FIP Treatment FAQs – GS-441524 Questions Answered

Frequently Asked Questions

ABOUT FIP & GS-441524

FIP (Feline Infectious Peritonitis) is a serious, progressive disease caused by a mutation of the feline coronavirus. In most cats, feline coronavirus causes no symptoms or only mild digestive upset. In a small percentage of cases, the virus mutates into FIPV — triggering a damaging immune response that attacks blood vessel walls and organs throughout the body.

FIP presents in two main forms. Wet (effusive) FIP causes fluid accumulation in the abdomen or chest, producing visible swelling and breathing difficulty. Dry (non-effusive) FIP causes inflammatory lesions in organs such as the brain, eyes, kidneys, or liver, with a wider range of less obvious symptoms. Some cats develop both forms simultaneously or transition from one to the other.

Until recently, FIP was considered almost universally fatal. The development of antiviral treatments — particularly GS-441524 — has fundamentally changed this, with recovery rates above 80% in cats that complete the full treatment protocol.

FIP stands for Feline Infectious Peritonitis. The name reflects the early characterisation of the disease — "peritonitis" refers to inflammation of the peritoneum, the membrane lining the abdominal cavity, which was the most visually obvious sign in the wet (effusive) form. The name has remained even though the disease's full scope extends well beyond the abdomen, affecting the brain, eyes, kidneys, and other organs in its dry form.

GS-441524 is a nucleoside analogue antiviral compound that works by blocking the replication of the feline infectious peritonitis virus (FIPV). When the virus attempts to copy its RNA inside your cat's cells, GS-441524 interferes with that process — stopping the disease at its source rather than just managing symptoms.

It is the most extensively studied treatment for FIP, with clinical recovery rates consistently above 80% across multiple independent studies. Until recently, FIP was considered almost universally fatal. GS-441524 has changed that.

Across multiple independent clinical studies covering over 650 cats, the combined treatment success rate for GS-441524 is approximately 92%. Most cats that complete the full 84-day protocol reach sustained remission and return to a normal quality of life.

Cats that begin treatment earlier in the disease course tend to have the best outcomes. Complicated forms — including neurological and ocular FIP — have a lower but still meaningful recovery rate when treated at higher doses with injections. The key variables are: starting treatment promptly, dosing correctly by weight, and completing the full protocol without interruption.

Early symptoms common to both wet and dry FIP include persistent fever that does not respond to antibiotics, unexplained weight loss, loss of appetite, lethargy, and dull coat condition.

In wet FIP, additional signs include a visibly swollen or distended abdomen, laboured breathing (if fluid accumulates in the chest), and general weakness. In dry FIP, symptoms vary widely depending on which organs are affected — these can include neurological signs such as wobbling, tremors, or seizures; eye changes such as cloudiness, uneven pupil size, or inflammation; jaundice; or unexplained changes in behaviour.

If your cat is displaying any combination of these signs — particularly persistent fever alongside weight loss and lethargy — contact your veterinarian promptly. Early diagnosis significantly improves treatment outcomes.

FIP presents in two primary forms. Wet (effusive) FIP is characterised by fluid accumulation in the abdomen or chest cavity, and tends to progress rapidly. Dry (non-effusive) FIP involves inflammatory lesions in organs without significant fluid build-up, and typically progresses more slowly.

Both forms are treated with GS-441524 using the same core protocol. What changes is the starting dose and urgency of treatment. Neurological and ocular FIP — which can occur in either form — require higher doses and must be treated with injections only. If you are unsure which form your cat has, share your cat's diagnosis and bloodwork with our treatment team and we will advise on the correct protocol.

FIP develops when the feline enteric coronavirus (FCoV) — a common intestinal virus that most cats carry without ever falling ill — undergoes a mutation inside the cat's body. This mutation transforms it into the feline infectious peritonitis virus (FIPV), which triggers a severe immune response and attacks the cat's own tissues.

