The heart
In cats with subclinical hypertrophic cardiomyopathy, a delayed-release rapamycin formulation was associated with slower progression of left ventricular wall thickening. It slows the disease; it does not reverse it.
Strongest evidence
Feline longevity care
You already noticed. You just didn’t have a name for it.
She doesn’t make the jump to the window ledge in one go anymore.
The 2am sprint down the hallway stopped happening months ago.
She still purrs when you come home. She just takes a little longer to get there.
None of that is “just old age”. It is biology — and for the first time, biology we can act on.
Nobody told you there was anything to do about it
For most of veterinary history there wasn’t. You brought your cat in, the bloodwork came back “normal for her age”, and you went home with nothing to do but watch.
You are the kind of owner who reads the lab values. Who notices the change in the jump before anyone else does. Who has already done the arithmetic on how many years are likely left.
That instinct was right. What has changed is that the biology of feline aging is now a target — not a metaphor.
1 in 3
cats over nine are affected by heart disease — and roughly a third of them have no murmur at all.
Hypertrophic cardiomyopathy is the most common feline heart disease. In cats with subclinical HCM, a delayed-release rapamycin formulation has been associated with slower progression of wall thickening.
The goal isn’t more years. It’s more of her.
Lifespan is a number on a chart. Healthspan is whether she still does the things that make her recognisably herself.
- Making the counter in one jump instead of two.
- Grooming properly again, so the coat stops looking neglected.
- Coming to find you rather than waiting to be found.
- Playing past the first thirty seconds.
Four things feline aging takes, and where the research is
Rapamycin acts on mTOR — the pathway that decides whether cells grow or repair themselves. Here is what that means organ by organ, with the evidence stated honestly.
The kidneys
Chronic kidney disease is the most common serious illness of older cats, driven by fibrosis. mTOR signalling participates in that fibrosis, and clinical studies in cats are underway — no protocol has yet been shown to change the course of feline CKD.
Under investigation
Cancer risk
mTOR inhibition is an established anticancer mechanism in human oncology, and preliminary signals have been reported in feline mammary and squamous cell carcinomas. Evidence in cats remains limited.
Preliminary
Whole-body aging
Partial mTOR inhibition activates autophagy — the cell’s cleanup process — which is associated with lower chronic inflammation. In laboratory species this translates into longer healthy lifespan.
Proven in lab species
One cat
Sisu was eleven when the murmur turned into a diagnosis
Her owner brought her in for a dental. The vet heard a gallop rhythm, and the echocardiogram found what the stethoscope suspected: hypertrophic cardiomyopathy, still subclinical. No signs. No symptoms. A heart wall already thicker than it should be.
The conversation that follows that diagnosis used to be short. Monitor. Recheck in six months. Hope it stays slow.
Instead her cardiologist and our veterinary team built a protocol: weight-calibrated, once-weekly, with echocardiography tracking the thing that actually matters. Eighteen months on, Sisu is thirteen, and the wall measurement has held.
One cat’s course is not a result you should expect. Individual outcomes vary, and this story is not a medical claim.
This is likely right for your cat if…
Most cats we start are healthy. The point is to act before there is a crisis to react to.
- She is seven or older — or a breed with known cardiac risk at any age.
- She is a Maine Coon, Ragdoll, British Shorthair, Sphynx or Persian.
- A murmur, gallop rhythm or raised NT-proBNP has been noted.
- Her bloodwork is “normal for her age” and you have never quite believed that phrase.
- You have watched an older cat decline before and would rather not repeat it.
- You want something evidence-led rather than another shelf of supplements.
- Your own vet is willing to co-manage — many of our members work that way.
It is not right for every cat. Diabetes or impaired glucose regulation, active infection, significant liver disease, planned surgery, or pregnancy all rule it out — which is exactly what the veterinary review checks before anything is prescribed.
This is a protocol, not a product
The molecule is the easy part. What makes it work — and what makes it safe — is everything around it.
