Injection site reactions Redness, itching, or swelling at the injection site is possible and usually resolves quickly
The simplest way to picture it: GLP-1 tells your gut to slow down, while amylin tells your brain you are full - through a different channel

Semaglutide versus dulaglutide once weekly in patients with type 2 diabetes (SUSTAIN 7): a randomised, open-label, phase 3b trial - The Lancet, Diabetes & Endocrinology Gastrointestinal tolerability of once-weekly semaglutide 2.4 mg in adults with overweight or obesity, and the relationship between gastrointestinal adverse events and weight loss - Diabetes, Obesity & Metabolism Once-Weekly Semaglutide in Adults with Overweight or Obesity - The New England Journal of Medicine Semaglutide delays 4-hour gastric emptying in women with polycystic ovary syndrome and obesity - Diabetes, Obesity & Metabolism Clinical Recommendations to Manage Gastrointestinal Adverse Events in Patients Treated with Glp-1 Receptor Agonists: A Multidisciplinary Expert Consensus - Journal of Clinical Medicine Risk of Gastrointestinal Adverse Events Associated With Glucagon-Like Peptide-1 Receptor Agonists for Weight Loss - JAMA

A doctor may suggest considering additional or alternative birth control, such as condoms or non-oral contraceptives, if people do not want to get pregnant while taking semaglutide
The side effect is non-arteritic anterior ischemic optic neuropathy (NAION)