Drug & supplement interaction

Northern Prickly Ash + Valacyclovir

Valacyclovir brand name: Valtrex.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Northern Prickly Ash and Valacyclovir 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

Northern Prickly Ash and Valacyclovir

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 Valacyclovir and Northern Prickly Ash 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.

Northern Prickly Ash safety at a glance

Northern Prickly A... overall Use caution Limited safety data exist, so use cautiously and only short-term.
Pregnancy Possibly Unsafe When the bark is used orally; avoid using. There is insufficient reliable information available about the safety of the berry or root during pregnancy; avoid us... Read the full pregnancy detail
Breastfeeding Avoid Not enough safety information; best avoided while breastfeeding.

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 Valacyclovir and Northern Prickly Ash? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Valacyclovir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Valacyclovir is filed under 3 classifications — organic anion transporter 1 (oat1) substrates, seizure threshold lowering drugs, oral drugs. Northern Prickly Ash has documented interactions with 3 drug classes — the most serious being antacids (minor), h2-blockers (minor) and proton pump inhibitors (ppis) (minor) — and none of Valacyclovir’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

Northern Prickly Ash Does Interact With Other Medications

Northern Prickly Ash has 36 minor known drug interactions in our database — Valacyclovir isn’t one of them. If you take anything else, check it against the full list below.

Minor 36 No known interaction 2,794 (incl. Valacyclovir)
Taking anything else?

Check Another of Your Medications Against Northern Prickly Ash

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

What to actually watch for

What Valacyclovir’s Own FDA Label Lists

This is not an interaction — none of it involves Northern Prickly Ash. These are the most notable effects listed in the ADVERSE REACTIONS section of Valacyclovir’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.

  • Mania or an unusually elevated mood Worth acting on
  • Dehydration Worth acting on
  • Unsteadiness Worth acting on
  • Hallucinations Worth acting on
  • Confusion Worth acting on
  • A severe skin reaction Worth acting on
  • Seizures Worth acting on
  • Low mood Worth acting on
  • A low platelet count Worth acting on
  • Kidney problems Worth acting on

Showing the 10 most notable of 35 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 Valacyclovir. Read the label on DailyMed › Northern Prickly Ash’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Northern Prickly Ash side to compare — that is a limit of the record, not a statement that Northern Prickly Ash has no side effects.

Special populations

Northern Prickly Ash in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When the bark is used orally; avoid using. There is insufficient reliable information available about the safety of the berry or root during pregnancy; 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

From our Q&A

Questions About Northern Prickly Ash or Valacyclovir

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Northern Prickly Ash or Valacyclovir, 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 Valacyclovir

This page covers Northern Prickly Ash only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Valacyclovir page lists 27 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), African Wild Potato (moderate), Banderol (moderate), Biofeedback (moderate) and Caffeic Acid (moderate).

By severity: 1 major · 17 moderate · 9 minor.

From our pharmacist’s overview on the Valacyclovir page

“Valacyclovir (Valtrex) works against herpes outbreaks only if enough of it gets absorbed into your blood, and most of this list threatens exactly that. Of the 27 supplements on file, 17 can change how well oral medicines like this one are absorbed, and the single major-rated entry, activated charcoal, binds drugs in the gut outright.”

Reviewed by 2 · Jul 18, 2026

Open the Valacyclovir interaction page

One more smart check

Taking Northern Prickly Ash as Part of a Dietary Supplement Product? Check It for Interactions

We hold 20 real supplement products containing Northern Prickly Ash, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Northern Prickly Ash. Even though Northern Prickly Ash itself has no known interaction with Valacyclovir, 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 Northern Prickly Ash and Valacyclovir 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 Northern Prickly Ash
Steady interest

#1,081 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Valacyclovir
Top 5%

#30 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 Northern Prickly Ash reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Northern Prickly Ash and Valacyclovir 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 Northern Prickly Ash

What is Northern Prickly Ash?

Northern Prickly Ash
  • Toothache and mouth pain
  • Joint pain and rheumatism
  • Digestive upset
  • Poor circulation
  • Cramping

Northern Prickly Ash is a North American shrub whose bark and berries have a long history in folk medicine, especially for toothache, joint pain, and sluggish digestion. Modern scientific evidence for these uses is very limited, coming mostly from traditional reports and laboratory studies. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Zanthoxylum americanum · Rutaceae · Bark and berries (fruit); sometimes leaves · Dried bark, tincture, capsules, tea, fluid extract

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

Northern Prickly Ash: dosing

There is no established standard dose for Northern Prickly Ash. Traditional preparations have varied widely, and product strengths differ between brands.If you choose to use it, follow the directions on the product label and do not exceed the suggested amount.

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

Read the full Northern Prickly Ash monograph & all interactions
Medication

About Valacyclovir

What Is Valacyclovir Used For?

Brand name: Valtrex

Valacyclovir tablets are used in adults to treat cold sores (herpes labialis), genital herpes (initial and recurrent episodes), and shingles (herpes zoster). They can also be taken daily as suppressive therapy to reduce how often genital herpes outbreaks occur, and to lower the risk of passing genital herpes to a partner.

In children and adolescents, valacyclovir tablets are used to treat cold sores in those aged 12 and older, and chickenpox in those aged 2 to under 18. Valacyclovir has not been established as safe and effective for most uses in immunocompromised patients, with the exception of suppressive therapy for genital herpes in HIV-infected adults.

Most-Reported Side Effects for Valacyclovir

From FAERS, the FDA’s public side-effect reporting system (70,056 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 4,317 reports
Nausea 3,985 reports
Diarrhea 3,648 reports
Headache 2,964 reports
Fever 2,753 reports
See full Valacyclovir drug information
Keep checking

Other Drugs & Northern Prickly Ash

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

0Major
0Moderate
36Minor
2,793No known interaction
36 Minor 2,793 No interaction
Minor

36 interactions

No interaction 2,793 drugs checked — show the list

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

Showing the 60 most looked-up of 2,793 medications checked with no known interaction — see the full Northern Prickly Ash list.

See the full Northern Prickly Ash interactions page
See every supplement checked against Valacyclovir, ranked by severity
Evidence & sources

Northern Prickly Ash References

The 2 references that drive our Northern Prickly 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.

  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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 Northern Prickly Ash and Valacyclovir Together: Common Questions

Is it safe to take Northern Prickly Ash with Valacyclovir?
We do not list a known interaction between Northern Prickly Ash and Valacyclovir. 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.
How was the Northern Prickly Ash and Valacyclovir combination checked?
Interactions in our licensed database are recorded against drug classes. Valacyclovir is filed under 3 classifications, and Northern Prickly Ash has documented interactions with 3 drug classes — none of Valacyclovir'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 Northern Prickly Ash interact with any other medications?
Yes. Northern Prickly Ash has 36 documented drug interactions in our database — Valacyclovir 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 Valacyclovir interact with any supplements?
Yes. Valacyclovir has documented interactions with 27 supplements in our database — Northern Prickly Ash is not one of them. The Valacyclovir 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

Northern Prickly Ash monograph Uses, safety profile, and every drug interaction in one place Valacyclovir drug information The full plain-English guide to this medication Valacyclovir supplement interactions Every supplement checked against Valacyclovir, 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 Valacyclovir and Northern Prickly Ash?

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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.