Phenibut Banned in USEF Competitions 🐴

When it comes to competitive horses, supplements marketed as “calming aids” are popular—but not always safe or allowed. One example is Phenibut, now banned by the United States Equestrian Federation (USEF). I’m Dr Duncan Houston BVSc, and here’s what equestrians need to know in 2025 about Phenibut and behavior-altering supplements ⚠️

🔬 What Is Phenibut?

Phenibut is a synthetic chemical structurally related to the brain chemical GABA (gamma-aminobutyric acid). It has anti-anxiety effects in humans but is not an approved veterinary drug. It has been found in equine calming products like Focus Calm.

⚠️ Why Phenibut Is Banned

Phenibut is listed by the USEF as a forbidden foreign substance. It is not the same as phenylbutazone (“bute”)—despite the similar name. There are no safety studies supporting its use in horses, and no legitimate therapeutic reason for its inclusion in supplements.

📋 USEF Position

• 🚫 Phenibut is considered a banned calming agent
• 📜 It is not recognized as a veterinary medication
• ⚖️ Presence in a horse's system at competition can result in disqualification

🔍 Hidden Risks in Supplements

The equine supplement market is largely unregulated, and calming products may contain substances not listed—or listed under misleading names. Even if Phenibut or other substances are not on the label, they may still be present. This puts owners and horses at risk.

🐴 Potential Dangers of Unapproved Calming Agents

• ⚠️ Sedation or neurologic side effects
• ⚠️ Behavioral disorientation
• ⚠️ Masking pain or stress-related illness

🧠 Bottom Line for Owners

• ✅ Always check with your vet before using any calming supplement
• ✅ Only use products with full ingredient disclosure
• ❌ Avoid supplements with vague claims or non-veterinary substances
• ✅ Review USEF’s Drug and Medications Guidelines regularly

📲 Need Help Evaluating a Supplement?

If you’re unsure whether a supplement is USEF-safe or appropriate for your horse’s behavior, use the Ask A Vet app to chat directly with a licensed veterinarian 🐴💬

✅ Summary

• 🚫 Phenibut is banned in USEF competitions
• ⚠️ Found in calming products like Focus Calm
• 🔍 May be unlisted or disguised on labels
• 💉 Not proven safe for horses—use extreme caution
• 🧪 Disqualification is possible if detected

Stay informed, stay compliant—and protect your horse’s safety and show record 🏅

— Dr Duncan Houston BVSc