I've been using 22g 1.5 inch needles to inject into my thigh since day 1. Yesterday I got a refill which ended up being for 20g needles with 3mL syringes (for drawing up) and 23g 1.5 inch needles for injecting. The pharmacy at the clinic filled it with 23g 1 inch needles which I didn't realize until 4am when I got home. I inject into my thigh and I'm on the chubby side. I'm not sure if the 1 inch needle will be pushed into the muscle enough for my injections. Does anybody know or have experience with both 1 inch and 1.5 inch needles and would be able to help me out?

Well I'm pretty thin, but when I was inserting all of a 1" needle, I was hurting myself way more than necessary.  I'd have problems walking for 3-4 days as it was horribly sore.   I think I was going through a lot of the muscle instead of just reaching it like you need to.  I now only insert about 3/4" and I'm still getting the same rate of changes and none leaks back out.  It leaves a hard, slightly sore spot for a few days, but there's no pain when walking.    That said, even if you're bigger, 1" should be plenty to reach the muscle, but I'd call the doctor or nurse if you're uncertain, they're the professionals after all.

Ah, I'll call on Monday but won't get a call back til Thursday and won't be able to come in to pick up needles if needed for over a month.

When I used the 1.5 inch ones I'd leave maybe 1/4th of an inch out without any problems.

The first needle the nurse gave me after my prescription was a 1 inch needle, and I'm on the higher end of average weight. When we tried a larger gauge we switched to 1 and a half in needles and she taught me to leave half an inch out when injecting. Everything seems to be fine, changes are progressing, so the T's getting in.