Drug & supplement interaction

Wormwood + 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 Wormwood 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. 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

Wormwood 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 Wormwood 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.

Wormwood safety at a glance

Wormwood overall Use caution Short-term use of properly prepared products may be acceptable, but the thujone in wormwood can be toxic in higher amounts.
Pregnancy Avoid Wormwood may stimulate the uterus and is considered unsafe during pregnancy.
Breastfeeding Avoid There is not enough safety information, so it is best avoided while breastfeeding.

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

Still wondering about combining Valacyclovir and Wormwood? 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. Wormwood has documented interactions with 1 drug class — the most serious being anticonvulsants (moderate) — 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

Wormwood Does Interact With Other Medications

Wormwood has 50 moderate known drug interactions in our database — Valacyclovir isn’t one of them. If you take anything else, check it against the full list below.

Moderate 50 No known interaction 2,780 (incl. Valacyclovir)
Taking anything else?

Check Another of Your Medications Against Wormwood

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

What to actually watch for

No Interaction Found — But Data Suggests Wormwood and Valacyclovir 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. 3 of them are worth acting on rather than waiting out — marked below.

  • Hallucinations Worth acting on Additional detail

    Wormwood

    “Chronic ingestion of absinthe, an alcoholic beverage that contains wormwood extract, has been linked to absinthism. Absinthism was first described in the 1800s when absinthe was at its peak levels of consumption. It has been characterized by addiction, gastrointestinal adverse effects, insomnia, auditory and visual hallucinations, tremors, paralysis, epilepsy, and brain damage.”

    Wormwood · Natural Medicines adverse-effect record, reported in alcohol use disorder.

    6 sources cited
    1. 662. Weisbord SD, Soule JB, Kimmel PL. Poison on line-acute renal failure caused by oil of wormwood purchased through the internet. N Engl J Med 1997;337:825-7. PubMed
    2. 12814. Gambelunghe C, Melai P. Absinthe: enjoying a new popularity among young people? Forensic Sci Int 2002;130:183-6.
    3. 15008. Padosch SA, Lachenmeier DW, Kroner LU. Absinthism: a fictitious 19th century syndrome with present impact. Subst Abuse Treat Prev Policy 2006;1:14. PubMed
    4. 86541. Dettling, A., Grass, H., Schuff, A., Skopp, G., Strohbeck-Kuehner, P., and Haffner, H. T. Absinthe: attention performance and mood under the influence of thujone. J Stud.Alcohol 2004;65(5):573-581. PubMed
    5. 86543. Benezet-Mazuecos, J. and de la Fuente, A. Electrocardiographic findings after acute absinthe intoxication. Int J Cardiol. 11-10-2006;113(2):e48-e50. PubMed
    6. 15007. Lachenmeier DW, Walch SG, Padosch SA, Kroner LU. Absinthe--a review. Crit Rev Food Sci Nutr 2006;46:365-77.

    Valacyclovir

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

  • Seizures Worth acting on Additional detail

    Wormwood

    “Wormwood contains thujone, a neurotoxin. When products containing thujone are used orally in medicinal amounts, wormwood may be unsafe.

    Most Common Adverse Effects:

    Orally: The oil from wormwood leaves can cause diffuse muscle aches, nausea, and vomiting.

    Serious Adverse Effects (Rare):

    Orally: The oil from wormwood leaves can cause acute kidney toxicity, rhabdomyolysis, and seizures.”

    Wormwood · Natural Medicines adverse-effect record, reported in epilepsy.

    Valacyclovir

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

  • Kidney problems Worth acting on Additional detail

    Wormwood

    “Orally, the oil from wormwood leaves can cause acute kidney toxicity and acute kidney failure.”

    Wormwood · Natural Medicines adverse-effect record, reported in kidney failure.

    1 source cited
    1. 662. Weisbord SD, Soule JB, Kimmel PL. Poison on line-acute renal failure caused by oil of wormwood purchased through the internet. N Engl J Med 1997;337:825-7. PubMed

    Valacyclovir

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

  • Anxiety or restlessness Additional detail

    Wormwood

    Recorded for Wormwood in the same Natural Medicines adverse-effect record shown under Hallucinations above.

    Valacyclovir

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

  • Diarrhea Additional detail

    Wormwood

    “Orally, the oil from wormwood leaves can cause nausea and vomiting. Use of a home-prepared wormwood extract has been associated with vomiting and severe diarrhea in an infant.”

    Wormwood · Natural Medicines adverse-effect record, reported in diarrhea.

    2 sources cited
    1. 662. Weisbord SD, Soule JB, Kimmel PL. Poison on line-acute renal failure caused by oil of wormwood purchased through the internet. N Engl J Med 1997;337:825-7. PubMed
    2. 93467. Kocaoglu C, Ozel A. Persistent metabolic acidosis and severe diarrhoea due to Artemisia absinthium poisoning. J Pak Med Assoc. 2014 Sep;64(9):1081-3.