FCoV itself is contagious and spreads between cats through shared litter boxes, food and water bowls, and close contact — particularly in multi-cat households, shelters, and catteries. However, FIP itself does not spread directly from cat to cat. The mutation that causes FIP occurs randomly and cannot be predicted. Young cats under two years old, males, and purebred cats are at statistically higher risk of developing FIP after FCoV exposure.

This is one of the most common and understandably confusing questions from cat owners. FIP can develop in indoor cats because the feline coronavirus (FCoV) that causes it is extremely widespread — many cats are exposed in early life, particularly if they came from a breeder, cattery, shelter, or multi-cat household before joining your home.

FCoV can remain dormant in a cat's body for months or years before the random mutation event that triggers FIP. An indoor cat that has had no outside contact in years can still develop FIP from a coronavirus exposure that happened much earlier in its life. It is not a sign that anything went wrong in your care — the mutation is unpredictable and not preventable once FCoV exposure has occurred.

FIP itself is not directly transmitted between cats. What spreads between cats is the underlying feline coronavirus (FCoV), which in most cases causes no symptoms at all. The mutation that transforms FCoV into FIP occurs spontaneously inside an individual cat's body and cannot be passed on.

FCoV is shed in faeces and spreads through shared litter boxes, grooming, and close contact. Managing hygiene in multi-cat environments — particularly litter box cleanliness — is the primary way to limit FCoV circulation and reduce the overall risk of any individual cat developing FIP.

FIP itself is not directly contagious between cats. However, the underlying feline coronavirus (FCoV) that mutates into FIP is contagious and is commonly spread through shared litter boxes, food bowls, and close contact.

Most cats that carry FCoV never develop FIP — only a small percentage experience the viral mutation that causes the disease. During your cat's FIP treatment, standard hygiene precautions are sufficient: keep litter boxes clean, wash food and water bowls regularly, and monitor other cats in the household for any changes in behaviour, appetite, or weight. If another cat in your home develops symptoms, contact us promptly.

There is no single definitive test for FIP. Diagnosis typically involves a combination of approaches:

Blood tests are usually the starting point — looking at the albumin-to-globulin (A/G) ratio, white blood cell count, protein levels, and inflammatory markers. A low A/G ratio combined with clinical signs strongly suggests FIP. The Rivalta test can be performed on fluid from effusive cases and has high specificity for FIP. Immunofluorescence testing on fluid or tissue samples can detect the FIPV antigen directly. Advanced tools such as AGP testing and FIPV RT-PCR on effusion fluid provide greater certainty. In unclear cases, biopsy of affected tissue remains the most definitive method of confirmation.

If you suspect FIP, work with your veterinarian to build a diagnostic picture — no single result rules it in or out on its own.

There is currently no guaranteed method to prevent FIP, as the mutation from feline coronavirus to FIPV occurs unpredictably. However, the following measures reduce the risk of FCoV exposure and transmission:

Keep litter boxes clean and disinfect them regularly. Avoid overcrowding — FCoV spreads more readily in high-density cat environments such as shelters and multi-cat households. When introducing a new cat, isolate them initially and have them tested for FCoV before mixing with resident cats. Reducing environmental stressors, which are known to increase viral susceptibility, also plays a supporting role. A FIP vaccine exists in some markets but has shown limited effectiveness in clinical practice and is not widely recommended.

Without treatment, the prognosis for FIP is extremely poor. Wet FIP progresses rapidly — most untreated cats survive only days to a few weeks after symptoms appear. Dry FIP progresses more slowly, but remains fatal without antiviral intervention. The median survival time from diagnosis without treatment is approximately 9 days.

With GS-441524 treatment, the outlook has changed dramatically. The majority of cats that complete the full 84-day protocol reach sustained remission and go on to live normal, healthy lives. Treatment should begin as early as possible — delay reduces the likelihood of a full response, particularly in advanced or neurological cases. Contact our treatment team immediately if your cat has been diagnosed or you suspect FIP.

