Recovery in 4 to 8 Weeks
87% Success Rate
Zero Injections, easy at home treatment
Substantially higher antiviral potency than Molnupiravir (EIDD-2801)
Rapid reduction of FCV replication
long-term management of calicivirus
Antiviral support for eye and respiratory flares of Feline Herpesvirus (FHV-1)
Powered by famciclovir
Zero injections, easy at-home tablets
Scientifically
Verified
"Our treatments are developed based on findings from internationally peer-reviewed research."
Professional
Treatment Advice
"Our treatment support team is technically trained to assist with treatment-related questions."
Fast
Delivery
“We operate local warehouses in the countries we serve, ensuring reliable and timely delivery for every order.”
No
Injections
“Our treatments are provided in soft gel capsules and are easy to administer at home, taken twice daily (12 hours apart).”
"EIDD-1931 is not suitable for all FIP conditions. Cats with neurologic and ocular FIP symptoms, appetite and digestive problems, and pre-existing kidney and liver diseases should start FIP treatment with GS-441524 injections for 2 - 4 weeks before switching to EIDD-1931."
FAQs
What is HerpX™ used for?
HerpX™ is an oral antiviral tablet (famciclovir 180 mg) for cats with Feline Herpesvirus (FHV-1). It is used under veterinary guidance to support cats through ocular and upper respiratory flares, including conjunctivitis and corneal disease, by reducing viral replication and shedding so flares settle faster.
How is HerpX™ different from CaliciX™ and MolnuFIP™?
They treat different viruses with different molecules. CaliciX™ and MolnuFIP™ use EIDD-1931 for Feline Calicivirus (FCV) and FIP. HerpX™ uses famciclovir, the antiviral most established for Feline Herpesvirus (FHV-1). If your cat's problem is the eyes and upper respiratory tract rather than oral disease, HerpX™ is the relevant product.
Does HerpX™ cure Feline Herpesvirus (FHV-1)?
No. Feline Herpesvirus (FHV-1) stays latent in the body for life, so no treatment removes it. HerpX™ is used to control active flares and protect the eyes, helping signs resolve more quickly. Most cats live normal, comfortable lives with good flare management.
Can HerpX™ help with my cat's eye problems?
The eyes are the hallmark of Feline Herpesvirus (FHV-1), and active ocular flares are exactly where prompt antiviral support matters most. HerpX™ reaches therapeutic levels in tears and is used for ocular flares, often alongside topical eye treatment chosen by your veterinarian. A squinting, cloudy, or ulcerated eye should be seen urgently.
Is famciclovir safe for cats?
Famciclovir is regarded as systemically well tolerated in cats when dosed correctly. This is an important distinction from acyclovir and valacyclovir, human antivirals that are toxic to cats and must never be used in their place. HerpX™ is made for feline use under veterinary supervision.