I've hit the same insulin syringe upwards of 20 times (500mcg doses of a 10mg vial of MT2) countless times over the years. Never an issue. Yea, by the end I'm essentially puncturing skin with a blunt needle, but I'm dealing with worn out leather anyway. What I don't do is reuse anything dealing with IM. Those are one-and-done. Subcutaneous, though? No problem. Never a single problem aside from compound-specific irritation like from MOTS-C. Don't even site prep with alcohol pads for subcutaneous. IM gets the full treatment, though.junkies