Yes. The majority of cats that complete a full course of GS-441524 treatment go on to live normal, healthy lives. In clinical studies, most cats in sustained remission after the 84-day protocol show no long-term health consequences from the infection itself.

Some cats experience residual effects from organ involvement during the active disease phase — particularly in cases with neurological or ocular complications — but these typically resolve or stabilise after treatment ends. Weight regained during treatment is usually maintained. Most owners report that their cats return fully to pre-FIP behaviour within weeks of completing the protocol.

Completing the 84-day protocol is the end of active treatment, not the end of monitoring. After your cat finishes the course, a 12-week observation period begins. During this period, your cat should not be on any antiviral medication. If no signs of FIP return during those 12 weeks — no fever, no weight loss, no fluid accumulation, and no changes in behaviour — your cat is considered in sustained remission.

Bloodwork at the end of treatment and again at the end of the observation period will confirm remission. Do not stop treatment early based on clinical appearance alone — many cats look healthy before the virus is fully suppressed. Stopping short increases the risk of relapse.

The total cost of treatment depends on your cat's weight, the FIP type, and whether you use injectables or oral capsules. For a standard 84-day course, most owners should budget for 3 monthly packs of capsules or the equivalent in injectable vials, adjusted for their cat's weight bracket.

We recommend ordering all 3 packs at the start of treatment to avoid any supply interruption mid-course. If cost is a concern, contact our treatment team — we can discuss the most efficient treatment configuration for your cat's weight and condition. We also encourage owners with unused medication after a completed treatment to donate it to families who cannot afford a full course.

The earliest signs of FIP are often non-specific and easy to overlook. Persistent fever that does not respond to antibiotics is typically the first indicator. This is usually accompanied by loss of appetite, unexplained weight loss, lethargy, and a dull or unkempt coat. Some cats also develop mild digestive upset in the early stages.

As the disease progresses, more specific signs emerge depending on the form. In wet FIP, a visibly swollen or distended abdomen develops as fluid accumulates. In dry FIP, signs vary more widely and may include neurological changes such as loss of coordination, tremors, or seizures, as well as eye abnormalities like cloudiness or uneven pupil size. If your cat is showing any combination of these early signs — especially persistent fever alongside weight loss — contact your veterinarian immediately. Early diagnosis and prompt treatment significantly improve outcomes.

Yes — with treatment. FIP was once considered almost universally fatal, and without antiviral intervention it still carries an extremely poor prognosis. The median survival time without treatment is approximately 9 days from the point of diagnosis.

With GS-441524 antiviral treatment, the outcome has changed fundamentally. Across multiple independent clinical studies covering over 650 cats, the combined treatment success rate is approximately 92%. The majority of cats that complete the full 84-day protocol reach sustained remission and go on to live normal, healthy lives. The key factors that determine survival are starting treatment as early as possible, dosing correctly by body weight throughout the protocol, and completing the full 84 days without interruption. If your cat has been diagnosed with FIP, contact our treatment team immediately — time is the most critical variable.

WHAT YOU SHOULD KNOW ABOUT FIP TREATMENTS

The standard treatment course is 84 days (12 weeks). Most cats complete the full protocol and achieve remission within this period.

In practice, treatment duration can vary. Cats that begin treatment in the early stages of FIP typically respond faster. Those with advanced disease, neurological involvement, or ocular complications may require an extended course beyond 84 days. Your cat's bloodwork and clinical response at regular checkpoints will guide any adjustments.

GS-441524 is an antiviral and is generally compatible with other medications used to support your cat's overall health during treatment.

One exception: lysine is not recommended alongside GS-441524. Research has shown that lysine supplementation does not benefit cats with viral infections and may interfere with treatment. If your cat is currently taking lysine, discontinue it before starting the FIP treatment protocol.

If you are unsure whether a specific medication or supplement is compatible with GS-441524, contact our treatment team before combining.

Nutrition plays an important supporting role during treatment. High-quality protein helps maintain body weight and supports immune function — cooked fresh fish, chicken, or other natural whole foods are good options and are generally well tolerated.

