Drug & supplement interaction

Elm Bark + Obinutuzumab

Obinutuzumab brand name: Gazyva.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated June 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Elm Bark and Obinutuzumab in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Obinutuzumab states a food rule worth keeping to.

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Interaction report

Elm Bark and Obinutuzumab

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Obinutuzumab and Elm Bark in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Elm Bark at all — not against Obinutuzumab, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Elm Bark safety at a glance

Elm Bark overall Use caution Likely low-risk for short-term use in healthy adults, but human safety data are limited.

Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.

Breastfeeding Avoid No reliable safety data while breastfeeding, so avoid use.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Obinutuzumab and Elm Bark? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

What to actually watch for

What Obinutuzumab’s Own FDA Label Lists

This is not an interaction — none of it involves Elm Bark. These are the most notable effects listed in the ADVERSE REACTIONS section of Obinutuzumab’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

High potassium Worth acting on
Low sodium Worth acting on
Low potassium Worth acting on
A low platelet count Worth acting on
Kidney problems Worth acting on
Anemia Worth acting on
A low white blood cell count Worth acting on
Liver problems Worth acting on
A higher chance of infection Worth acting on
An allergic reaction Worth acting on

Showing the 10 most notable of 17 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Obinutuzumab. Read the label on DailyMed › Elm Bark’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Elm Bark side to compare — that is a limit of the record, not a statement that Elm Bark has no side effects.

How to take them

Some Obinutuzumab Products Have a Food Rule — Elm Bark Should Not Break It

At least one FDA label for a product containing Obinutuzumab says to take it on an empty stomach. Most supplements — Elm Bark included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Obinutuzumab on its own and move Elm Bark to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Obinutuzumab products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

650–1,000 mg acetaminophen At least 30 minutes before GAZYVA infusion.

From the Dosage and Administration section of the FDA label we read for Obinutuzumab — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

How much people look this up

Where Elm Bark and Obinutuzumab Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Elm Bark

Steady interest

#1,326 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Obinutuzumab

Steady interest

#2,522 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions. Elm Bark is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Elm Bark reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Elm Bark and Obinutuzumab records this page draws on were last updated June 22, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Elm Bark

What is Elm Bark?

Diarrhea
Gastritis and stomach upset
Mild inflammation
Skin irritation
Sore throat

Elm bark (from Ulmus minor) has a long history in traditional medicine for digestive complaints and minor inflammation, but high-quality human studies are lacking, so its true effectiveness is unknown. It is generally considered low-risk for short-term use in adults, but it should not be confused with slippery elm (Ulmus rubra). Talk to a pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or have a health condition.

Ulmus minor · Ulmaceae · Bark · Dried bark, powder, tea, tincture/liquid extract, capsules

An interaction check asks whether these two react with each other — it does not ask whether Elm Bark is a good idea for someone in your situation. Here is what our Elm Bark record says about it on its own.

Elm Bark: dosing

There is no well-established standard dose for elm bark. Because human studies are lacking, no reliable, evidence-based amount has been set.If you use a commercial product, follow the directions on the label and do not exceed the recommended amount. Use it for short periods only, and stop if you have any unwanted effects.

From our Elm Bark monograph — the full record covers uses, side effects and every documented interaction.

Read the full Elm Bark monograph & all interactions

Medication

About Obinutuzumab Injection

What Is Obinutuzumab Injection Used For?

Brand name: Gazyva

Gazyva is used to treat three conditions. For chronic lymphocytic leukemia (CLL), it is given in combination with chlorambucil in patients who have not been treated before. For follicular lymphoma (FL), it is used either with bendamustine (for patients whose disease came back or stopped responding to a rituximab-based regimen) or with chemotherapy (for previously untreated advanced disease) — in both cases followed by Gazyva alone as maintenance therapy.

Gazyva is also approved for active lupus nephritis — a type of kidney inflammation caused by lupus — in adults who are already receiving standard therapy for the condition.

See full Obinutuzumab Injection drug information

Keep checking

Other Drugs & Elm Bark

Browse every other medication we’ve checked against Elm Bark — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major

0Moderate

0Minor

2,829No known interaction

2,829 No interaction

No interaction 2,829 drugs checked — show the list

We also checked Elm Bark against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Elm Bark list.

See the full Elm Bark interactions page

See every supplement checked against Obinutuzumab, ranked by severity

Evidence & sources

Elm Bark References

The 2 sources that drive our Elm Bark monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Elm Bark is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

Slippery Elm — MedlinePlus (NIH) Source
Herbs at a Glance — NIH NCCIH Source

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Elm Bark and Obinutuzumab Together: Common Questions

Is it safe to take Elm Bark with Obinutuzumab?

We do not list a known interaction between Elm Bark and Obinutuzumab. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

Should I take Elm Bark and Obinutuzumab at the same time of day?

At least one FDA label for a product containing Obinutuzumab says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Obinutuzumab on its own and move Elm Bark to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.

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

Where next

Keep Exploring

Elm Bark monograph Uses, safety profile, and every drug interaction in one place Obinutuzumab Injection drug information The full plain-English guide to this medication Obinutuzumab supplement interactions Every supplement checked against Obinutuzumab, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Obinutuzumab and Elm Bark?

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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.