GS-441524

GS-441524 is an experimental antiviral compound that has gained attention primarily for its use in treating Feline Infectious Peritonitis (FIP), a previously fatal disease in cats caused by a mutated form of feline coronavirus (FCoV). GS-441524 is a nucleoside analog, and it is the active metabolite of remdesivir, which was developed by Gilead Sciences.

 What Is GS-441524?

• Drug Class: Antiviral nucleoside analog

• Mechanism of Action: Inhibits viral RNA polymerase, preventing viral replication

• Primary Use: Off-label treatment of FIP in cats

• Origin: Investigational compound developed during research on Ebola and SARS-CoV-2

 Clinical Use in Cats

Although not officially approved by the FDA or EMA for veterinary use, GS-441524 has been widely used internationally to treat FIP. Its use became more widespread following research published by Dr. Niels Pedersen (UC Davis), which demonstrated an over 80% success rate in treating cats with both the effusive and non-effusive forms of FIP.

 Forms Available:

• Injectable solution (usually 15–30 mg/mL)

• Oral tablets or liquid suspensions

• Research-grade powder (for compounding)

 Treatment Protocols for FIP:

• Duration: 84 days (12 weeks) is the standard protocol

• Dosage: Depends on cat’s weight and FIP type (ocular, neurological forms require higher doses)

• Monitoring: Regular bloodwork and vet checkups throughout treatment

  Legal and Safety Notes:

• GS-441524 is not commercially licensed, meaning most access is through gray-market sources or compounding pharmacies in select countries.

• Remdesivir (a related, FDA-approved drug) is sometimes used off-label in veterinary settings as an alternative.

• Always consult a licensed veterinarian experienced with FIP treatment before beginning a course of GS-441524.

 Where to Buy:

Reputable sources include:

• Stokes Pharmacy (USA) – compounded under prescription

• Avrio Pharmacy

• CURE FIP USA

• Cat2FIP.co (Europe)

• Chinese manufacturers (caution advised; quality varies)