Appetite loss is common in FIP cats, particularly in the early weeks of treatment. If your cat is reluctant to eat, warming the food slightly or offering smaller, more frequent meals can help stimulate interest.

If your cat develops diarrhea during treatment, temporarily switching to a dry food diet for a few days can help firm the stool. If diarrhea persists beyond 48 hours or is accompanied by lethargy or vomiting, contact our treatment team — it may indicate a dosing or absorption issue that needs attention.

Avoid raw fish during treatment. Raw fish contains thiaminase, an enzyme that breaks down thiamine (Vitamin B1), which can cause neurological complications in cats already under systemic stress.

As treatment takes effect, you will typically see your cat's appetite return and body weight increase — both are positive signs of recovery. Weigh your cat once a week throughout the treatment course and adjust the dosage accordingly, as GS-441524 and E

INJECTION TREATMENT

GS-441524 and EIDD-1931 are dosed by body weight and severity of FIP symptoms. As a cat's weight increases, the total dose in milligrams increases — and so does the volume of liquid required per injection.

Higher concentrations allow us to deliver the correct dose in a smaller, more comfortable injection volume. A 20 mg/mL solution is well suited for small to medium size cats, while 30 mg/mL and 40 mg/mL formulations are designed for larger cats or severe cases where keeping injection volume low is a clinical priority.

Selecting the right concentration is part of how we ensure each cat receives precise, comfortable treatment — not a one-size-fits-all approach.

The standard treatment protocol for most FIP cases is one injection or capsule per day, dosed by body weight, for 84 consecutive days.

If your cat is presenting with life-threatening symptoms, twice-daily dosing may be appropriate — two injections administered 12 hours apart, each at 50% of the total daily dose. If you are unsure whether your cat's condition warrants this protocol, contact our treatment team before adjusting.

To determine the correct dose for your cat, use our [Dosage Calculator].

We strongly advise against reducing the dosage at any point during treatment. Underdosing does not slow FIP — it gives the virus the opportunity to adapt, potentially making it resistant to GS-441524 and harder to treat. Completing the full dose for the full duration is the single most important thing you can do to protect your cat's chance of recovery.

Yes, most cat owners administer treatment at home without difficulty. Subcutaneous injections are straightforward once you know the technique, and doing them yourself removes the cost and stress of daily veterinary visits for your cat.

Injection supplies (needles, syringes) are available at most local pharmacies.

We recommend two ways to get comfortable with the technique before starting:

Watch our step-by-step instructional video, which walks you through the full process of administering a subcutaneous injection at home. Alternatively, ask your veterinarian to demonstrate the technique in person during your next visit — most are happy to show you.

ORAL TREATMENT

For best results, oral capsules are recommended once your cat's condition has stabilised — typically after an initial 30-day injection phase, or when your cat is consistently showing the following signs of recovery:

Eating well with a healthy appetite
Normal bowel movements
No neurological symptoms

Transitioning to capsules before the cat has stabilised may reduce treatment effectiveness, as absorption of the oral formulation depends on adequate digestive function. If you are unsure whether your cat is ready to transition, share your cat's latest bloodwork with our treatment team and we will advise.

Oral capsules depend entirely on your cat's digestive system to absorb the medication. When that system is compromised — for any reason — capsules cannot deliver a reliable dose, and injectable treatment must be used instead.

Avoid oral capsules in the following situations:

Ocular or neurological symptoms are present.
These forms of FIP require consistent, precisely controlled drug levels in the bloodstream. Injections bypass the digestive system entirely and deliver the medication directly — making them the only reliable option until these symptoms resolve.

Your cat has diarrhea or is vomiting intermittently.
An irritated or inflamed gut cannot absorb medication effectively. Switching to capsules during this period risks underdosing, which can slow recovery and increase the risk of viral resistance.

