IGF-1 LR3 dosage for a large / giant breed
over 77 lb (35 kg)
The short answer
For a dog weighing over 77 lb (35 kg), the dose of IGF-1 LR3 reported in the literature is 40-300 mcg per day, given once daily, over 4-6 weeks, then 4 weeks off. It is studied in this weight class primarily for sarcopenia, muscle loss in senior dogs. These figures are reported as published and are not recommendations — the dose for an individual dog must be set by a veterinarian who has examined the animal.
Worked examples at specific weights
Calculated from the reported range of 1–4 mcg per kg of body weight.
| Body weight | Calculated dose range | Frequency |
|---|---|---|
| 40 kg (88 lb) | 40–160 mcg | Once daily |
| 50 kg (110 lb) | 50–200 mcg | Once daily |
| 60 kg (132 lb) | 60–240 mcg | Once daily |
For an exact figure at your dog's weight, use the dose calculator.
Typical breeds in this weight class
German Shepherd, Labrador Retriever, Rottweiler, Great Dane, Mastiff and similarly sized dogs generally fall within over 77 lb (35 kg). Weigh your dog rather than estimating — dosing is calculated per kilogram and an estimate that is out by a few kilos changes the figure materially, particularly at the smaller end.
Before dosing at all
⚠ Contraindicated with active cancer
IGF-1 signalling directly drives cell proliferation. In a dog with an existing malignancy that is precisely the wrong signal. Screening before use is mandatory, not advisory.
⚠ Hypoglycaemia risk
IGF-1 LR3 has insulin-like activity and can lower blood glucose. Tremors, disorientation, weakness, or collapse are emergencies. Blood glucose must be monitored, and diabetic dogs require direct veterinary management.
Common questions
How much IGF-1 LR3 for a large / giant breed?+
For a dog in the over 77 lb (35 kg) range, the reported dose is 40-300 mcg per day, given once daily, typically for 4-6 weeks, then 4 weeks off. At a representative weight of 45 kg (about 99 lb), that works out to roughly 45–180 mcg per dose. These figures are reported from the source literature and are not recommendations.
How often should a large / giant breed be given IGF-1 LR3?+
Once daily is the reported frequency, over a course of 4-6 weeks, then 4 weeks off. See the cycling guide for how breaks are structured.
Is IGF-1 LR3 safe for a large / giant breed?+
IGF-1 LR3 demands more caution than anything else on this site apart from the investigational oncology compounds. Two risks are concrete rather than theoretical: it can lower blood glucose enough to cause tremors or collapse, and because IGF-1 signalling drives cell proliferation it is contraindicated in any dog with known or suspected cancer. The mandatory four-week off-cycle exists to let receptor sensitivity recover. Canine evidence is Level V — mechanistic and extrapolated, not clinical.
References
- 1.Goldspink G Mechanical signals, IGF-I gene splicing, and muscle adaptation. Physiology, 2005. PMID 16174871
Other weight classes: IGF-1 LR3 for a small / toy breed, IGF-1 LR3 for a medium breed.
Educational information — not veterinary medical advice
Everything on this page is compiled from published peer-reviewed literature for educational and research purposes. It does not establish a veterinarian-client-patient relationship (VCPR) and is not a substitute for veterinary examination and diagnosis. Most compounds described here are investigational or used off-label and are not FDA-approved for these purposes in dogs. Extralabel drug use in animals requires a valid VCPR and the direct supervision of a licensed veterinarian under AMDUCA (21 U.S.C. §360b). Dosing figures are reported as they appear in the source literature and are not recommendations.