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Depo-Medrol (methylprednisolone) withdrawal and detection times for horses

Depo-Medrol (methylprednisolone) is a corticosteroid, also sold as Methylprednisolone Acetate, Depo-Medrol, Methylprednisolone Sodium Succinate, Solu-Medrol. Below: how 6 show and racing governing bodies list it, every published detection time for the dose and route studied, and the document and page each value comes from.USEF: Permitted with conditionsFEI: Controlled Medication, detection time 672 h (28 days)HISA: Controlled medicationnamed in the rules of 19 state racing commissions

Published detection times for Depo-Medrol

Each row is one study the governing body published: its own dose, route and formulation. A different dose or route was not studied, and the body says so.

Body and documentDose and route studiedFormulationHorsesDetection time
USEF (US Equestrian)
2026 (last revised 1 Dec 2025; amendments effect… p. 11
dose not stated in the row336 h (14 days)
plasma / urine
FEI
2024 (16 December 2024) p. 2
200mg in 3 joints · intra-articularDepomedrol5672 h (28 days)
FEI
2024 (16 December 2024) p. 2
100mg in 2 joints · intra-articularDepomedrol5336 h (14 days)
Equestrian Canada
Rev. January 15, 2025 p. 18
200mg IA · intra-articular336 h (14 days)
Equestrian Canada
Rev. January 15, 2025 p. 18
100mg IA · intra-articular144 h (6 days)

How each rulebook lists Depo-Medrol

Transcribed from the governing bodies' own documents. Each entry links to the document and quotes the row it came from.

USEF (US Equestrian)

2026 USEF Guidelines & Rules for Drugs and Medications (with 27 Jul 2026 Guidelines Update) p. 9 · 2026 (last revised 1 Dec 2025; amendments effective 27 Jul 2026, published 10 Aug 2026)
Permitted with conditions
  • Listed as: Potentially Permitted with Medication Report Form (MRF) according to GR411 · Timing: not within 24 h (1 day) of competition · Medication report form: required
  • Listed as: How Long Drugs Remain Detectable · Detection time: 336 h (14 days) for the dose studied · Medication report form: required
“Potentially Permitted with Medication Report Form (MRF) according to GR411: ... methylprednisolone (DepoMedrol®)” — source p. 9

FEI

2026 Equine Prohibited Substances List p. 25 · 2026 (effective 1 January 2026)
Controlled medication
  • Listed as: Controlled Medication
“CONTROLLED Methylprednisolone Corticosteroid (Methylprednisolone acetate)” — source p. 25
FEI List of Detection Times p. 2 · 2024 (16 December 2024)
Controlled medication
  • Listed as: Controlled Medication · Detection time: 672 h (28 days) for 200mg in 3 joints · Routes: intra-articular
  • Listed as: Controlled Medication · Detection time: 336 h (14 days) for 100mg in 2 joints · Routes: intra-articular
“METHYLPREDNISOLONE Depomedrol 200mg in 3 joints i.a. 5 672 (28d)” — source p. 2

From 2027-01-01: 2027 Equine Prohibited Substances List p. 26 lists it as Controlled Medication.

Equestrian Canada

Controlled medication
  • Listed as: Prohibited substance
  • Listed as: Prohibited substance · Detection time: 144 h (6 days) for 100mg IA · Routes: intra-articular
  • Listed as: Prohibited substance · Detection time: 336 h (14 days) for 200mg IA · Routes: intra-articular
“Methylprednisolone” — source p. 11

NCHA

2026 NCHA Rule Book - Standing Rule 35A, Medication and Drug Rules and Guidelines p. 14 · 2026 Rule Book, SR 35A extract (pages 75-95; PDF created 30 Jun 2026)
Permitted with conditions
  • Listed as: Prohibited substance exception: therapeutic corticosteroid (35A.10.g.iii) · Maximum dose: 300 mg maximum total dosage · Timing: not within 24 h (1 day) of competition · Medication report form: required
“4. Methylprednisolone – 300 mg.” — source p. 14

HISA / HIWU

HISA Prohibited Substances List: Controlled Medications p. 19 · Last updated on December 8th, 2023
Controlled medication
  • Listed as: S7 Controlled Medication Substances
“Methylprednisolone ... Corticosteroid” — source p. 19

ARCI

Controlled medication
  • Listed as: Class 4, Penalty C
“Methylprednisolone Medrol 4 C” — source p. 39
ARCI Controlled Therapeutic Medication Schedule for Horses p. 5 · Version 4.2.1 (Revised December 2020); policies from Model Rules Version 15 (August 2026)
Permitted up to a threshold
  • Listed as: Controlled Therapeutic Medication · Dose in the rule: 100 milligram dose in one articular space · Screening limit: 100 picograms per milliliter of plasma or serum · Routes: intra-articular
“Methylprednisolone | 100 picograms per milliliter of plasma or serum | The recommended withdrawal for methylprednisolone acetate is a minimum of 21 days at a 100 milligram dose” — source p. 5

State racing commissions

Depo-Medrol is named in the medication rules, threshold schedules or withdrawal guidance of 19 state racing commissions: Arizona, Colorado, Florida, Illinois, Indiana, Kentucky, Louisiana, Maine, Maryland, Minnesota, Nebraska, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Texas, Washington, West Virginia. Most states publish thresholds (concentrations), not times, and several adopt the ARCI schedule by reference. ShowSafe Pro Racing layers each state's rules over HISA or ARCI the way that state applies them, for all 32 states with live pari-mutuel racing.

Detection time is not withdrawal time

A published detection time tells you how long Depo-Medrol stayed detectable in a handful of horses given one dose by one route. It does not tell you when your horse is clear: a bigger dose, a different route, repeated doses, a joint injection or a slower horse all push the real figure out, and every governing body says to add a safety margin set by your veterinarian. Here is how to read the rulebook.

ShowSafe Pro takes the doses already logged for your horse, matches each one to the published row for that dose and route, adds the margin your vet set, and flags anything the studies never covered as Unknown, ask your vet instead of guessing. Every answer shows the document, page and line it came from, for every rulebook the show runs under.

A detection time is the approximate period a drug or its metabolite stayed detectable in the horses studied, at the dose and route studied. It is not a withdrawal time. No governing body publishes withdrawal times for you; your veterinarian sets the safety margin for your horse. Nothing on this page is a veterinary ruling or a promise that a horse will test clean. Rules change; the document, version and page behind every value are linked so you can check the current text.

Questions about Depo-Medrol

Is Depo-Medrol allowed at USEF shows?

The 2026 USEF Guidelines & Rules for Drugs and Medications (with 27 Jul 2026 Guidelines Update) list Depo-Medrol as "Potentially Permitted with Medication Report Form (MRF) according to GR411". Not within 24 h (1 day) of competition. (Page 9.)

What is the FEI detection time for Depo-Medrol?

The FEI List of Detection Times gives 672 h (28 days) for 200mg in 3 joints intra-articular (Depomedrol); 336 h (14 days) for 100mg in 2 joints intra-articular (Depomedrol). On the 2026 FEI Equine Prohibited Substances List Depo-Medrol is a Controlled Medication. The FEI states that a detection time is not a withdrawal time; the treating veterinarian adds a safety margin.

Does a published detection time mean my horse will test clean?

No. It is the approximate time Depo-Medrol stayed detectable in the horses studied, at that dose and route. Your horse, dose, route and number of doses may differ. Every governing body tells you to add a safety margin set by your veterinarian, and none publishes a withdrawal time. ShowSafe Pro applies the published row for the dose and route you actually gave, adds your vet's margin, and says 'Unknown' when the studies do not cover what you gave.

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