"i have been on phentermine for 66 days, take 37.5 mg/day, and lost 10 lbs. however as of tomorrow i will stop taking it. it has caused a very negative change in my thoughts &amp; personality &amp; causes huge mood swings. after being on it for 2 weeks i started noticing i was super sensitive, however blamed it on pms at the time. it hasn&#039;t gotten better though. i have been irritable, angry, restless, &amp; just general feelings of sadness. the past couple days i also have been noticing &quot;flashes&quot; of something dark on the floor out of the corner of my eye but when i look in that direction nothing is there. when i read these are rare side effects i decided i need to stop taking it."