Has anyone ever lost weight while taking mirtazapine?

Hi there, I’ve been on it a week and half and am experiencing weight loss quite rapidly. I’ve got from eight stone four to seven stone twelve in that time! Very odd considering it seems to make more people gain weight.

Hi, Cookie!
It's unlikely but there have been a few reports:
"Metabolic
Very common (10% or more of users): Increased appetite (up to 17%), weight gain (up to 12%)
Uncommon (0.1% to 1% of users): Anorexia
Rare (0.01% to 0.1%of users): Weight loss"
Mirtazepine, like many other antidepressants, is more likely to cause weight gain but as you can see the majority of patients don't experience any weight change at all.