# Pen Help: Setup, Filling & Needle Sizes | RefillPen

URL: https://www.refillpen.com/help

Last updated: 2026-10-19T19:31:59.274Z

> How to set up and load your reusable peptide pen, prime and swap cartridges, dial your units, choose a needle tip, and tell the V1, V2, V2.5, and V3 apart.