If you want to go deeper on the injection process itself before reading about hardware, the complete GLP-1 injection guide is a good starting point
In 2024, a multi-society clinical practice guideline was issued jointly by the American Gastroenterological Association, the American Society for Metabolic and Bariatric Surgery, the American Society of Anesthesiologists (ASA), the International Society of Perioperative Care of Patients with Obesity, and the Society of American Gastrointestinal and Endoscopic Surgeons [112]
F., & STEP 1 Study Group (2021)
They include formulations marketed under the brand names Absorica, Amnesteem, Claravis, Sotret, and others
Compounding pharmacies must also follow rules set out by US Pharmacopeia (USP)
doi: 10.3390/nu10111772 217