Sorry I mixed you up with someone else. Top of normal is listed around 250 at age 40 and 200 at age 70 so you are still in the high-normal ballpark for IGF-1.
My IGF-1 fell from 140 to 100 in roughly a month after losing weight and sleeping poorly so other factors can play a role. If nothing else changed I would be disappointed. Have you looked at straight HGH instead.