Jan,
I am actually losing weight since going on Lithium, and haven't noticed any skin problems. Some of the downsides are: reduce/eliminate caffeine intake and in the first month or so an almost unquenchable thirst or dry mouth.
Since going on Lithium, I've cut all soda/pop out of my diet and really cut back on the coffee, but I haven't been able to totally give it up nor do I think I ever will LOL. But, I have drastically increased the amount of water I drink (about 80 oz. a day) which I think is also helping with the weight loss (4 months, 25 lbs - and counting!!)
I get my levels checked every three months, and after my next draw, since I'm doing so well, my doc is going to every 6 months unless I run into problems. I'm still on my starting dosage of 900mg/day.
Those are the only side effects I've experienced, but as we all know, every body is different. Good luck with your pdoc. Lithium isn't as bad as I thought it would be
Huge Hugz and Much Love,
Dol