Drug & supplement interaction

Low Oxalate Diet + Phenylephrine

Phenylephrine brand names: Gilchew, AH Chew D, Gilchew IR, Sudafed PE, Biorphen.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Low Oxalate Diet and Phenylephrine 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.

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Interaction report

Low Oxalate Diet and Phenylephrine

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 Phenylephrine and Low Oxalate Diet in our sources. This does not guarantee that the combination is completely free of risk — research on Low Oxalate Diet alongside specific medications may be limited.

Worth understanding: our licensed dataset holds no drug-interaction record for Low Oxalate Diet at all — not against Phenylephrine, 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.

Low Oxalate Diet is an eating pattern rather than something you take. Ask your pharmacist or doctor before changing how you eat while on a prescribed medicine: some medicines are dosed around meals, and a change in diet can change how they work. 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.

Low Oxalate Diet safety at a glance

Low Oxalate Diet overall Use caution Generally safe for most adults but can be overly restrictive and may unbalance nutrition if not planned well.
Pregnancy Use caution Discuss any restrictive diet with your provider during pregnancy to be sure nutrient needs are met.
Breastfeeding Use caution Work with a provider to keep your diet balanced while nursing.

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

Still wondering about combining Phenylephrine and Low Oxalate Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Phenylephrine’s Own FDA Label Lists

This is not an interaction — none of it involves Low Oxalate Diet. These are the most notable effects listed in the ADVERSE REACTIONS section of Phenylephrine’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 follow Low Oxalate Diet and take the medicine. 3 of them are worth acting on rather than waiting out — marked below.

  • A slow heartbeat Worth acting on
  • Shortness of breath Worth acting on mentioned in 6.2% of FDA reports for Phenylephrine
  • Raised blood pressure Worth acting on
  • Blurred vision
  • Headache mentioned in 7.8% of FDA reports for Phenylephrine
  • Nausea mentioned in 7.6% of FDA reports for Phenylephrine
  • Vomiting

From the ADVERSE REACTIONS section of the FDA label for Phenylephrine. Read the label on DailyMed › Where a percentage is shown, it is the share of 221,388 voluntary FDA FAERS reports for Phenylephrine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Low Oxalate Diet’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Low Oxalate Diet side to compare — that is a limit of the record, not a statement that Low Oxalate Diet has no side effects.

From our Q&A

Questions About Low Oxalate Diet or Phenylephrine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Low Oxalate Diet or Phenylephrine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Phenylephrine

This page covers Low Oxalate Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenylephrine page lists 81 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Lithium (major), Peyote (major) and Rauvolfia Vomitoria (major).

By severity: 6 major · 60 moderate · 15 minor.

From our pharmacist’s overview on the Phenylephrine page

“If you take phenylephrine (Sudafed PE, Biorphen) for congestion, treat this list as one that needs real attention, since six of its 81 entries carry a major rating. Phenylephrine tightens blood vessels to clear your nose, and more than half of the interactions here come from stimulant ingredients, ephedra above all, that can push blood…”

Reviewed by 2 · Jul 18, 2026

Open the Phenylephrine interaction page

How much people look this up

Where Low Oxalate Diet and Phenylephrine 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 Low Oxalate Diet
Steady interest

#1,229 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phenylephrine
Top 25%

#507 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 Low Oxalate Diet reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Low Oxalate Diet and Phenylephrine 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 .
Eating pattern

About Low Oxalate Diet

What is Low Oxalate Diet?

  • Prevention of calcium-oxalate kidney stones
  • Reducing high urine oxalate levels
  • Management of recurrent kidney stones
  • Hyperoxaluria

A low oxalate diet limits foods high in oxalate (like spinach, rhubarb, nuts, and certain beans) to help lower the amount of oxalate in your urine. It is most often recommended for people who form calcium-oxalate kidney stones, but it works best alongside other steps like staying well hydrated and getting enough dietary calcium. Talk with your doctor, pharmacist, or a dietitian before making major diet changes.

