For delts a 1" is sufficient, if it is tough going in...like leather, then yes most likely scar tissue and rotating your sites is highly recommended bro...if you haven't hit your glutes and quads yet...start. Lay off the delts for a bit, your scar tissue will only get worse. Follow what Steve said about immediately putting your alcohol swab, tissue, or gauze on injection site and hold...massage it a bit and let the muscle absorb the gear...and I wouldn't inject anymore that 1 ml in your delts at a time...but that is just me.
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