound-healing effects of beta-lapachone, a component of pau d’arco.
Scientists tested the effects of beta-lapachone on mouse cells, human cells, and live mice. Beta-lapachone caused cells to release proteins involved in wound healing. Beta-lapachone ointment used in mice also led to faster recovery than ointment without beta-lapachone added.
Researchers cannot apply these results to humans like the other animal and in vitro studies in this article. They only mean that further research is worthwhile.
Cancer
Compounds in pau d’arco have in vitro evidence for inhibition of the growth of some types of tumors. This is not the same as being effective against cancer in a person.
Check with your healthcare provider before adding integrative treatments to your cancer treatment regimen. Sometimes medicinal herbs can worsen your symptoms or even interact with your cancer medicine. Remember, avoid replacing your cancer treatment with herbal medicine.
Here are some of the research findings.
In a review of studies about Tabebuia impetiginosa, scientists concluded that the beta-lapachone found in pau d’arco was able to trigger apoptosis (programmed cell death) in certain types of cancer cells.
Another in vitro study that treated breast cancer cells with powder from the inner bark of the Tabebuia avellanedae tree had similar results. Scientists reported that breast cancer cells showed increased apoptosis and stopped an enzyme involved in breast cancer called aromatase.
More about apoptosis: All normal cells undergo apoptosis so new cells can replace old cells. Cancer cells, however, are “immortal,” replicating without end. Triggering apoptosis (cell death) can theoretically control cancerous tumors.
Although there is promising evidence from cells and test tubes for future cancer drug discovery, pau d’arco does not yet have evidence for treating or preventing cancer.
What Are the Side Effects of Pau d’Arco?
Little is known about the long-term safety of pau d’arco. However, it does have some side effects of which you need to be aware.
Common Side Effects
Common side effects include dizziness, nausea, vomiting, and diarrhea. The risk and severity of side effects tend to increase with the dose.
Severe Side Effects
Severe allergic reaction is another serious side effect possible with any medication. If you’re having a severe allergic reaction to pau d’arco, get medical help immediately. Symptoms may include but aren’t limited to:
- Difficulty breathingItchinessRash
To avoid interactions or potentially severe side effects, always consult your healthcare provider about any herbal supplement or medication you take. And call 911 if your symptoms feel life-threatening.
Precautions
Pau d’arco may slow blood clotting because it inhibits blood clotting factors that depend on vitamin K.
Any medicine or herb that inhibits clotting or increases the risk of bleeding should be stopped for at least two weeks before surgery. Ask your healthcare provider if any of your medications or supplements also need to be stopped temporarily if you have surgery planned.
Due to the lack of safety research, pau d’arco should not be used in children or during pregnancy or breastfeeding. Limited animal studies showed fetal harm with lapachol.
People with kidney or liver disease should also use it with caution.
Dosage: How Much Pau d’Arco Should I Take?
Pau d’arco is available as capsules, tablets, dried bark tea, bark powder, and alcohol-based tinctures. There are no guidelines directing its appropriate use.
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
Doses that have been researched include 250 milligrams (mg) to 3,750 milligrams (mg) daily. Dosages on various supplement labels include 2.5 millimeters (mL) or 1 millimeter (mL) tincture mixed with water and 1 gram (g) or 500 milligrams (mg) in a capsule.
The dosage can be hard to calculate accurately when it is taken as a tea.
What Happens If I Take Too Much Pau D’Arco?
Information about the toxicity of pau d’arco in humans is sparse.
However, a study in male rats using high levels of Tabebuia impetiginosa extract showed damage to DNA in liver cells. This effect was dose-depenedent, meaning the damage increased as the dose increased.
The exact translation of this information for humans is unclear. However, people with kidney or liver disease should use it cautiously.
Interactions
Because pau d’arco can slow blood clotting, it should not be used with blood thinners like Jantoven (warfarin) or Plavix (clopidogrel).
Non-steroidal anti-inflammatory drugs (NSAIDs) have a theoretical interaction with pau d’arco. Although there have not been published studies about pau d’arco interacting with NSAIDs, it is possible. Any supplement that affects bleeding can increase the risk of bleeding that is already present as a side effect of NSAID use.
Whatever pau d’arco product you buy, it is important to read the label carefully to ensure that it contains Tabebuia avellanedae or Tabebuia impetiginosa as an ingredient.
It is essential to carefully read a supplement’s ingredient list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
How to Store Pau d’Arco
Store pau d’arco in a cool, dry place. Keep pau d’arco away from direct sunlight. Discard as indicated on the packaging.
Similar Supplements
Pau d’arco is available as a whole plant extract or bark, but it also contains quercetin, which is often sold as a separate supplement.
Sources of Pau d’Arco & What To Look For
Pau d’arco supplements are available in drug stores and online. Although it can be hard to be sure that you will always get the exact amount of pau d’arco on the label, you can choose brands that are more reputable. Ask your healthcare provider for recommendations of brands that are known to be tested for impurities.
Frequently Asked Questions
Despite suggestions that pau d’arco may be active against breast cancer and prostate cancer cells, there is no evidence of any such effect in humans. The research has been limited to test-tube studies and a few small animal studies.
We don’t know yet. Although pau d’arco has been studied in animals and test tubes for anti-inflammatory effects, there is no evidence for this use in people yet. Other teas with health benefits and foods with anti-inflammatory effects have been studied more than pau d’arco. Most importantly, consuming a diet high in vegetables and fruit, fiber, enough protein, and whole grains can reduce inflammation. Focus on the diet first to achieve anti-inflammatory effects.
Pau D’Arco Supplements
The forms that pau d’arco comes in include:
- CapsulesTincturesTeas
If you use the tea form, it can be harder to estimate the dosage you are taking.
To ensure quality and safety, opt for supplements independently tested by a certifying body like the U.S. Pharmacopeia (USP), NSF International, or ConsumerLab. The certification confirms that the supplement contains the ingredients and ingredient amounts listed on the product label.
Always read the label to check for added ingredients you may be allergic to or sensitive to, including gluten and animal-based gelatins.
Talk with your healthcare provider first if you’re considering using pau d’arco or making other dietary changes. Self-treating a condition and avoiding or delaying standard care may have serious consequences.
Summary
Pau d’arco is the bark of several species of trees native to the rainforests of Central and South America that has been used in folk medicine.
Research on pau d’arco has mostly been done in vitro and animals. There have been promising results that it may have future potential for treating some types of infections, inflammatory conditions, and cancers. This evidence does not support the use of pau d’arco to treat any conditions in humans yet.
Due to the lack of safety research, pau d’arco should not be used in children, people who are pregnant or breastfeeding, or people with liver or kidney problems. It should also be avoided if you take blood thinners, nonsteroidal anti-inflammatory drugs, or any medical conditions affecting bleeding or clotting.
