Drug & supplement interaction

Dimethylsulfoxide (dmso) + Mechlorethamine Hydrochloride

Mechlorethamine Hydrochloride brand name: Valchlor.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Dimethylsulfoxide (dmso) has a moderate interaction with Mechlorethamine Hydrochloride. Topical DMSO might increase the effects and adverse effects of topical drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Dimethylsulfoxide (dmso) and Mechlorethamine Hydrochloride

Here is the interaction we found between these two, with the evidence behind it.

Moderate

TOPICAL DRUGS

Why this applies to Mechlorethamine Hydrochloride

Mechlorethamine Hydrochloride falls under TOPICAL DRUGS — the group Dimethylsulfoxide (dmso) interacts with.

Topical DMSO might increase the effects and adverse effects of topical drugs.
Evidence from animal studies and limited human studies suggests that DMSO may potentiate the action of numerous topical medications by increasing their absorption through the skin. This increase in absorption seems to depend on the concentration of DMSO and the molecular weight of the medication.
Severity Moderate Likelihood Possible Evidence B

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the key thing with Valchlor (mechlorethamine) gel: you rub it right onto your skin, and DMSO is known for one trick in particular, it helps other substances soak through the skin faster. So if DMSO ends up on the same patch of skin, it could push more of the mechlorethamine into your tissue than intended.

Why that matters: mechlorethamine is a strong chemotherapy agent, and its most common problems are right where you apply it, things like redness, itching, burning, blistering, and skin irritation. More absorption could mean more of that local reaction. This concern comes mostly from animal work and limited human data, so it's not certain, but it's reasonable to be cautious. Don't change anything on your own simply check with your oncologist or pharmacist before pairing these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Jacob SW, Herschler R. Pharmacology of DMSO. Cryobiology 1986;23:14-27. PubMed
  2. Capriotti K, Capriotti JA. Dimethyl sulfoxide: history, chemistry, and clinical utility in dermatology. J Clin Aesthet Dermatol. 2012;5(9):24-6.
  3. DOMOSO SOLUTION (90% Dimethyl Sulfoxide). Fort Dodge Animal Health, Fort Dodge, Iowa. Avaliable at: https://www.zoetisus.com/_locale-assets/mcm-portal-assets/products/pdf/domoso_solution_pi.pdf. Accessed 8/3/2020.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Dimethylsulfoxide (dmso) Also Interacts With Other Medications

Dimethylsulfoxide (dmso) has 338 moderate known drug interactions in our database — the Mechlorethamine Hydrochloride one above is one of them. If you take anything else, check it against the full list below.

Moderate 338 No known interaction 2,492 (incl. Mechlorethamine Hydrochloride)
Taking anything else?

Check Another of Your Medications Against Dimethylsulfoxide (dmso)

Covers the 2,830 medications we’ve checked against Dimethylsulfoxide (dmso). Pick one to open its full report.

From our Q&A

Questions About Dimethylsulfoxide (dmso) or Mechlorethamine Hydrochloride

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Dimethylsulfoxide (dmso) or Mechlorethamine Hydrochloride, 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 Mechlorethamine Hydrochloride

This page covers Dimethylsulfoxide (dmso) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Mechlorethamine Hydrochloride page lists 10 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Acerola (moderate), Alpha-lipoic Acid (moderate), Coenzyme Q10 (moderate), Rose Hip (moderate) and Turmeric (moderate).

By severity: 9 moderate · 1 minor.

From our pharmacist’s overview on the Mechlorethamine Hydrochloride page

“Mechlorethamine (Valchlor) is a chemotherapy gel applied to the skin for a form of lymphoma, and the 10 supplements on this page split into two groups. Seven are antioxidants, everyday products like vitamin C and turmeric, which in theory could blunt how well an alkylating chemotherapy drug works.”

Reviewed by 2 · Jul 18, 2026

Open the Mechlorethamine Hydrochloride interaction page

How much people look this up

Where Dimethylsulfoxide (dmso) and Mechlorethamine Hydrochloride 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 Dimethylsulfoxide (dmso)
Top half

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

29 days ago today
Medication Mechlorethamine Hydrochloride
Steady interest

#1,502 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.

Supplement

About Dimethylsulfoxide (dmso)

What is Dimethylsulfoxide (dmso)?

Dimethylsulfoxide (dmso)
  • Muscle and joint pain
  • Arthritis
  • Sprains and strains
  • Interstitial cystitis (bladder pain)
  • Skin penetration enhancer for other medicines

DMSO is a colorless liquid solvent that people apply to the skin for pain and inflammation, and it is FDA-approved (as a prescription) only for interstitial cystitis placed directly into the bladder. Most over-the-counter uses for pain and arthritis have limited or low-quality evidence, and DMSO can carry impurities or push other chemicals through your skin. Talk to your pharmacist or doctor before using it, and avoid industrial-grade products.

Read the full Dimethylsulfoxide (dmso) monograph & all interactions
Medication

About Mechlorethamine Topical

What Is Mechlorethamine Topical Used For?

Brand name: Valchlor

Valchlor (mechlorethamine gel applied to the skin) is approved to treat Stage IA and IB mycosis fungoides-type cutaneous T-cell lymphoma — a slow-growing cancer that primarily affects the skin. It is used in patients who have already received at least one prior skin-directed treatment.

See full Mechlorethamine Topical drug information
Keep checking

Other Drugs & Dimethylsulfoxide (dmso)

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

0Major
338Moderate
0Minor
2,491No known interaction
338 Moderate 2,491 No interaction
Moderate

338 interactions

Showing 60 of 338 moderate interactions — see all 338 on the Dimethylsulfoxide (dmso) page.

No interaction 2,491 drugs checked — show the list

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

Showing the 60 most looked-up of 2,491 medications checked with no known interaction — see the full Dimethylsulfoxide (dmso) list.

See the full Dimethylsulfoxide (dmso) interactions page
See every supplement checked against Mechlorethamine Hydrochloride, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Dimethylsulfoxide (dmso) monograph › Uses, safety, and every drug interaction in one place Mechlorethamine Hydrochloride supplement interactions › Every supplement checked against Mechlorethamine Hydrochloride, ranked by severity Mechlorethamine Topical drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Dimethylsulfoxide (dmso) and Mechlorethamine Hydrochloride Together: Common Questions

Can you take Dimethylsulfoxide (dmso) with Mechlorethamine Hydrochloride?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Dimethylsulfoxide (dmso) and Mechlorethamine Hydrochloride interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Mechlorethamine Hydrochloride and Dimethylsulfoxide (dmso)?

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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.