    Valacyclovir

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

  • Vomiting / Nausea Additional detail

    Wormwood

    Recorded for Wormwood in the same Natural Medicines adverse-effect record shown under Seizures above.

    Valacyclovir

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

Reported for Wormwood but not commonly for Valacyclovir: severe muscle breakdown, muscle pain and trouble sleeping.

Effects for Valacyclovir come from the ADVERSE REACTIONS section of its FDA label; effects for Wormwood 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.

From our Q&A

Questions About Wormwood 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 Wormwood 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 Wormwood 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 Wormwood as Part of a Dietary Supplement Product? Check It for Interactions

We hold 387 real supplement products containing Wormwood, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Wormwood. Even though Wormwood 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 Wormwood 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 Wormwood
Top 25%

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

29 days ago today
Medication Valacyclovir
Top 5%

#31 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 Wormwood reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Wormwood 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 Wormwood

What is Wormwood?

Wormwood
  • Digestive upset and poor appetite
  • Intestinal parasites
  • Crohn's disease symptoms
  • Bitter tonic for indigestion
  • Flavoring in absinthe and vermouth

Wormwood is a very bitter herb traditionally used to stimulate appetite and ease digestion, and it has early research interest in Crohn's disease. It contains thujone, which can be toxic in large amounts, so it should only be used short-term in controlled doses. Talk to a pharmacist or doctor before using it, and avoid it if you are pregnant or breastfeeding.

Artemisia absinthium · Asteraceae · Leaves, flowering tops, and essential oil · Tea, tincture, capsules, extracts, essential oil

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

Wormwood: dosing

There is no well-established standard dose of wormwood, and safe amounts depend on the form and how much thujone it contains. It is usually used only for short periods.If you choose to use a wormwood product, follow the directions on the label and choose a reputable brand. Do not exceed the recommended amount, avoid long-term use, and never take the concentrated essential oil by mouth.

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

Read the full Wormwood 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 & Wormwood

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

0Major
50Moderate
0Minor
2,779No known interaction
50 Moderate 2,779 No interaction
Moderate

50 interactions

No interaction 2,779 drugs checked — show the list

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

Showing the 60 most looked-up of 2,779 medications checked with no known interaction — see the full Wormwood list.

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

Wormwood References

The 10 references that drive our Wormwood 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. Weisbord SD, Soule JB, Kimmel PL. Poison on line-acute renal failure caused by oil of wormwood purchased through the internet. N Engl J Med 1997;337:825-7. PubMed
  2. Gambelunghe C, Melai P. Absinthe: enjoying a new popularity among young people? Forensic Sci Int 2002;130:183-6.
  3. Hold KM, Sirisoma NS, Casida JE. Detoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo. Chem Res Toxicol 2001;14:589-95.
  4. Lachenmeier DW, Walch SG, Padosch SA, Kroner LU. Absinthe--a review. Crit Rev Food Sci Nutr 2006;46:365-77.
  5. Padosch SA, Lachenmeier DW, Kroner LU. Absinthism: a fictitious 19th century syndrome with present impact. Subst Abuse Treat Prev Policy 2006;1:14. PubMed
  6. Lachenmeier DW, Emmert J, Kuballa T, Sartor G. Thujone--cause of absinthism? Forensic Sci Int 2006;158:1-8. PubMed
  7. Dettling, A., Grass, H., Schuff, A., Skopp, G., Strohbeck-Kuehner, P., and Haffner, H. T. Absinthe: attention performance and mood under the influence of thujone. J Stud.Alcohol 2004;65(5):573-581. PubMed
  8. Benezet-Mazuecos, J. and de la Fuente, A. Electrocardiographic findings after acute absinthe intoxication. Int J Cardiol. 11-10-2006;113(2):e48-e50. PubMed
  9. El Makrini NI, Hassam B. Artemisia absinthium: burning plant! Pan Afr Med J. 2016 Jan 22;23:10. PubMed
  10. Kocaoglu C, Ozel A. Persistent metabolic acidosis and severe diarrhoea due to Artemisia absinthium poisoning. J Pak Med Assoc. 2014 Sep;64(9):1081-3.

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 Wormwood and Valacyclovir Together: Common Questions

Is it safe to take Wormwood with Valacyclovir?
We do not list a known interaction between Wormwood 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.
Do Wormwood and Valacyclovir have any of the same side effects?
Yes — our sources link each of them separately to 7 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 Wormwood and Valacyclovir combination checked?
Interactions in our licensed database are recorded against drug classes. Valacyclovir is filed under 3 classifications, and Wormwood has documented interactions with 1 drug class — 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 Wormwood interact with any other medications?
Yes. Wormwood has 50 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 — Wormwood 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

Wormwood 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 10 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Valacyclovir and Wormwood?

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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.