Equine Sports Council

Controlled Medications Library

ESC MEDICATION CLASSIFICATIONClass A - Therapeutic

ESC Medication Library · Revision 3

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Dimethylsulfoxide,

Medication Facts

Performance enhancing
No
Total hours to clear
Not recorded
Frequently used
Most Prescribed
ESC ID
DIMETH-0305
Trade names
DMSO
Drug type
Solvent/Anti-inflammatory
Plasma half-life · hours
9 to 14 hrs
Equine dosing
1-2 g/kg IV/Topical
Cmax · peak plasma concentration
8.11 mg/mL
Tmax · time to peak plasma concentration
15 minutes
ESC concentration guidance
50 to 130 micrograms/mL (130,000 nanograms/mL)
Primary withdrawal · hours
0
Washout withdrawal · hours
0
ESC control type
A1 - Generally Controlled - Therapeutic
Medication report required
Generally not required, however understand exceptions.

Uses & side effects

Drug interactions

DMSO's primary drug interaction risk stems from its role as a potent solvent and carrier; it significantly enhances the absorption of other substances through biological membranes, DMSO has anti-cholinesterase activity. It must never be used within several days of cholinesterase-inhibiting pesticides, fly sprays, or certain worming preparations.has anti-cholinesterase activity. which can inadvertently lead to toxicity or intensified drug effects. DMSO should not be used with corticosteroids such as Dexamethasone, certian NSAIDS, certian sedatives and anesthetics. Combinations are considered performance enhancing and could put your horse's health at risk.

Contraindications

Surpass

Government Numbers

Domoso Gel: NADA 047-925. Manufacturer-hosted label lists NDC 0856-0046-50 (60 g tube) and 0856-0046-51 (120 g tube). These are identifiers printed on this label; current commercial availability has not been established. This gel is labeled for topical use only. Reviewed September 18, 2026. https://www.zoetisus.com/content/_assets/docs/domoso_gel_pi.pdf

Sanctioning-body comparison

Plasma only. Compare published competition guidance for this medication. ESC guidance remains in Medication Facts above. A dosing guideline, withdrawal recommendation and laboratory detection threshold are different measures.

Sources reviewed September 23, 2026. “Not verified” means a gap in this comparison, not zero tolerance or permission. Doses describe the cited rules; your veterinarian must determine treatment and withdrawal.

Published guidance by organization
OrganizationPublished dose & routePlasma concentrationWithdrawal / timingControl / penalty class
AQHA Show HorsesShow rules · 2026 handbook
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules.

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Medication-specific control not yet verified.
APHA Paint Show HorsesShow rules · 2026 Rule Book
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules.

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Medication-specific control not yet verified.
ARCI Model RulesRacing model · Rules 15 / UCG 20.0 / CTMS 4.2.1
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules. ARCI model comparison only; no state-specific rule is substituted. Schedule timing is tied to its stated regimen and is not a clearance guarantee.

UCG 20.0 PDF p. 25

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Drug Class 4 · Penalty Class C. No dosing permission is implied by classification.
USEFNational Therapeutic Substance Provisions · 2026 + July amendment
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules.

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Medication-specific control not yet verified.