Drug & supplement interaction

Asparagus + Phenazopyridine

Phenazopyridine brand names: Pyridium, Azo-Standard, Phenazo, UTI Relief.

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 Asparagus and Phenazopyridine 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 two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Asparagus and Phenazopyridine

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 Phenazopyridine and Asparagus 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.

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.

Asparagus safety at a glance

Asparagus overall Generally safe Asparagus is safe for most people when eaten as a food, but concentrated extracts are less well studied.
Pregnancy Likely Safe When used in amounts commonly found in foods. Read the full pregnancy detail
Breastfeeding Likely Safe When used in amounts commonly found in foods. There is insufficient reliable information available about the safety of asparagus when used in medicinal amounts... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Phenazopyridine and Asparagus? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Phenazopyridine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Phenazopyridine is filed under a single classification — oral drugs. Asparagus has documented interactions with 2 drug classes — the most serious being diuretic drugs (moderate) and lithium (moderate) — and none of Phenazopyridine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Asparagus Does Interact With Other Medications

Asparagus has 76 moderate known drug interactions in our database — Phenazopyridine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 76 No known interaction 2,754 (incl. Phenazopyridine)
Taking anything else?

Check Another of Your Medications Against Asparagus

Covers the 2,830 medications we’ve checked against Asparagus. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Asparagus and Phenazopyridine May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • An allergic reaction Worth acting on Additional detail

    Asparagus

    “Orally and topically, asparagus can cause allergic reactions. They can occur in individuals sensitive to other members of the Liliaceae family, including onions, garlic, leeks, and chives. Ingestion of fresh or canned asparagus can cause itchy eyes, runny nose, coughing, urticaria, dysphagia, dyspnea, and anaphylaxis in sensitized people.”

    Asparagus · Natural Medicines adverse-effect record, reported in asthma.

    6 sources cited
    1. 15557. Volz T, Berner D, Weigert C, et al. Fixed food eruption caused by asparagus. J Allergy Clin Immunol 2005;116:1390-2. PubMed
    2. 15561. Rieker J, Ruzicka T, Neumann NJ, Homey B. Protein contact dermatitis to asparagus. J Allergy Clin Immunol 2004;113:354-5. PubMed
    3. 15562. Tabar AI, Alvarez-Puebla MJ, Gomez B, et al. Diversity of asparagus allergy: clinical and immunological features. Clin Exp Allergy 2004;34:131-6. PubMed
    4. 15564. Rademaker M, Yung A. Contact dermatitis to Asparagus officinalis. Australas J Dermatol 2000;41:262-3.
    5. 32536. Misico, R. I., Nicotra, V. E., Oberti, J. C., Barboza, G., Gil, R. R., and Burton, G. Withanolides and related steroids. Prog.Chem.Org.Nat.Prod. 2011;94:127-229.
    6. 32594. Escribano MM, Munoz-Bellido FJ, Serrano P, et al. Acute urticaria after ingestion of asparagus. Allergy 1998;53(6):622-623. PubMed

    Phenazopyridine

    Listed in the ADVERSE REACTIONS section of the FDA label for Phenazopyridine. Read the label on DailyMed ›

  • A skin rash Additional detail

    Asparagus

    Recorded for Asparagus in the same Natural Medicines adverse-effect record shown under An allergic reaction above.

    Phenazopyridine

    Listed in the ADVERSE REACTIONS section of the FDA label for Phenazopyridine. Read the label on DailyMed ›

  • Nausea Additional detail

    Asparagus

    “Orally, a specific combination product (Asparagus-P, Grunwalder) containing asparagus root 6 grams and parsley leaf 6 grams caused constipation, abdominal distension and pain, nausea, dry mouth, and gallbladder complaints in up to 50% of the study population in one clinical trial. It is not clear if these effects were due to asparagus root, parsley, or the combination.”

    Asparagus · Natural Medicines adverse-effect record, reported in constipation.

    1 source cited
    1. 94940. Chrubasik S, Droste C, Black A. Asparagus P(R) cannot compete with first-line diuretics in lowering the blood pressure in treatment-requiring antihypertensives. Phytother Res 2009;23:1345-6.

    Phenazopyridine

    Listed in the ADVERSE REACTIONS section of the FDA label for Phenazopyridine. Read the label on DailyMed ›

Reported for Asparagus but not commonly for Phenazopyridine: bloating or gas, constipation, a severe allergic reaction and a stuffy or runny nose.

Effects for Phenazopyridine come from the ADVERSE REACTIONS section of its FDA label; effects for Asparagus come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Asparagus in Pregnancy & Breastfeeding

Pregnancy Likely Safe

When used in amounts commonly found in foods.

Pregnancy Possibly Unsafe

When used in larger amounts for medicinal purposes. Asparagus extracts may have contraceptive effects; avoid using.

Lactation Likely Safe

When used in amounts commonly found in foods. There is insufficient reliable information available about the safety of asparagus when used in medicinal amounts during lactation.

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

Everything else you take

See Every Supplement That Interacts With Phenazopyridine

This page covers Asparagus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenazopyridine page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Phenazopyridine page

“Phenazopyridine (Pyridium, Azo-Standard) only eases urinary burning while enough of it reaches your bladder, and every one of the 17 supplements on this list can interfere with that by changing how the drug is absorbed. Activated charcoal is the standout, the single major-rated entry, because it can bind the drug in the gut and sharply…”

Reviewed by 2 · Jul 18, 2026

Open the Phenazopyridine interaction page

One more smart check

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

We hold 1,414 real supplement products containing Asparagus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Asparagus. Even though Asparagus itself has no known interaction with Phenazopyridine, 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 Asparagus and Phenazopyridine 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 Asparagus
Top 25%

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

29 days ago today
Medication Phenazopyridine
Steady interest

#2,315 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 Asparagus reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Asparagus and Phenazopyridine records this page draws on were last updated July 11, 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 Asparagus

What is Asparagus?

