Drug & supplement interaction

Parsnip + Obinutuzumab

Obinutuzumab brand name: Gazyva.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Parsnip 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

Parsnip 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 Parsnip 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 Parsnip 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.

Parsnip safety at a glance

Parsnip overall Use caution Safe as a food, but its leaves, sap, and seeds contain compounds that can cause skin reactions with sun exposure.
Pregnancy Use caution Fine as a normal food, but avoid concentrated supplement or medicinal amounts due to lack of safety data.
Breastfeeding Use caution Safe as a food, but the safety of medicinal or concentrated amounts is not known.

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

Still wondering about combining Obinutuzumab and Parsnip? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Parsnip Itself Has Been Linked To

This is not an interaction — nothing below involves Obinutuzumab. It is the side-effect record for Parsnip on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Parsnip, this list is the first place to look.

  • Swelling Additional detail

    “Topically, contact dermatitis and phototoxic reactions, including skin blisters and later hyperpigmentation, have occurred following exposure to parsnip sap or fresh parsnip root and exposure to sunlight or UV-A light from a sunbed. Light-skinned people may be particularly susceptible to these reactions.

    A case report describes a 51-year-old male who developed rashes on his hands after preparing parsnip.”

    Parsnip · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 10071. Ivie GW, Holt DL, Ivey MC. Natural toxicants in human foods: psoralens in raw and cooked parsnip root. Science 1981;213:909-10.. PubMed
    2. 68289. Lutchman, L., Inyang, V., and Hodgkinson, D. Phytophotodermatitis associated with parsnip picking. J.Accid.Emerg.Med. 1999;16(6):453-454. PubMed
    3. 68291. Aberer, W. Occupational dermatitis from organically grown parsnip (Pastinaca sativa L.). Contact Dermatitis 1992;26(1):62.
    4. 68295. Bang, Pedersen N. and Pla Arles, U. B. Phototoxic reaction to parsnip and UV-A sunbed. Contact Dermatitis 1998;39(2):97. PubMed
    5. 111192. White JML, Pink AE. English Sunday lunch dermatitis: Allergic contact dermatitis to parsnip, carrot, fennel (and ivy). Contact Dermatitis. 2020 Oct;83(4):317-8. PubMed
    6. 111193. Lafon A, Boulard C. Perioral phytophotodermatitis induced by parsnip mash. Contact Dermatitis. 2020 Oct;83(4):318-9. PubMed
  • A skin rash Additional detail

    “Topically, contact dermatitis and phototoxic reactions (including skin blisters) are possible following exposure to parsnip sap or fresh parsnip root and exposure to sunlight. Allergic contact dermatitis can occur but is rare.”

    Parsnip · Natural Medicines adverse-effect record, reported in dermatitis.

    4 sources cited
    1. 10071. Ivie GW, Holt DL, Ivey MC. Natural toxicants in human foods: psoralens in raw and cooked parsnip root. Science 1981;213:909-10.. PubMed
    2. 68289. Lutchman, L., Inyang, V., and Hodgkinson, D. Phytophotodermatitis associated with parsnip picking. J.Accid.Emerg.Med. 1999;16(6):453-454. PubMed
    3. 68291. Aberer, W. Occupational dermatitis from organically grown parsnip (Pastinaca sativa L.). Contact Dermatitis 1992;26(1):62.
    4. 68295. Bang, Pedersen N. and Pla Arles, U. B. Phototoxic reaction to parsnip and UV-A sunbed. Contact Dermatitis 1998;39(2):97. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Parsnip — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Obinutuzumab’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Obinutuzumab column appears here.

How to take them

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

At least one FDA label for a product containing Obinutuzumab says to take it on an empty stomach. Most supplements — Parsnip 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 Parsnip 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. See the Obinutuzumab drug page ›

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.

One more smart check

Taking Parsnip as Part of a Dietary Supplement Product? Check It for Interactions

We hold 38 real supplement products containing Parsnip, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Parsnip. Even though Parsnip itself has no known interaction with Obinutuzumab, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Parsnip 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 Parsnip
Steady interest

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

29 days ago today
Medication Obinutuzumab
Steady interest

#2,267 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.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Parsnip reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Parsnip and Obinutuzumab records this page draws on were last updated July 10, 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 .
Supplement

About Parsnip

What is Parsnip?

  • Digestive support
  • Mild diuretic ('water pill') effect
  • Nutritional/dietary fiber source
  • Traditional kidney and urinary support
  • General wellness

Parsnip is mainly a nutritious root vegetable that is safe and healthy as part of a normal diet. Its use as a concentrated supplement or herbal remedy is not well studied, and certain parts of the plant can make skin very sensitive to sunlight. Talk to your pharmacist or doctor before using parsnip in any medicinal or high-dose form.

Pastinaca sativa · Apiaceae · Root, leaves, seeds, and essential oil · Whole root (food), cooked vegetable, juice, dried seeds, and rarely supplements or essential oil

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

Parsnip: dosing

There is no established medicinal dose for parsnip. As a food, it is simply eaten as a vegetable in normal serving amounts.If you choose to use a parsnip supplement, juice, or extract, there is no standardized dose backed by research.

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

Read the full Parsnip 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 & Parsnip

Browse every other medication we’ve checked against Parsnip — 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 Parsnip 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 Parsnip list.

See the full Parsnip interactions page
See every supplement checked against Obinutuzumab, ranked by severity
Evidence & sources

Parsnip References

The 6 references that drive our Parsnip 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.

  1. Ivie GW, Holt DL, Ivey MC. Natural toxicants in human foods: psoralens in raw and cooked parsnip root. Science 1981;213:909-10.. PubMed
  2. Lutchman, L., Inyang, V., and Hodgkinson, D. Phytophotodermatitis associated with parsnip picking. J.Accid.Emerg.Med. 1999;16(6):453-454. PubMed
  3. Aberer, W. Occupational dermatitis from organically grown parsnip (Pastinaca sativa L.). Contact Dermatitis 1992;26(1):62.
  4. Bang, Pedersen N. and Pla Arles, U. B. Phototoxic reaction to parsnip and UV-A sunbed. Contact Dermatitis 1998;39(2):97. PubMed
  5. White JML, Pink AE. English Sunday lunch dermatitis: Allergic contact dermatitis to parsnip, carrot, fennel (and ivy). Contact Dermatitis. 2020 Oct;83(4):317-8. PubMed
  6. Lafon A, Boulard C. Perioral phytophotodermatitis induced by parsnip mash. Contact Dermatitis. 2020 Oct;83(4):318-9. PubMed

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 Parsnip and Obinutuzumab Together: Common Questions

Is it safe to take Parsnip with Obinutuzumab?
We do not list a known interaction between Parsnip 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 Parsnip 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 Parsnip 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

Parsnip 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 6 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Obinutuzumab and Parsnip?

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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.