Herb & supplement monograph

Ash Drug Interactions, Uses, Effectiveness, Safety & More

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

What is this page for?

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

But these pages have grown well beyond that into a full monograph — what Ash 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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Reviewed by licensed pharmacists Sourced from Natural Medicines

On this page

Ash 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 Ash drug interaction appears low for most people, since every listed concern is theoretical rather than confirmed in humans. None of the interactions are rated major, and although all are graded moderate, each rests on animal research rather than well-documented human findings.

Interactions deserving the most attention

The interactions worth watching involve diabetes medications and blood pressure medications. Animal studies suggest ash seed extract can lower blood sugar, which could in theory add to the effect of diabetes drugs, though a human study in people without diabetes found no meaningful change in glucose. Animal research also shows ash seed extract may lower blood pressure, an effect not yet tested in people. Because blood sugar and blood pressure medicines are dosed carefully, it makes sense to be aware of these possibilities.

What the rest of the list means

The long roster of interacting medications comes from just two broad drug categories, so hundreds of individual medicines inherit the same theoretical concern. These predictions come from animal research, and where human data exists, the expected effect on blood sugar did not appear. A large number here reflects caution, not proven harm.

Check your medications against Ash

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

Interaction report

Drugs that interact with Ash

258 medications have a known interaction with Ash, 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 Ash using our pharmacist-reviewed interaction data.

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

2,830 drugs

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 Ash 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 Ash affects

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

All 2 drug categories Ash interacts with

Antidiabetes DrugsAntihypertensive Drugs

Antidiabetes Drugs

Theoretically, concomitant use with antidiabetes drugs might affect glucose control and increase the risk of hypoglycemia. Dose adjustments to diabetes medications might be necessary. Animal research shows that ash seed/fruit extract reduces fasting levels of glucose. Although clinical research in patients without diabetes shows that ash seed/fruit extract does not significantly affect blood glucose levels, insulin levels, or homeostatic model of insulin resistance (HOMA-IR), it may lower the incremental glucose area under the curve and decrease 2-hour blood glucose following an oral glucose tolerance test. Ash seed/fruit extract has not been evaluated in patients with diabetes. Until more is known, use cautiously in patients taking antidiabetes drugs.
Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others.

Likelihood Possible Evidence D

Antihypertensive Drugs

Theoretically, concomitant use of ash seed with antihypertensive drugs might have additive blood pressure lowering effects. Animal research shows that ash seed extract can decrease blood pressure. This effect has not been evaluated in humans. Until more is known, use cautiously in patients taking antihypertensive drugs.
Some antihypertensive drugs include nifedipine (Adalat, Procardia), verapamil (Calan, Isoptin, Verelan), diltiazem (Cardizem), isradipine (DynaCirc), felodipine (Plendil), amlodipine (Norvasc), and others.

Likelihood Possible Evidence D

Monograph

Ash: Uses, Safety & Side Effects

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

The bottom line

Ash (Fraxinus excelsior and related species) is a tree whose leaves, bark, and seeds have a long history in folk medicine for arthritis, fever, and fluid retention. Solid human evidence is limited for nearly all of these uses, so it should not replace proven treatments. Talk with your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or taking other medicines.

Scientific name: Fraxinus excelsior
Family: Oleaceae
Part used: Leaves, bark, and seeds
Common forms: Tea, dried leaf, capsules, tinctures, extracts

People commonly use it for

Joint pain and arthritis
Fever
Constipation
Fluid retention (diuretic)
Bladder and urinary complaints
Weight management and blood sugar

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

Safety at a glance

OverallUse caution

Likely fine in food amounts, but medicinal use lacks strong safety data.

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.

Jump to a section

Overview

Ash is a large deciduous tree found mainly in Europe and parts of Asia, with related species in North America. It is well known for its strong, flexible wood and its distinctive bark and leaves.

In traditional herbal medicine, the leaves, bark, and seeds of ash have been used to make teas, tinctures, and extracts. People have reached for it to help with joint pain, fever, constipation, and to increase urine output. Today it is sometimes found in herbal supplements, occasionally blended with other plants such as goldenrod or aspen.

How it works

Ash leaves and bark contain plant compounds such as coumarins, flavonoids, secoiridoids (like fraxin and esculin), and tannins. In laboratory and animal studies, some of these compounds have shown antioxidant and anti-inflammatory activity.

Researchers think the possible diuretic and anti-inflammatory effects may come from these natural compounds. However, most of this work has been done in test tubes or animals, so it is not clear how well these effects carry over to people taking ash by mouth.

