“IGF-1 appears constant over a 24-hour period, making it useful as a bio-marker to help assess blood levels of GH.”
And
”Fasting is not required for this test. Take all medications as prescribed.”
And from Marek it seems like it one the tests that (at least with some assays) can get wacko results if done while having somewhat recent vitamin B7 supplementation:
”Note: This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin. Cease biotin supplementation at least 72 hours prior to blood draw.”
Here are my test results. Seems that as long as I keep working on muscle and resistance training as a foundation against osteoporosis and sarcopenia and I’m not worried about those then lower might be even better?
After taking rapamycin for a couple of years, I am on a 2 month break that probably ends in March. Before I restart, I’ll report on my IGF-1 as a baseline and get it remeasured three months after that. Any problems with allowing 3 months to establish a possible change in results?
My test results, after a 2 month layoff of rapamycin, followed by 4mg rapamycin with 10oz grapefruit on a Friday, then the IGF-1 test on Monday: 74ng/mL (reference: 68-247). I’m in the 25th percentile as a 60yo male, which sounds good to me for longevity purposes. I’ll test again after a couple of months of intermittent rapamycin.
New Open Access Paper Reduced insulin/IGF-1 signalling upregulates two anti-viral immune pathways, decreases viral load and increases survival under viral infection in C. elegans by Elizabeth M. L. Duxbury & AlexeiMaklakov et al.
Yeah. It’s like free testosterone levels…. low might be best for longevity, medium might be better for (current) healthspan
… my personal goal is to maximize longevity while keeping current health status good, so rather lower than higher on IGF-1…., but seems tough to triangulate in on what exactly is optimal from the different data types that we currently have
Perhaps look into what things could be negative and make sure you don’t see any symptoms related to those.
Any idea why it might be low? I haven’t looked into it, but perhaps SGLTi nudges it down?
In adults, abnormally low levels of GH and/or IGF-1 may cause subtle, nonspecific symptoms such as:
Decreased bone density
Fatigue
Adverse lipid changes
Reduced exercise tolerance
Depression
Thinning, dry skin
They give 79–900 ng/mL as the “normal” range. They write:
Many factors can lead to having low IGF-1 levels such as: nutritional deficiencies, disorders of the pituitary gland, aging, kidney disease, liver disease, elevated estrogen.
I don’t know where I read that but doesn’t calorie restriction started in middle-aged mice not work nearly as well as it does in mice who were calorie restricted since birth?
I wouldnt be comfortable with this at all. If it were me, I would take 1-2iu of HGH per day. Every risk people bring up about a low dose of HGH has pretty much been debunked. This is not even remotely close to a bodybuilding dose. There’s no insulin sensitivity issues at this amount, especially if you’re already on an SGLT2 or Acarbose or something like that.
I really don’t think the Laron syndrome argument is the end all be all that low IGF1 is healthy. Low IGF is linked to worse cardiovascular outcomes and fixing it has shown to improve this. I doubt dwarves feel that great in their day to day lives anyway. You could probably be feeling so much better if you got that up. Optimizing hormones is criminally underrated IMO.
