How long does it take for 7.5mg of mirtazepine to help anxiety and tremors?

2-3 weeks to start: All antidepressants generally take 2-3 weeks before they start having an effect, and 4-6 weeks for a full effect. However, given the small dose of mirtazapine, you may not experience any positive effect until you are on 15mg or 30mg a day. Also, generally there are fewer side effects and greater efficacy to increase the dose of 1 antidepressant rather than small doses of 2 or more ads.

About a week: Mirtazepine (remeron) usually takes a week or two to have an effect. 7.5 mg is a starting dose and can be increased if the desired effect is not seen after two weeks.