I started taking 25mg of sertraline daily, and was wondering how likely it is that i will gain weight from it? i've also had no sex drive lately?

Only in some people: Sertraline Side Effects. Commonly reported side effects of sertraline include: drowsiness, tremor, fatigue, diarrhea, dyspepsia, nausea, insomnia, loose stools, dizziness, headache, paresthesia, delayed ejaculation, ejaculation failure, xerostomia, anorexia, diaphoresis, and decreased libido. Other side effects include: agitation, pain, vomiting, abdominal pain, anxiety, hypouricemia, and malaise. See below for a comprehensive list of adverse effects