What needle size should I use for peptide injections?

For subcutaneous peptide injections, needle gauges between 29G and 31G are most commonly recommended, as higher gauge numbers indicate thinner needles that minimize discomfort. Needle length depends on body composition: 4-6mm for leaner individuals, 8mm for average body fat, and 12.7mm (half inch) for higher body fat to ensure proper subcutaneous delivery. Insulin syringes with 0.5mL or 1mL capacity are ideal for precise peptide dosing, and needles should never be reused as this dulls the tip and increases tissue trauma.