Well a low dose of Ozempic will have less chance of being disagreeable, and if it is disagreeable it'll likely be low enough to not have a big dehydration problem.. though it might also be low enough to not have any discernible effect. Generally takes a few months to get up to a dosage that it has the desired effect of making digestion slower thus reducing hunger and calorie intake causing a calorie deficit and weight loss.
But that's in general not sure what it is like for people that are already almost all the way to a beach bod
maybe it'll be more effective at a lower dose (seems plausible). I'm sure the medical ppl will have dosages appropriate for you and any negative reaction likely won't involve hospitals and many litres of saline IVs.