Methylsulfonylmethane (msm) + Valacyclovir
Valacyclovir brand name: Valtrex.
We found no known interaction between Methylsulfonylmethane (msm) 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.
Methylsulfonylmethane (msm) 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 Methylsulfonylmethane (msm) 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 Methylsulfonylmethane (msm) at all — not against Valacyclovir, 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.
Methylsulfonylmethane (msm) safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Questions About Methylsulfonylmethane (msm) 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 Methylsulfonylmethane (msm) 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:
- Provitalize With Levothyroxine, Valacyclovir, and Citalopram ›
- Is Valacyclovir Safe To Take With Acetaminophen And Guaifenesin? ›
- Alternatives To Valtrex For The Treatment Of Herpes ›
Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.
See Every Supplement That Interacts With Valacyclovir
This page covers Methylsulfonylmethane (msm) 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
Where Methylsulfonylmethane (msm) 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.
#713 of 1,452 supplements looked up here in the last 7 days
#31 of 2,830 medications looked up here in the last 7 days
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 Methylsulfonylmethane (msm) reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Methylsulfonylmethane (msm) and Valacyclovir 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.
About Methylsulfonylmethane (msm)
What is Methylsulfonylmethane (msm)?
- Osteoarthritis and joint pain
- Muscle soreness after exercise
- Inflammation
- Skin and hair health
- Allergy symptoms
Methylsulfonylmethane (MSM) is a natural sulfur compound that people most often take for joint pain and exercise recovery. Some early research suggests it may modestly help osteoarthritis symptoms, but the evidence is limited and more study is needed. It appears generally well tolerated in the short term, but talk with your pharmacist or doctor before starting it.
Not applicable (a sulfur-containing compound) · Capsules, tablets, powders, creams, and combination joint supplements
An interaction check asks whether these two react with each other — it does not ask whether Methylsulfonylmethane (msm) is a good idea for someone in your situation. Here is what our Methylsulfonylmethane (msm) record says about it on its own.
Methylsulfonylmethane (msm): dosing
There is no official or standardized dose of MSM. Studies have used a wide range of amounts, and the best dose is not clearly established.The safest approach is to follow the directions on the product label and not take more than recommended. They can help you decide if it is appropriate and what amount is reasonable.
From our Methylsulfonylmethane (msm) monograph — the full record covers uses, side effects and every documented interaction.
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.
Other Drugs & Methylsulfonylmethane (msm)
Browse every other medication we’ve checked against Methylsulfonylmethane (msm) — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
No interaction 2,829 drugs checked — show the list
We also checked Methylsulfonylmethane (msm) against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Metoprolol ›
- Aspirin ›
- Ivermectin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Acetaminophen ›
- Tadalafil ›
- Clopidogrel ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Abemaciclib ›
- Methamphetamine ›
- Ibuprofen ›
- Sumatriptan ›
- Semaglutide ›
- Tirzepatide ›
- Warfarin Sodium ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Bupropion ›
- Metformin ›
- Acyclovir ›
- Amoxicillin ›
- Lisinopril ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Methotrexate ›
- Lamotrigine ›
- Fluoxetine ›
- Amphetamine ›
- Pregabalin ›
- Gabapentin ›
- Acetaminophen, Codeine ›
- Azithromycin ›
- Dextroamphetamine ›
- Isotretinoin ›
- Clonazepam ›
- Omeprazole ›
- Quetiapine ›
- Methylene Blue ›
- Amlodipine Besylate ›
- Duloxetine ›
- Letrozole ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
- Naproxen ›
- Bisoprolol ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Methylsulfonylmethane (msm) list.
Methylsulfonylmethane (msm) References
The 4 references that drive our Methylsulfonylmethane (msm) 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.
- Barrager E, Veltmann JR Jr, Schauss AG, Schiller RN. A multicentered, open-label trial on the safety and efficacy of methylsulfonylmethane in the treatment of seasonal allergic rhinitis. J Altern Complement Med 2002;8:167-73. PubMed
- Usha PR, Naidu MU. Randomised, Double-Blind, Parallel, Placebo-Controlled Study of Oral Glucosamine, Methylsulfonylmethane and their Combination in Osteoarthritis. Clin Drug Investig. 2004;24(6):353-63. PubMed
- Kim LS, Axelrod LJ, Howard P, et al. Efficacy of methylsulfonylmethane (MSM) in osteoarthritis pain of the knee: a pilot clinical trial. Osteoarthritis Cartilage 2006;14:286-94. PubMed
- Hwang JC, Khine KT, Lee JC, Boyer DS, Francis BA. Methyl-sulfonyl-methane (MSM)-induced acute angle closure. J Glaucoma. 2015 Apr-May;24(4):e28-30. 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.
Taking Methylsulfonylmethane (msm) and Valacyclovir Together: Common Questions
Is it safe to take Methylsulfonylmethane (msm) with Valacyclovir?
Do Methylsulfonylmethane (msm) and Valacyclovir have any of the same side effects?
Does Valacyclovir interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.