Rapamycin for dogs: A 2026 safety & dosing guide

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As “healthspan” becomes the new priority for pet owners, Rapamycin (also known as sirolimus) has moved from experimental labs to the forefront of canine longevity. By 2026, data from major studies has provided a clearer picture of how this mTOR inhibitor can potentially slow the biological aging process in senior dogs.

Medical disclaimer: This article is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Rapamycin is currently used off-label in veterinary medicine for anti-aging. You must consult with a licensed veterinarian before starting any new medication or supplement for your dog.

What is rapamycin?

Originally discovered in soil samples from Easter Island, rapamycin is a compound that inhibits the mTOR (mechanistic Target of Rapamycin) pathway. In humans, it has long been used at high doses to prevent organ rejection. However, at the low, intermittent doses used for canine longevity, it acts as a geroprotector.

In 2026, the Dog Aging Project and its TRIAD study (Test of Rapamycin in Aging Dogs) continue to be the gold standard for research. The drug works by triggering autophagy—a cellular “cleanup” process that removes damaged proteins and organelles, effectively mimicking the life-extending benefits of caloric restriction.

Potential benefits of rapamycin for dogs

Research and real-world data from 2026 highlight several key benefits for aging dogs:

Heart health: Studies show rapamycin can improve diastolic function and reverse age-related heart thickening.
Cognitive preservation: By reducing neuroinflammation, it may delay the onset of Canine Cognitive Dysfunction (CCD).
Enhanced mobility: Owners report increased energy and a “younger” gait in dogs with age-related joint stiffness.
Cancer prevention: By regulating cell growth, it may reduce the incidence of certain age-related tumors.
Periodontal health: Recent findings suggest it may even help reduce inflammation in the gums and jawbone.

In this episode, Dr. Peter Dobias sits down with integrative veterinarian Dr. Kevin Toman to discuss the future of pet health. We move beyond traditional medicine to explore how Rapamycin (sirolimus) and other integrative therapies are helping dogs live longer, healthier lives by targeting the root causes of aging.

Is rapamycin safe for dogs?

Safety is the most critical factor for any owner. At low doses, rapamycin is generally well-tolerated, but it is not without risks. Unlike the high-dose daily regimens used in human medicine, canine anti-aging protocols use “pulsed” dosing to avoid suppressing the immune system.

Potential side effects

While rare, some dogs may experience:

Gastrointestinal issues: Temporary diarrhea or decreased appetite.
Hypertriglyceridemia: An increase in blood fats (lipids), which requires monitoring via bloodwork.
Slowed healing: It is often recommended to pause rapamycin for two weeks before and after any surgery.
Lethargy: A small percentage of dogs may seem tired shortly after their dose.

A full list of these can be found in this controlled trial used to establish the effects of short-term use.

Rapamycin dosage for dogs

Dosing in 2026 has moved toward a once-weekly or three-times-weekly “pulsed” schedule. This approach maximizes the anti-aging effect while allowing the body time to recover.

Standard dosing guidelines for anti-aging

Dog weight (lbs)	Weekly total (0.15 mg/kg)	Typical dose (mg)	Frequency
10–20 lbs	0.75 mg – 1.5 mg	1.0 mg	Once weekly
21–40 lbs	1.5 mg – 3.0 mg	2.0 mg	Once weekly
41–60 lbs	3.0 mg – 4.5 mg	4.0 mg	Once weekly
61–80 lbs	4.5 mg – 6.0 mg	5.0 mg	Once weekly
81+ lbs	6.0 mg+	6.0 mg+	Once weekly

Note: Dosage should always be calculated by a vet. Most protocols use sirolimus tablets (usually available in 0.5 mg, 1 mg, or 2 mg).

Frequently asked questions

No. While rapamycin is FDA-approved for humans, its use in dogs for anti-aging is off-label. However, veterinarians have the legal right to prescribe it if they believe it benefits the patient. In 2026, we are also seeing the emergence of LOY-002, an anti-aging drug specifically seeking FDA conditional approval for dogs. LOY-002 targets metabolic fitness specifically, while Rapamycin targets the mTOR pathway; they are the two biggest stories in 2026 veterinary medicine.

Owners typically report seeing changes in “sparkle”—increased playfulness, better sleep, and more interest in walks—within 4 to 8 weeks of starting treatment.

Generally, yes. Rapamycin is often used alongside fish oil, glucosamine, and probiotics. However, you should avoid using it with other powerful immunosuppressants unless directed by a specialist.

Most researchers suggest starting when a dog reaches “middle age” (around 7 years for most breeds, or 4–5 years for giant breeds), though it can still provide benefits to senior dogs.

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Rapamycin for dogs: A 2026 safety & dosing guide

What is rapamycin?

Potential benefits of rapamycin for dogs