Moreover, the percentage of participants in clinical trials who stopped the treatment due to AE was 5–15% with most of the new agents, and this percentage was up to 20–30% with some of GLP-1/glucagon RA in phase 2 trials – so a considerable proportion of people may not be able to tolerate the new obesity pharmacotherapies or may be unable to titrate them to the higher and most effective doses. This evidence concerns the gene GCG and obesity due to melanocortin 4 receptor deficiency.