CureFIP™ GS-441524 + B12 Injectable 20mg/ml
Antiviral Treatment With Integrated Cobalamin Support for Small Cats and Kittens
What This Product Is
CureFIP™ GS-441524 + B12 20mg/ml is a combined antiviral and nutritional support formulation containing GS-441524 at 20mg/ml and cyanocobalamin (Vitamin B12) at 50mcg/ml in a single injectable solution. It is designed for FIP treatment in cats weighing under 2.5 kg where secondary systemic complications — anaemia, neurological involvement, appetite suppression, or immune compromise — are present alongside the primary FIP diagnosis.
The antiviral component is identical to the standard CureFIP™ GS-441524 20mg/ml formulation. The addition of B12 does not alter GS-441524 concentration, dosing calculation, or antiviral mechanism. It adds a clinically meaningful layer of systemic support delivered through the same injection, eliminating the need for a separate B12 administration.
Why This Concentration: The Small Cat Precision Argument
In cats under 2.5 kg, high-concentration formulations produce injection volumes too small for reliable measurement. The 20mg/ml format ensures the daily GS-441524 dose can be drawn and administered accurately. This is the foundational reason for the 20mg/ml concentration — see the standard 20mg/ml product page for the full dosing precision rationale.
Why B12 Has Been Added
FIP is a systemic viral disease. By the time most cats are diagnosed, the feline infectious peritonitis virus (FIPV) has produced widespread inflammatory damage across multiple organ systems. The antiviral activity of GS-441524 addresses viral replication directly — but it does not immediately reverse the systemic damage already in progress. Many cats, particularly small cats and kittens whose physiological reserves are limited, present with one or more of the following secondary complications at diagnosis:
Anaemia FIPV-associated inflammation suppresses erythropoiesis — the production of red blood cells. Anaemic cats are lethargic, cold-intolerant, and have compromised oxygen delivery to tissues. Cobalamin is an essential cofactor in red blood cell synthesis. B12 at 50mcg/ml supports haematopoietic recovery alongside viral clearance.
Neurological involvement Dry (non-effusive) FIP and neurological FIP presentations involve central nervous system inflammation. Myelin sheath integrity — critical for nerve signal transmission — is partially B12-dependent. Cobalamin supplementation contributes to neurological recovery in affected cats, complementing the antiviral suppression of the underlying viral cause.
Appetite suppression and weight loss FIP cats frequently present with significant appetite loss, accelerating weight decline that is particularly dangerous in cats already under 2.5 kg. Cobalamin has a well-documented role in appetite pathway activation. B12 administration commonly produces observable improvements in appetite within the first days of treatment, supporting the nutritional intake necessary for recovery.
Immune system compromise Cobalamin is a cofactor in multiple immune system processes including lymphocyte proliferation. FIP-associated immune dysfunction is partially addressable through B12 supplementation alongside antiviral therapy.
Gastrointestinal dysfunction Some FIP presentations include GI involvement affecting nutrient absorption. B12 supports intestinal mucosal integrity and is itself absorbed through the GI tract — the injectable route in this formulation bypasses any absorption compromise entirely.
What B12 at 50mcg/ml Means Clinically
The 50mcg/ml concentration is formulated as adjunctive support — a clinically meaningful supplement dose delivered through the existing daily antiviral injection. It is not intended as a standalone therapeutic dose for severe B12 deficiency, which would require separate supplementation at different intervals and doses under veterinary guidance. If your cat has been diagnosed with primary B12 deficiency requiring therapeutic dosing, maintain the separate B12 protocol as directed by your veterinarian and inform our clinical team.
Indicated Cases
This formulation is most appropriate for:
- Kittens and small adult cats under 2.5 kg with FIP and confirmed or suspected anaemia
- Neurological FIP presentations in the small cat weight range
- Cats presenting with significant appetite loss or weight decline at diagnosis
- Cases where the owner or attending veterinarian wishes to consolidate antiviral and nutritional support into a single daily injection
- Cats with a history of B12-responsive conditions alongside a new FIP diagnosis
This Formulation Is Not the First Choice For
- Cats requiring therapeutic-dose B12 supplementation independently — maintain a separate B12 protocol as directed
- Cats over 2.5 kg — consider the 30mg/ml + B12 or 40mg/ml + B12 formulations
- Cases where the veterinarian has specifically indicated the non-B12 formulation
Concentration Selection Guide
| Concentration | Primary Indication |
|---|---|
| 20mg/ml + B12 (this product) | Cats under 2.5 kg with anaemia, neurological symptoms, or appetite loss |
| 20mg/ml | Cats under 2.5 kg · Standard antiviral only |
| 30mg/ml + B12 | Cats 2.5–5 kg with secondary systemic complications |
| 40mg/ml + B12 | Cats over 5 kg, high-dose protocol with systemic support needs |
Administration
Administer subcutaneously once daily. Dose is calculated in mg of GS-441524 per kg of body weight — the B12 component does not alter the dose calculation. Standard treatment duration is 84 consecutive days. Use the dosing calculator to determine the correct volume for your cat's current weight. Do not adjust dose without veterinary guidance.
GS-441524 Antiviral with Vitamin B12 | 20mg/ml
Chemical Formula: C12 H13 N5 O4
Concentration: 20mg/ml
Quantity: 1 vial
Purity: 99.4%
pH: 2.2Formulation: 5% ethanol, 30% propylene glycol, 45% PEG 400, 20% water.
Shelf Life: 1 Year, Vials must be stored at ROOM TEMPERATURE. Do not store the vials in the freezer or the cooler or temperature below 8 degree celsius or 46 degree Fahrenheit, which may result in precipitation of API or crystallization of API.
Reviews
We had 2 litter of kittens develop FIP within a month of each other. We are treating 4 kittens, 2 with wet FIP, 1 with dry and one occular.
We started the first two with and the 4th with injections. Custard has wet and her fluid started to reabsorb after 5 days of injections.
Custard and Siren (sisters) started having more energy and were playful kittens after a couple weeks. We switched to the pills after 45 days of injections.
This medicine saved their lives!
Bruiser Himalayan was born on 8/18/2023. Diagnosed in February with FIP. Started injection on March 2, 2024 and saw immediate results in energy. Cat weight was 4.5 pounds at start. Started eating well and was more and more like a normal cat. Switched to pills because he was fighting the shots. He now weighs 8.6 pounds, run, climbs, attacks us playfully. On the pills I separated the capsule and mixed contents in a Churu and the cat loved eating it. Glad the new vet had me go to CUREFIP.COM
We were shocked at the change in our kitten within just a few doses. We have been using for approx 4 weeks and the change is nothing short of amazing.
By law the Vets cannot prescribe this as it is not FDA approved. On discharge a staff girl gave a paper telling about this product legally available from Compound pharmacies. Upon doing extensive web research I decided to try CureFIPUSA. These are excellent products as the cat (a Chocolate Oriental) which had wet FIP, responded within a few days. She is doing great after 28 shots and continues to gain weight. Glad I chose CUREFIPUSA. Info on this site will guide you thru complete treatment.
We found our cat, Lucky, wandering on the streets, a month ago. He was heavily malnourished and diagnosed with FIP. The vet told us to put it to sleep, but we did our research and found about curefipusa. We ordered the injection and have been treating our cat for three weeks with great results. The cat is eating, active and has gained weight. Thank you for it curefipusa.