Needle gauge

Last updated August 2026

The thickness of a needle; a higher gauge is thinner. Insulin syringes for subcutaneous peptide injections are typically fine (high-gauge, e.g. 29–31G) for comfort.

Gauge numbering runs counterintuitively: a larger number means a thinner needle, so the 29-31G needles typical of insulin syringes are quite fine. Gauge affects comfort and how quickly solution can be drawn or injected, not the dose itself, so it plays no part in the reconstitution math; the units and concentration are identical whichever fine needle is used.

Educational reference only — not medical advice. Always follow the guidance of a qualified healthcare professional.