I changed my 3-year-old dd's Novolog injection site from back of arms to thighs 3 weeks ago and have noticed a huge difference in her blood sugars--they're much more stable and easier to control. She has had horrible variation in her blood sugars for much of the time since diagnosis a year ago (like 300s to 60s daily and 400s to 40s more than once weekly!), though I've been able to keep her A1cs in the 6.8-7.1 range. Now I'm able to keep her bg measurements from upper 200s to 70s daily, with variation from 300s+ to 50s a few times weekly. So much better! I always have injected Lantus in her thighs. She has big problems with bottom injections, stemming, I think, from our unsuccessful trial with the pump. Her injection sites continually got inflamed, which hurt her and lead to very inconsistent insulin absorption, so I stopped pumping after 3 mo. I read about the difference in insulin metabolism when it's injected into muscle as opposed to subcutaneous fat, and it's metabolized more quickly in muscle, leading to lows post-injection followed by highs. My source said to watch for frequent bruising as a sign of intramuscular injection. And I know that my daughter is fairly thin, so the back of her arms doesn't have much fat. Anyway, it worked for me!