Can taking Phentermine cause a brownish discharge? I ve been taking this for 2 months now and haven t once had my period and have recently developed a bit of brownish discharge. There is no chance of pregnancy and to be sure, we took 2 tests at home and also had a blood test from my doctor (all being negative). I ve read that this medicine can really mess with a woman s monthly cycle, but I m not sure what to think about all of this. My doctor said that if I m fine with not having a cycle, I can stay on the medicine... but I just don t know if this is healthy or even safe for my body, for that matter. I m getting really nervous and would love some answers. Is this a normal side effect? I have no other symptoms of any sort. I have lost 18 lbs. on this medicine in 2 months and have changed my eating habits quite a bit. Could these be effects of this? Please, someone answer me. I m so stressed about this! Thank you!