Dietary plan (meal planning, food lists)

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

Low Oxalate Diet: dosing

There is no single "dose" for a low oxalate diet. Recommendations vary, but a common approach is to limit total daily oxalate intake and focus on avoiding the highest-oxalate foods. Because exact targets differ from person to person, your provider or dietitian can set a goal that fits you.General supportive steps often recommended alongside the diet include drinking enough fluid to keep urine pale, getting adequate calcium from food, and limiting excess salt and animal protein.

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

Read the full Low Oxalate Diet monograph & all interactions
Medication

About Phenylephrine

What Is Phenylephrine Used For?

Brand names: Gilchew, AH Chew D, Gilchew IR, Sudafed PE, Biorphen

Phenylephrine is used in several different products, and each one has its own use.

Injection (IV): raises blood pressure in adults with clinically important hypotension (low blood pressure) caused mainly by widened blood vessels. Some injections are labeled for anesthesia only. Others are labeled for anesthesia and septic shock.

Eye drops: Phenylephrine Hydrochloride Ophthalmic Solution is used to dilate the pupil.

Nasal products: temporarily relieve nasal and sinus congestion from the common cold, hay fever or other upper respiratory allergies.

Rectal suppositories: relieve itching, burning and discomfort from hemorrhoids and temporarily shrink hemorrhoidal tissue.

Most-Reported Side Effects for Phenylephrine

From FAERS, the FDA’s public side-effect reporting system (221,388 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 20,609 reports
Headache 17,301 reports
Nausea 16,925 reports
Diarrhea 14,221 reports
Dyspnea 13,719 reports
See full Phenylephrine drug information
Keep checking

Other Drugs & Low Oxalate Diet

Browse every other medication we’ve checked against Low Oxalate Diet — 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 Low Oxalate Diet 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 Low Oxalate Diet list.

See the full Low Oxalate Diet interactions page
See every supplement checked against Phenylephrine, ranked by severity
Evidence & sources

Low Oxalate Diet References

The 6 references that drive our Low Oxalate Diet 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. Noori N, Honarkar E, Goldfarb DS, et al. Urinary lithogenic risk profile in recurrent stone formers with hyperoxaluria: a randomized controlled trial comparing DASH (Dietary Approaches to Stop Hypertension)-style and low-oxalate diets. Am J Kidney Dis. 20 PubMed
  2. Gleeson MJ, Thompson S, Mehta S, Griffith DP. Effect or unprocessed wheat bran on calciuria and oxaluria in patients with urolithiasis. Urology. 1990 March;35(3):231-4.
  3. Thomas E, von Unruh GE, Hesse A. Influence of a low- and a high-oxalate vegetarian diet on intestinal oxalate absorption and urinary excretion. Eur J Clin Nutr. 2008 Sep;62(9):1090-7. PubMed
  4. Zimmermann DJ, Hesse A, von Unruh GE. Influence of a high-oxalate diet on intestinal oxalate absorption. World J Urol. 2005 Nov;23(5):324-9. PubMed
  5. Baggish MS, Sze EH, Johnson R. Urinary oxalate excretion and its role in vulvar pain syndrome. Am J Obstet Gynecol. 1997 Sep;177(3):507-11. PubMed
  6. Awad-Igbaria Y, Palzur E, Nasser M, Vieira-Baptista P, Bornstein J. Changes in the Vaginal Microbiota of Women With Secondary Localized Provoked Vulvodynia. J Low Genit Tract Dis 2022;26(4):339-344. 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

Following Low Oxalate Diet While Taking Phenylephrine: Common Questions

Is it safe to follow Low Oxalate Diet while taking Phenylephrine?
We do not list a known interaction between Low Oxalate Diet and Phenylephrine. 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.
Does Phenylephrine interact with any supplements?
Yes. Phenylephrine has documented interactions with 81 supplements in our database — Low Oxalate Diet is not one of them. The Phenylephrine 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

Low Oxalate Diet monograph Uses, safety profile, and every drug interaction in one place Phenylephrine drug information The full plain-English guide to this medication Phenylephrine supplement interactions Every supplement checked against Phenylephrine, 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 Phenylephrine and Low Oxalate Diet?

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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.