Exactly, greg_boulder. And I want to add — injection site rotation matters too, but for different reasons than people think. Why rotate sites: 1. Lipodystrophy prevention — Repeated injections in the same spot can cause fat atrophy (lipoatrophy) or fat hypertrophy (lipohypertrophy). These lumps/dents alter absorption unpredictably. 2. Consistent absorption — Different body areas have different blood flow and fat thickness. If you rotate between abdomen and thigh, you may get slightly different PK profiles week to week. My recommendation: Pick ONE general area (abdomen is best for most people) and rotate WITHIN that area. Move at least 1 inch from your last injection site. Think of your abdomen as a clock — inject at 12 o'clock one week, 2 o'clock the next, etc. Stay at least 2 inches from your navel. This gives you consistent absorption while preventing tissue damage.

I'll share a tip from my endocrinologist: if you're unsure whether you're hitting SC or IM, do a simple test. After inserting the needle but before injecting, let go of the pinched skin. If the needle is in SC tissue, it'll stay put with minimal movement. If it shifts dramatically or you feel it "catch" on deeper tissue when you move, you may be in muscle. Also — if you see blood flash back into the syringe, you've hit a small vessel. Withdraw, get a new syringe/needle, and try again. This is rare with fine-gauge needles but it happens.

Super helpful thread. I'm going to: 1. Switch to 5/16" (8mm) needles for thigh injections 2. Always use the pinch technique on thigh 3. Stick to abdomen as primary site with clock rotation 4. Save the half-inch needles for abdomen only Thanks for explaining the actual pharmacokinetics behind what I was experiencing. It's not just about comfort — injection depth fundamentally changes how the drug works.