I didn’t notice any difference in appetite, but I already eat like a horse. The water retention seems to affect maybe half of people from what I see. A lot of people find it’s not noticeable or goes away after a few days or weeks of use. You’ll just have to test it out and see. You can always just use it before bed and sort of “sleep off” the side effects. That should help maximize potential sleep improvements too.
It’s possible water retention could be linked to reduced carb tolerance. I’ve seen it suggested that MK can decrease insulin sensitivity. If you have issues with blood sugar, keep an eye on that, and maybe have a GDA type supplement on hand. Straight berberine would probably be the most cost effective thing for that.
But yeah, pretty much start low, watch for side effects, don’t be afraid to stop or just change dosing to see what works best.