Effectiveness

Does Ash work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 1 use evaluated

1 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

For Ash, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 1 condition — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Obesity

Rating & evidence shown verbatim from Natural Medicines

A small clinical trial in elderly, overweight and obese patients shows that taking a specific ash seed/fruit extract (Glucevia, Naturex) 1 gram daily for 3 weeks in addition to a calorie-reduced diet does not increase weight loss or improve glycemic or lipid indices over a calorie-reduced diet alone. However, there was a small increase in loss of fat mass.

Sources Ref 100051

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Ash is generally considered low risk when consumed in small, food-like amounts. The safety of larger, concentrated medicinal doses has not been well studied.

People who are allergic to ash pollen or other plants in the olive (Oleaceae) family should be cautious, as allergic reactions are possible. Those with kidney problems should talk to a doctor before using any product marketed as a diuretic.

Pregnancy and breastfeeding: There is not enough reliable safety information for these times, so it is best to avoid ash supplements if you are pregnant or breastfeeding. Always check with a pharmacist or doctor first.

Side effects

Ash is not associated with many reported side effects, partly because it has not been studied much. Possible effects include mild stomach upset or, with its diuretic use, increased urination.

Allergic reactions are possible, especially in people sensitive to ash pollen. Stop using it and seek medical care if you notice rash, itching, swelling, or trouble breathing.

Dosing

There is no well-established standard dose for ash. Amounts vary widely between teas, tinctures, capsules, and extracts.

If you choose to use an ash product, follow the directions on the label and do not exceed them. Because quality and strength can differ between brands, it is a good idea to ask your pharmacist for help choosing and dosing a product safely.

Pregnancy & Breastfeeding

Ash & Pregnancy

Insufficient reliable information

Insufficient reliable information available; avoid using.

Ash & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

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.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 3 references that drive our Ash 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.

Zulet MA, Navas-Carretero S, Lara y Sánchez D, et al. A Fraxinus excelsior L. seeds/fruits extract benefits glucose homeostasis and adiposity related markers in elderly overweight/obese subjects: a longitudinal, randomized, crossover, double-blind,
Montó F, Arce C, Noguera MA, et al. Action of an extract from the seeds of Fraxinus excelsior L. on metabolic disorders in hypertensive and obese animal models. Food Funct. 2014;5(4):786-96. PubMed
Visen P, Saraswat B, Visen A, et al. Acute effects of Fraxinus excelsior L. seed extract on postprandial glycemia and insulin secretion on healthy volunteers. J Ethnopharmacol. 2009;126(2):226-32. PubMed

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 Ash

15 brands in our database make a supplement containing Ash.

Advanced Naturals 68 products Allergy Research Group 1,595 products Biopharma Scientific 22 products DaVinci Benefits Line 62 products Evogen 30 products Genestra Brands 998 products Hawaii Pharm 4,726 products Health Concerns 444 products Herbal Terra 3,138 products NutriCology 678 products OM-CHI Herbs 1 product Renew Life 722 products Sunfood Superfoods 5 products TerraVita Premium Collection 4,019 products UNDA Gemmo 67 products

Product directory

Supplement products with Ash

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

Pharmacist Counseling Corner

Ash: Common Questions

What is Ash used for, and does it work?

People use Ash for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.

Does Ash interact with prescription medications?

Yes. We list 258 medications with a known interaction with Ash. Use the checker above to see how Ash interacts with a specific drug.

How are Ash 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 Ash 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 Ash 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 Ash used for?

Ash leaves, bark, and seeds are traditionally used for joint pain and arthritis, fever, constipation, fluid retention, and urinary complaints. Strong human evidence is lacking for most of these uses.

Is Ash safe to take?

Small, food-like amounts are generally considered low risk, but concentrated supplements have not been well studied. Talk with your pharmacist or doctor before using it, especially if you have kidney problems or plant allergies.

Can I use Ash during pregnancy or breastfeeding?

There is not enough safety information, so it is best to avoid Ash supplements while pregnant or breastfeeding.

Is the Ash supplement related to Ash tree pollen allergies?

Yes, Ash supplements come from the same tree family. If you are allergic to Ash pollen, you may be more likely to react and should be cautious.

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

Keep exploring

Products that contain Ash

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

See all 31 products with Ash →

Where next

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Ash Drug Interactions, Uses, Effectiveness, Safety & More

Your Choice:

Ash Drug Interactions: The Bottom Line

Drugs that interact with Ash

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 Ash affects

Ash: Uses, Safety & Side Effects

Overview

How it works

Does Ash work?

Safety & precautions

Side effects

Dosing

Ash & Pregnancy

Ash & Breastfeeding

References & further reading

Brands that make products with Ash

Supplement products with Ash

Ash: Common Questions

Related supplements & herbs

Products that contain Ash

Have a question about Ash?