Semaglutide was FDA approved for diabetes in 2018 (3 years ago) and in June this year for weight management. It's part of a class of medication called GLP-1 RAs which operate in a similar way (they all stimulate the same GLP-1 receptor). Liraglutide is another common one that was approved by the FDA in 2010 (11 years ago) for diabetes (by the EU in 2009) and for weight management in 2014. So there is a 3 year of history with this particular medication and an 11 year history for this class of medication.
Here's more about the history of GLP-1s and other weight loss if you'd like: https://blogs.sciencemag.org/pipeline/archives/2021/02/15/gl...
The main side effects that people seem to get are nausea and vomiting when adjusting to the dose, this is likely due to the slowing down of food leaving your stomach. This is documented in the study of nearly two thousand people which lasted for 68 weeks here [1] (where you can also see the other side effects).
It's worth noting that, as with any medication, there is a cost-benefit trade-off. In this case it will depend on someone's current weight, what they've tried in the past, and the risks of other conditions e.g. heart disease, diabetes, and their past medical history. Each person that joins Fella has an in-depth discussion about this with an independent obesity physician and is welcome to speak it through with their own PCP too.