Herb & supplement monograph

Hydrangea Drug Interactions, Uses, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Hydrangea interacts with medications. The heart of this page is the interaction list — every drug Hydrangea is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Hydrangea is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Hydrangea Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Hydrangea drug interaction appears low for most people. Only one interaction has been identified, it is rated moderate rather than major, and it applies to a single medication.

Interactions deserving the most attention

The one combination that genuinely deserves attention is lithium. Hydrangea is thought to have a diuretic (water-removing) effect, and diuretics can reduce how well the kidneys clear lithium, which could allow lithium levels to rise. Because lithium is a closely monitored medicine with a narrow safety margin, even a modest rise in its level can matter, and the prescriber may need to lower the lithium dose. This concern is graded probable, so it carries real weight even though it has not been confirmed in well-controlled human studies.

What the rest of the list means

Unlike many supplements with long interaction lists, hydrangea's profile is unusually short. Its single concern rests on a predicted diuretic mechanism rather than direct human testing of the combination. For people who do not take lithium, no other documented interactions with medications have been reported.

Check your medications against Hydrangea

Based on HelloPharmacist’s Hydrangea interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Hydrangea

1 medication has a known interaction with Hydrangea, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Hydrangea using our pharmacist-reviewed interaction data.

AI summaries are generated from our Hydrangea interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Lithium Carbonate (prescription Drug)Eskalith, Lithium Carbonate

Moderate Lithium

Hydrangea is thought to have diuretic properties.

Read the full Hydrangea + Lithium Carbonate (prescription Drug) interaction Lithium Carbonate (prescription Drug) drug page: uses, dosage & side effects

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Hydrangea combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Hydrangea affects

Every type of medication (drug category) Hydrangea is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 1 drug category Hydrangea interacts with

Lithium

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

Likelihood Probable Evidence D

Monograph

Hydrangea: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Hydrangea root has a long history in folk medicine, mainly for urinary and kidney stone complaints, but there is very little modern human research to confirm it works for any condition. Because safety data are limited and large amounts may be harmful, it is best to talk with a pharmacist or doctor before using it.

Scientific name: Hydrangea arborescens
Family: Hydrangeaceae
Part used: Root and rhizome (underground stem)
Common forms: Dried root, tincture, liquid extract, capsules, tea

People commonly use it for

Kidney and bladder stones
Urinary tract complaints
Enlarged prostate symptoms
Mild diuretic (increasing urine)
Bladder infections (traditional use)

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Human safety data are limited, and large or prolonged doses may cause unwanted effects.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Hydrangea is a flowering shrub commonly grown as a garden ornamental. The type used in herbal medicine is usually Hydrangea arborescens, sometimes called wild hydrangea or smooth hydrangea, which is native to the eastern United States.

In traditional and folk medicine, it is the root and underground stem (rhizome) that are dried and used, not the showy flowers. Native American and early American herbalists used hydrangea root mainly for urinary problems, such as kidney and bladder stones.

Today you may find it sold as a dried herb, tincture, liquid extract, or capsule, often combined with other herbs in products marketed for kidney or urinary health.

Uses & effectiveness

People most often use hydrangea root for urinary tract and kidney concerns, including kidney stones, bladder stones, painful urination, and symptoms of an enlarged prostate. It is also used traditionally as a mild diuretic, meaning something that increases urine flow.

The evidence is weak. These uses come almost entirely from traditional practice and old herbal writings, not from well-designed human studies. There is little to no reliable modern clinical research showing that hydrangea prevents or dissolves kidney stones, shrinks the prostate, or treats urinary infections.

Because the science is so limited, hydrangea should not replace proven treatments. If you have stones, a urinary infection, prostate symptoms, or blood in your urine, see a healthcare professional rather than relying on this herb.

How it works

Hydrangea root contains plant compounds such as flavonoids, coumarins, and saponins, along with a substance sometimes called hydrangin. These may have mild diuretic or anti-inflammatory effects, which is one reason it was traditionally used for urinary complaints.

However, most of what is suggested about how hydrangea works comes from laboratory studies, traditional theory, or animal research, not from carefully controlled human trials. The exact active compounds and how they might affect stones or the urinary tract in people are not well understood.

Safety & precautions

There is not much reliable information about how safe hydrangea is when taken as a supplement, especially over long periods or in large amounts. Some sources warn that the leaves and buds of hydrangea plants may contain cyanide-like compounds and can be toxic if eaten in quantity, so it should never be self-foraged or used casually.

