Luke, all the research I’ve read (and there is a lot of it) is that higher Growth Hormone/IGF-1 levels translate into shorter lives. In fact a lot of effort and money (tens of millions of $ just into Loyal), is going into new drugs to lower IGF-1/GH as longevity drugs. Here are some threads and links on this: IGF-1 inhibitors and lifespan extension?
and Here: Another (likely) Longevity Drug - Somavert / Pegvisomant
GH supplementation was big in the world of “anti-aging medicine” and the A4M about 15 to 20 years ago… when people are much older and in worse shape than you (say in their 60s and 70s) it is reputed that GH can make people feel better, stronger, etc.
But as more and more research came out around IGF-1 over the decades, it fell out of favor and became known as clearly pro-aging in the long term.
But there are likely short term benefits - especially after injury, etc.
Unless you’ve seen some research I’ve missed, I suspect the ideal dosing is going to be something that is pulsatile… periodically done when you need some benefits from the increase.
More info on Loyal for Dogs and their first drug which is an IGF-1 Inhibitor:
In large- and giant-breed dogs, breeding for size caused these dogs to have highly elevated levels of IGF-1, a hormone that drives cell growth. High IGF-1 effectively drives these dogs to grow large when they’re young, but high IGF-1 levels in adult dogs are believed to accelerate their aging and reduce their healthy lifespan.
LOY-001 extends lifespan in part by reducing IGF-1 to levels seen in smaller-breed dogs. The IGF-1 axis is one of the most well-studied longevity pathways. In model organisms from C. elegans to mice, reducing IGF-1 extends healthy lifespan, and increasing IGF-1 shortens healthy lifespan. In humans, certain centenarians have been shown to have genetically lower levels of IGF-1.
The breakthrough moment for Loyal was connecting the biological mechanism of big dogs’ size to their short lifespan, and recognizing the big-dog-short-lifespan phenotype may not be inherent, but instead a type of “accelerated aging disorder”.
We designed LOY–001 as a long-acting injectable administered by your veterinarian every three to six months. In parallel, through our recently-announced partnership with Crinetics, we’re also developing LOY-003, a daily pill to address this same IGF-1 over-expression.
Here: The Search for a Pill That Can Help Dogs—and Humans—Live Longer (Wired Magazine)
Here: One Step Closer To Helping Your Dogs Live Longer (Forbes)
Here: Video Interview: Celine Halioua, Founder of Loyal, a biotech startup developing drugs to extend dog lifespan