Dose calibrated to her weight
0.4 mg, 1.2 mg or 2.4 mg, scaled to body weight. Longevity dosing is a fraction of the dose used in transplant medicine, and it is intermittent rather than daily.
Once weekly, with food
A delayed-release, acid-resistant tablet. Flavoured oral suspensions exist for cats that refuse tablets — the protocol only works if it is actually given.
Screening before the first dose
Health history, current medications and baseline bloodwork. Rapamycin is metabolised through CYP3A4, so interactions are checked rather than assumed.
Monitoring that tracks the disease
Periodic bloodwork, weight, and where HCM is involved, echocardiography — measuring the wall itself, not just how she seems.
Given properly, this is a monitored medical protocol. Given without oversight — wrong dose, no screening, no bloodwork, unchecked interactions — it is neither safe nor useful. That difference is the whole service.
Three ways to start
Rapamycin is a prescription medicine. Every route below ends with a licensed veterinarian making the call.
Work with your own vet
Already have a vet who knows your cat? Bring them the protocol. We will share dosing guidance and monitoring schedules so everyone stays aligned.
Read the science →Recommended
Therapy on membership
The veterinary review, a protocol calibrated to your cat, ongoing monitoring, and the next box shipping automatically as the current one runs out — 10% below the single-box price, with nothing to reorder. This is where most owners start.
View the cat therapy →A single course
Prefer to start with one box and decide later? The same veterinary review applies, with nothing recurring.
View the cat therapy →What is another two good years with her worth? We can’t price that. We can tell you what the programme costs, and exactly what is in it.
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Judgment, not access
Longevity medicine is not about getting hold of a molecule. It is about the right dose, the right monitoring, at the right time — and knowing when the answer is no. Every Rapavie protocol is designed and overseen by veterinarians experienced in feline longevity medicine. We are not selling pills. We are building a medical relationship that adapts as your cat ages.
Licensed veterinariansBoard-reviewed protocolsIndependent veterinary oversight
Die ehrlichen FAQ.
Does my cat need a prescription?+
Yes. Rapamycin is a prescription medicine. A licensed veterinarian reviews your cat’s history and issues the prescription where it is appropriate, and you can involve your own vet at any point in the process.
My cat isn’t sick. Why would I start now?+
Because the biology of aging starts long before the diagnosis does — and the feline HCM evidence is strongest in cats with subclinical disease, meaning disease present but no signs yet. Waiting for symptoms means waiting for the point where less can be done.
How is it given?+
One delayed-release tablet, once a week, with food. The acid-resistant coating protects the molecule through the stomach. Flavoured oral suspensions are available for cats that refuse tablets.
What about interactions with her other medications?+
Rapamycin is metabolised through the CYP3A4 enzyme system, so some antifungals, antibiotics and antiseizure drugs can raise or lower its levels. Every medication and supplement is reviewed before the first dose.
What side effects should I expect?+
At longevity doses, most cats show none. The most commonly reported effect is mild, transient stomach upset in the first weeks. Mouth ulcers and delayed wound healing are recognised effects of mTOR inhibition and are part of why periodic bloodwork is included.
Which cats should not take it?+
Cats with diabetes or impaired glucose regulation, active or recurrent infection, significant liver disease, or a planned surgery, and pregnant or nursing cats. The veterinary review screens for all of these.
How will I know whether it is working?+
For cardiac cases, echocardiography measures the wall directly — that is the objective answer. Otherwise, bloodwork and weight are tracked, and owners report on appetite, movement and engagement. Subjective impressions are noted, not treated as proof.
What does it cost?+
A single box starts at €99 — four tablets, one month — and includes the veterinary consultation, personalised dosing and delivery. On a membership the same box is 10% less and arrives automatically. Pause or cancel anytime.
Healthy years are built early. Waiting doesn’t improve the biology.
Start with the veterinary review. If your cat is not a candidate, we will tell you — that answer is part of the service too.
This page is educational and is not veterinary advice. Rapamycin is a prescription medicine; whether to use it is a decision made with a veterinarian who has examined your animal. No medicine is licensed to “extend longevity” — the statements here describe published research and ongoing studies.