Your cat is not eating voluntarily and requires force-feeding or subcutaneous fluid support.
A cat in this condition has compromised gut motility and hydration — both of which are essential for oral drug absorption. Capsules administered in this state may pass through the system without being properly absorbed.

If any of these conditions apply to your cat, continue with injections until your cat has fully stabilised. If you are unsure whether your cat is ready to transition to oral treatment, share your latest bloodwork with our treatment team and we will advise.

Dosage: one capsule daily, administered at the same time each day.

Consistency is critical. GS-441524 works by maintaining a sustained antiviral presence in your cat's system — missed doses create gaps that allow the virus to recover and replicate. Do not skip days, even if your cat appears to be improving.

Continue treatment for the full 84 days. If all clinical symptoms resolve before day 84, do not stop early. Full remission is only confirmed through bloodwork, not clinical appearance alone — many cats look healthy weeks before the virus is fully suppressed. Stopping early is one of the leading causes of relapse.

If you miss a dose, administer it as soon as you remember. If it is close to the time of the next scheduled dose, skip the missed dose and continue normally. Do not double dose.

As your cat gains weight during treatment — which is a positive sign of recovery — the daily dose must increase proportionally to remain effective.

If your cat has crossed into a higher weight bracket, switch to the corresponding capsule strength immediately. For example, a cat that has grown from 2.4 kg to 2.8 kg should transition from the pink capsules to the green capsules.

Continuing on a lower-strength capsule as your cat gains weight means the active ingredient is no longer being delivered at the therapeutic dose required to suppress the virus. This is one of the most common and easily preventable reasons treatment loses effectiveness mid-course.

Weigh your cat every two weeks throughout the 84-day protocol and cross-reference against our dosage chart to confirm you are on the correct capsule strength.

Each pack contains 30 capsules — a 30-day supply at the standard protocol of one capsule per day.

A complete 84-day treatment course requires 3 packs. We recommend ordering all 3 packs at the start of treatment to avoid any interruption in dosing. Running out of medication mid-course and waiting for a new shipment creates gaps that can compromise treatment effectiveness and increase the risk of relapse.

Give the capsules at least 5 days before assessing response. Clinical improvement is rarely visible in the first few days — blood markers and subtle behavioural changes are more reliable early indicators than visible symptoms alone.

If there is no meaningful improvement after 5 days, there are two likely causes: the current dose is insufficient for your cat's weight or FIP severity, or the digestive system is not absorbing the capsules reliably enough to maintain therapeutic drug levels.

Your options, in order of preference:

Switch to injections. This is the most effective course of action. Injections bypass the digestive system entirely, delivering the active ingredient directly into the bloodstream at a consistent, predictable concentration. If your cat is not responding to capsules, injections remove absorption as a variable and give you the clearest picture of whether the dosage itself needs adjustment.

Increase to 2 capsules per day. If switching to injections is not immediately possible, doubling the oral dose can compensate for partial absorption. This is a temporary measure, not a long-term protocol adjustment.

Switch to a higher concentration capsule. If your cat's weight has increased since starting treatment, confirm you are on the correct capsule strength using our dosage chart.

If your cat's condition is actively worsening rather than simply not improving, do not wait — contact our treatment team immediately. Worsening symptoms require prompt protocol reassessment, not a wait-and-see approach.

Every cat absorbs medication differently. Genetics, gut health, bodyweight, and the stage of FIP infection all influence how much of the active ingredient reaches the bloodstream after an oral dose. This is why two cats of identical weight on identical protocols can show different rates of improvement.

The precise absorption rate for an individual cat can be measured through a diagnostic procedure called High-Performance Liquid Chromatography (HPLC) — a laboratory method that analyses drug concentrations in the blood. While HPLC provides the most accurate picture of how much active ingredient a cat is actually receiving, it is a specialised and costly test that is not routinely available in most veterinary settings.

In practice, clinical response and regular bloodwork remain the most accessible and reliable tools for monitoring treatment effectiveness and adjusting the protocol when needed.

Both are effective treatments for FIP. The right choice depends on your cat's current condition, not personal preference.

