Equine Sports Council

Controlled Medications Library

ESC MEDICATION CLASSIFICATIONClass A - Therapeutic

ESC Medication Library · Revision 3

← Medication library · Compare sanctioning bodies

Regumate,
Altrenogest

Med ReportRecommended

Medication Facts

Performance enhancing
No
Total hours to clear
48
Frequently used
Most Prescribed
ESC ID
REGUMA-0787
Trade names
Regumate
Drug type
Progestin
Plasma half-life · hours
10 hrs
Equine dosing
0.044 mg/kg PO daily, may not exceed single dose amounts. **permitted use in mares, geldings, studs**
Cmax · peak plasma concentration
50 ng/mL
Tmax · time to peak plasma concentration
72
ESC concentration guidance
CMAX 50 ng/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

Synthetic hormone supresses mare heat cycles

Drug interactions

Contraindications

Government Numbers

Regu-Mate altrenogest oral solution, 2.2 mg/mL (0.22%): NADA 131-310; NDC 57926-100-70 (1,000 mL). Labeler: Merck Sharp & Dohme Corp. Identifiers apply to this oral formulation. Reviewed September 18, 2026. Full label, including user handling warnings: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d9d14df1-ec72-46f1-ad3b-f90547088ff5

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. Classification for geldings, colts, adult intact males, spayed females only. 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. 12

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

GR410.2; altrenogest guidance

Reviewed 2026-09-23

 No competition dose specified in the cited rule.No numeric plasma threshold stated.No withdrawal specified for the permitted mare use.Permitted in mares; prohibited in stallions and geldings.