People with kidney disease, those who take water pills (diuretics), and anyone with a serious medical condition should be especially cautious and check with a healthcare provider first.

Pregnancy and breastfeeding: Because there is no good safety data, hydrangea should be avoided if you are pregnant or breastfeeding.

Always tell your pharmacist or doctor about any herbal product you are taking, particularly before surgery or if you have ongoing health problems.

Side effects

Reported side effects are not well studied, but possible effects include stomach upset, nausea, and dizziness. Because it may act as a diuretic, large amounts could in theory affect fluid and electrolyte balance.

Eating large quantities of the plant material may be poisonous. If someone develops symptoms such as severe stomach pain, vomiting, difficulty breathing, or confusion after taking hydrangea, seek medical care right away.

Hydrangea: Reported Adverse Effects

Documented safety reports on Hydrangea from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally, hydrangea may cause gastroenteritis, dizziness, and a feeling of tightness in the chest.

Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

Reports by condition

Vertigo Neurologic/CNS

Orally, hydrangea may cause dizziness.

Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no well-established or standardized dose for hydrangea, because it has not been studied carefully in people. Traditional preparations used the dried root as a tea or tincture, but reliable, specific amounts are not available.

If you choose to use a product, follow the directions on the label and do not exceed them. It is best to speak with a pharmacist or doctor before starting, so they can help you weigh the limited evidence against your own health situation.

Pregnancy & Breastfeeding

Hydrangea & Pregnancy

Insufficient reliable information

Insufficient reliable information available; avoid using.

Hydrangea & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 1 references that drive our Hydrangea monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

Keep reading

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

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.

Brand directory

Brands that make products with Hydrangea

80 brands in our database make a supplement containing Hydrangea.

Sunshine Naturals 150 products Swanson Premium Brand 788 products TerraVita 2,475 products TerraVita Premium Collection 4,019 products Thera-Zyme 26 products Trace Minerals 82 products Trace Minerals Research 311 products Western Herbal and Nutrition 3 products

Product directory

Supplement products with Hydrangea

337 products in our database contain Hydrangea. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

Hydrangea: Common Questions

Does Hydrangea interact with prescription medications?

Yes. We list 1 medication with a known interaction with Hydrangea. Use the checker above to see how Hydrangea interacts with a specific drug.

How are Hydrangea interactions rated?

Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.

Is it safe to take Hydrangea with my medications?

It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.

Where does this Hydrangea interaction information come from?

Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.

What is Hydrangea used for?

It is used in traditional herbal medicine mainly for urinary problems, such as kidney and bladder stones, and sometimes for prostate symptoms. There is little modern research to confirm it works for these uses.

Is Hydrangea safe to take?

Safety information is limited, and large amounts of the plant may be toxic. Use caution, follow product labels, and check with a pharmacist or doctor first, especially if you have kidney problems or take other medicines.

Can I take Hydrangea while pregnant or breastfeeding?

No reliable safety data exist, so it is best to avoid Hydrangea during pregnancy and breastfeeding.

Can I use Hydrangea from my garden as medicine?

No. Garden Hydrangeas should not be eaten or used as medicine, since the leaves and buds can contain toxic compounds. Only commercially prepared products of the medicinal species should ever be considered, and even then with caution.

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

Keep exploring

Products that contain Hydrangea

A rotating sample of real supplements in our database that list Hydrangea — open any to see its full ingredients and every drug interaction we check.

See all 337 products with Hydrangea →

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Hydrangea Drug Interactions, Uses, Safety & More

Your Choice:

Hydrangea Drug Interactions: The Bottom Line

Drugs that interact with Hydrangea

Don’t want to scroll the list? Just ask.

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Likelihood — How Well It’s Documented

Where This Data Comes From

The kinds of drugs Hydrangea affects

Hydrangea: Uses, Safety & Side Effects

Overview

Uses & effectiveness

How it works

Safety & precautions

Side effects

Hydrangea: Reported Adverse Effects

Dosing

Hydrangea & Pregnancy

Hydrangea & Breastfeeding

References & further reading

Brands that make products with Hydrangea

Supplement products with Hydrangea

Hydrangea: Common Questions

Related supplements & herbs

Products that contain Hydrangea

Have a question about Hydrangea?