Injections
Injections deliver GS-441524 directly into the bloodstream, bypassing the digestive system entirely. This means the active ingredient reaches therapeutic levels quickly, with a predictable and consistent dose every time. For this reason, we recommend starting all FIP treatment with injections — particularly in the early stages when the disease is most active and precise drug delivery is critical.

Oral Capsules
Capsules are easier to administer, painless, and practical for long-term home treatment. However, the active ingredient must pass through the digestive system before reaching the bloodstream, which introduces two variables: delayed onset and uncertain absorption. It is impossible to know exactly how much GS-441524 has been absorbed from any given capsule.

Why this matters clinically
FIP frequently damages the organs of the digestive tract — including the stomach, intestines, liver, and kidneys — before spreading systemically. When these organs are inflamed or compromised, absorption of oral medication is significantly reduced. Introducing capsules too early, before the digestive system has had a chance to recover, risks underdosing — which prolongs treatment and increases the likelihood of relapse.

Our recommendation
Start with injections. Transition to capsules only once your cat's condition has stabilised — good appetite, normal bowel function, and no neurological or ocular symptoms. Use our [transition checklist] or contact our treatment team if you are unsure when to make the switch.

Yes, you can switch from oral capsules to injectable treatment at any point during the protocol.

When making this transition, the starting injection dose is 10 mg/kg, regardless of the capsule strength your cat was previously on. This is because our capsules are formulated at a higher concentration than the injectable solution — the two delivery formats are not directly interchangeable on a mg-for-mg basis, and using the standard FIP injection dose without adjustment risks delivering more than intended.

Do not attempt to calculate the equivalent injection dose yourself based on your capsule dosage. The relationship between oral and injectable concentrations involves absorption variables that make direct conversion unreliable.

Contact our treatment team before making the switch. We will confirm the correct injection dose based on your cat's current weight, FIP type, and clinical status — and advise on whether a transition is appropriate at this stage of treatment.

We do not recommend oral capsules for relapse treatment. When FIP relapses, the virus has regained an active presence in the body — often more aggressively than the initial presentation. This is not the moment to introduce absorption uncertainty into the protocol.

Injections are the required treatment for relapse.

Relapse dosing is higher than the standard starting dose — typically 12–15 mg/kg per day — to rapidly suppress viral activity and regain control of the infection. Injections ensure this elevated dose reaches the bloodstream fully and consistently from day one.

Attempting to manage a relapse with oral capsules risks underdosing at the most critical point in your cat's treatment journey. The consequences — a second relapse, accelerating organ damage, or viral resistance — are significantly harder to reverse.

Contact our treatment team immediately if your cat has relapsed. Do not attempt to restart treatment independently. Relapse cases require individual assessment — the correct dose, duration, and monitoring protocol will depend on how long after completing treatment the relapse occurred, which symptoms have returned, and your cat's current bloodwork.

The sooner treatment is restarted with the correct protocol, the better the outcome.

You may use a higher-strength capsule than the one recommended for your cat's weight — but never a lower one.

A higher-strength capsule delivers more active ingredient per dose, which provides a safety margin without clinical risk. A lower-strength capsule will underdose your cat relative to their body weight, reducing treatment effectiveness and increasing the risk of viral resistance and relapse.

However, routinely using a higher strength than necessary is not recommended without clinical justification. If your cat's weight falls clearly within the range for a specific capsule class and treatment is progressing well, there is no clinical benefit to upgrading — it adds cost without improving outcomes.

The exception is if your cat is at the upper boundary of a weight bracket and gaining weight during treatment. In that case, moving up to the next capsule class proactively makes sense to avoid falling behind the therapeutic dose as weight increases.

When in doubt, use our [Dosage Calculator] or contact our treatment team to confirm the correct capsule class for your cat's current weight before making any changes.

Most cats show visible signs of improvement within 10 to 15 days of starting treatment. Some respond faster — noticeable changes within 5 days are not uncommon, particularly in cats that begin treatment in the earlier stages of FIP.

