"after taking doxylamine for over 8 months for severe insomnia, i have gained over 15lbs. i&#039;m only 5&#039;1&#039;&#039; &amp; 15lbs is a significant weight gain. i&#039;ve never been overweight, i&#039;ve been consuming less calories &amp; no change in weight. the doxylamine helps with my insomnia but i can not continue using it because of weight gain."