Asparagus
  • Mild fluid retention (diuretic)
  • Urinary tract support
  • Digestive health and fiber
  • General antioxidant and nutritional support
  • Traditional 'detox' or cleansing use

Asparagus is a nutritious vegetable that is safe and healthy to eat as part of a normal diet. Most of its claimed medicinal benefits, such as use as a diuretic or for urinary health, come from traditional use and early lab studies rather than strong human research. If you are considering concentrated asparagus supplements or extracts, talk to your pharmacist or doctor first.

Asparagus officinalis · Asparagaceae · Shoots (spears), rhizome, root, and juice · Whole vegetable (food), capsules, powders, extracts, tea, and juice

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

Asparagus: dosing

There is no standardized or proven medicinal dose for asparagus. As a vegetable, it can be eaten freely as part of a balanced diet.For supplements, extracts, powders, or teas, follow the directions on the product label, since strengths vary widely between products.

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

Read the full Asparagus monograph & all interactions
Medication

About Phenazopyridine

What Is Phenazopyridine Used For?

Brand names: Pyridium, Azo-Standard, Phenazo, UTI Relief

Phenazopyridine treats the symptoms of lower urinary tract irritation — pain, burning, urgency, and frequent urination. These symptoms can result from a urinary tract infection (UTI), trauma, surgery, endoscopic procedures, or the passage of catheters or other instruments.

It is a pain reliever only — it does not treat the underlying infection or cause. When used alongside an antibiotic for a UTI, treatment should not exceed 2 days, and it should be stopped once symptoms are controlled. It must not replace antibiotics or other needed treatment.

See full Phenazopyridine drug information
Keep checking

Other Drugs & Asparagus

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

0Major
76Moderate
0Minor
2,753No known interaction
76 Moderate 2,753 No interaction
Moderate

76 interactions

Showing 60 of 76 moderate interactions — see all 76 on the Asparagus page.

No interaction 2,753 drugs checked — show the list

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

Showing the 60 most looked-up of 2,753 medications checked with no known interaction — see the full Asparagus list.

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

Asparagus References

The 14 references that drive our Asparagus 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  3. Volz T, Berner D, Weigert C, et al. Fixed food eruption caused by asparagus. J Allergy Clin Immunol 2005;116:1390-2. PubMed
  4. Huang X, Kong L. Steroidal saponins from roots of Asparagus officinalis. Steroids 2006;71:171-6. PubMed
  5. Rodriguez R, Jaramillo S, Rodriguez G, et al. Antioxidant activity of ethanolic extracts from several asparagus cultivars. J Agric Food Chem 2005;53:5212-7. PubMed
  6. Rieker J, Ruzicka T, Neumann NJ, Homey B. Protein contact dermatitis to asparagus. J Allergy Clin Immunol 2004;113:354-5. PubMed
  7. Tabar AI, Alvarez-Puebla MJ, Gomez B, et al. Diversity of asparagus allergy: clinical and immunological features. Clin Exp Allergy 2004;34:131-6. PubMed
  8. Rademaker M, Yung A. Contact dermatitis to Asparagus officinalis. Australas J Dermatol 2000;41:262-3.
  9. Misico, R. I., Nicotra, V. E., Oberti, J. C., Barboza, G., Gil, R. R., and Burton, G. Withanolides and related steroids. Prog.Chem.Org.Nat.Prod. 2011;94:127-229.
  10. Hausen BM, Wolf C. 1,2,3-Trithiane-5-carboxylic acid, a first contact allergen from Asparagus officinalis (Liliaceae). Am J Contact Dermat 1996;7(1):41-46. PubMed
  11. Escribano MM, Munoz-Bellido FJ, Serrano P, et al. Acute urticaria after ingestion of asparagus. Allergy 1998;53(6):622-623. PubMed
  12. Chrubasik S, Droste C, Black A. Asparagus P(R) cannot compete with first-line diuretics in lowering the blood pressure in treatment-requiring antihypertensives. Phytother Res 2009;23:1345-6.
  13. Gaus BM, Scheiba N, Schäkel K. Asparagus-induced fixed food eruptions mimicking cutaneous lupus. Acta Derm Venereol 2014;94:731-2. PubMed
  14. Yanagi T, Shimizu H, Shimizu T. Occupational contact dermatitis caused by asparagus. Contact Dermatitis 2010;63:54. 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 Asparagus and Phenazopyridine Together: Common Questions

Is it safe to take Asparagus with Phenazopyridine?
We do not list a known interaction between Asparagus and Phenazopyridine. 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.
Do Asparagus and Phenazopyridine have any of the same side effects?
Yes — our sources link each of them separately to 3 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Asparagus and Phenazopyridine combination checked?
Interactions in our licensed database are recorded against drug classes. Phenazopyridine is filed under 1 classification, and Asparagus has documented interactions with 2 drug classes — none of Phenazopyridine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Asparagus interact with any other medications?
Yes. Asparagus has 76 documented drug interactions in our database — Phenazopyridine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Phenazopyridine interact with any supplements?
Yes. Phenazopyridine has documented interactions with 17 supplements in our database — Asparagus is not one of them. The Phenazopyridine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Asparagus monograph Uses, safety profile, and every drug interaction in one place Phenazopyridine drug information The full plain-English guide to this medication Phenazopyridine supplement interactions Every supplement checked against Phenazopyridine, 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 14 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Phenazopyridine and Asparagus?

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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.