Early signs of response typically include increased energy and activity, improved appetite, reduced fluid accumulation in effusive cases, and a general return of normal behaviour.

Blood markers — including white cell count, albumin, globulin levels, and the A/G ratio — often begin shifting toward normal range within the first two to four weeks, sometimes before visible clinical improvement is apparent. This is why regular bloodwork during treatment is valuable even when your cat appears to be doing well.

If there is no visible improvement and no positive movement in bloodwork after 10 to 14 days, contact our treatment team. It may indicate an absorption issue, an insufficient dose, or a need to switch from capsules to injections.

GS-441524 oral capsules are generally well tolerated by most cats. Serious adverse effects are uncommon, and the majority of cats complete the full 84-day course without significant issues.

Some cats may experience mild side effects during treatment, including reduced appetite in the early weeks, minor digestive sensitivity, or broken whiskers — a cosmetic effect that resolves after treatment ends. Routine bloodwork during treatment will monitor for any changes in liver enzymes or white blood cell count, both of which are manageable if detected early.

GS-441524 is compatible with most medications and supplements. If your veterinarian has recommended additional treatments or supplements alongside FIP therapy, these can generally be continued. The one notable exception is lysine supplementation, which is not recommended during GS-441524 treatment.

If you notice any unusual symptoms or changes in your cat's condition during treatment, contact our treatment team rather than adjusting the protocol independently.

Consistency is ideal, but a degree of flexibility is acceptable. If you cannot administer the capsule at the exact same time each day, aim to stay within a 3-hour window of the previous day's dose — no more than 1.5 hours earlier or 1.5 hours later.

Beyond this window, the active drug level in your cat's bloodstream may drop below the concentration needed to effectively suppress the virus, reducing treatment efficacy for that day.

A practical approach is to tie the daily dose to a fixed routine — your cat's morning meal, for example — rather than a specific clock time. This makes it easier to stay consistent across days when your schedule changes.

If you occasionally fall outside the 3-hour window, do not double dose the following day to compensate. Simply resume the normal schedule and ensure the remaining doses are as consistent as possible. If missed or late doses are becoming a pattern, contact our treatment team — there may be a more practical protocol adjustment we can recommend.

Opened or partially used packages cannot be accepted for return. Once the seal is broken, we are unable to verify the integrity or storage conditions of the product, and accepting returns of opened pharmaceutical products would compromise the safety standards we hold ourselves to.

If you have unused capsules or vials from a completed or discontinued treatment course, we encourage you to donate them rather than discard them. FIP treatment is a significant financial burden for many cat owners — your unused medication could make the difference for a family that cannot afford a full course.

Consider reaching out through FIP support communities and forums, or ask your veterinarian if they are aware of patients currently in need. Every capsule counts.

STORAGE INSTRUCTIONS

For short-term storage of 30 days or less, keep at room temperature below 40°C, away from direct sunlight and heat sources.

For long-term storage beyond 30 days, keep the injectable solution between 10°C and 30°C. Do not refrigerate or freeze. Low temperature storage may cause GS-441524 to precipitate out of solution, render the injectable solutions less effective.

Store at room temperature below 30°C, away from direct sunlight. Capsules remain stable for up to 2 years under these conditions. Refrigeration can prolong shelf-life of oral capsules.

SHIPPING AND CUSTOMS CLEARANCE

We ship globally. Estimated delivery times from dispatch are as follows:

Asia & GCC: 1–3 business days
Europe (including UK): 1–3 business days
USA, Canada & Australia (major cities): 1–3 business days
Mexico & Colombia: 1–3 business days
All other countries: 3–7 business days

All orders are processed and dispatched within 24 hours of payment confirmation. You will receive a tracking number by email once your order has shipped.

Time-sensitive cases: If your cat's condition is critical and you need medication urgently, contact our team via live chat before placing your order. We will do everything possible to prioritise dispatch and advise on the fastest available shipping option to your location.

We ship to the vast majority of countries worldwide. In some cases, logistical limitations or local customs regulations prevent us from delivering to specific destinations.

If your country is not available at checkout, please contact our team directly via live chat before giving up on your order. In many cases we can identify an alternative shipping route or advise on the fastest available option to reach you.

We understand that for a cat with FIP, access to treatment is urgent — we will always try to find a solution.

95% of orders are dispatched within 24 hours of payment confirmation.

The remaining 5% are dispatched within 3 business days. Delays may be caused by uncontrollable events across the regions we operate in — including national, religious, and cultural observances, natural disasters, worker protests, even geopolitical instability. We operate across multiple time zones and jurisdictions, and our local logistic partners observes a broad range of public holidays as a result.

If your cat's condition is critical and you need same-day dispatch, contact us via live chat immediately after placing your order and we will do our best to prioritise it.

Once your order has been paid, it will be scheduled for pickup with 24 hours. Once your package as been picked up, you will receive an email containing your tracking number. We ship via FedEx or DHL Express depending on your location.

You can track your shipment in real time at:

If you have not received a tracking email within 24 hours of your order confirmation, check your spam or junk folder first. If it is not there, contact our team via live chat and we will locate your shipment immediately.

If you live in North America, Oceania or Europe, GCC or Asia, your order will be fulfilled by local warehouse. As a result there is not custom clearance needed. For orders outside of these regions, about 10% of packages are randomly picked by custom for examination and clearance.

We manage our side of the process fully. Every shipment is dispatched with complete import declaration documentation, which we provide directly to the carrier — FedEx or DHL — to initiate customs clearance (when needed) on your behalf.

In most cases, your order will clear customs without any action required from you.

In some instances, your local customs authority may contact you directly to request additional documentation. If this happens, do not be alarmed — it is a routine part of international small package shipments in certain jurisdictions. Contact us immediately at info@curefip.com and we will provide everything you need to complete the clearance process promptly.

One practical note: customs processing times vary by country and are outside our control once the shipment has left our facility. If your order is time-sensitive, factor in the possibility of a short customs hold when planning your treatment start date. If you are unsure about customs requirements in your country, contact us before placing your order and we will advise.

PAYMENT OPTIONS

We accept:
Visa, MasterCard, PayPal (Worldwide)
Wechat Pay and Alipay (China and SE Asia)

If none of our standard payment options are available to you, the simplest solution is to ask a trusted family member or friend to complete the payment on your behalf using their account — you can then reimburse them directly.

Alternatively, contact our team via live chat before giving up on your order. We serve customers across a wide range of markets and occasionally have additional payment arrangements available depending on your location that are not listed at checkout.

We understand that for a cat with FIP, access to treatment cannot wait — we will always try to find a workable solution.

TAXES

We do not charge taxes on product orders.

Some ancillary services — such as local delivery in certain countries — may be subject to local taxes including VAT or GST, depending on the regulations in your jurisdiction. Where applicable, any such charges will be clearly displayed at checkout before you confirm your order. You will never encounter an unexpected tax charge after payment.

If you have questions about whether taxes apply to your specific location before placing an order, contact our team via live chat and we will clarify what to expect at checkout.

For most of our customers, the answer is nothing.

We operate local warehouses across our major markets, which means orders are fulfilled domestically without crossing an international border. If you are located in any of the following regions, no import tax applies to your order:

North America
Europe
Oceania (Australia & New Zealand)
Japan & Korea
Southeast Asia

For customers in Latin America and the GCC (Gulf Cooperation Council):
Your order will be shipped internationally. Import duties are not applied automatically — they are only assessed if your package is selected for inspection by your local customs authority, which occurs on a random basis. In our experience, the majority of shipments pass through without incident. In cases where duties are assessed, the amount is typically small.

If you are unsure which category applies to your location, or want to understand what to expect before placing your order, contact our team via live chat. We ship to customers across all of these regions daily and can give you a clear picture of what others in your country have experienced.