For instance, smoking also constricts your blood vessels so if you combine it with phentermine which can do the same, and it becomes crystal clear why smokers deal with a headache when taking the drug. How to get rid of headache while on phentermine We have seen some of the possible causes of headaches while on phentermine. However, it is important we mention some ways you can get rid of headaches irrespective of the cause. Headaches remain one of the most common side effects of Phentermine 37.5mg. If you find yourself dealing with head pain over and over again on your weight loss journey, take a moment to learn the possible causes…and what you can do about it: So, if your head is constantly throbbing, consider these simple changes to get rid of a mild phentermine headache: 1. Stay Hydrated. Aim for at least two liters of water or other caffeine-free, calorie-free beverages per day, and more if your pee is not light yellow [9,10]. When you feel a phentermine headache coming on, drink 2-3 glasses of water right away. If the headache is caused (or. I do get really bad headaches/migraines even if I do eat and rarely constipation. So far I have shed 12 lbs and that is not counting this week (week 3) and last weight check-in of 196.3. If anyone. i have been on phentermine a month now and the only time i really get headaches is if i go a long time not eating. I do not know exactly how it is working for you but sometimes if I am not hungry and no I need to eat something I will have a banana or a south beach diet meal mar with has lots of protein and nutrients and I am getting what i need. Summary. Headache is found among people who take Phentermine, especially for people who are female, 40-49 old , have been taking the drug for 1 - 6 months, also take medication Xanax, and have Weight decreased. I was wondering if [phentermine caused an increased production of stomach acid because I also have IBS and when I do not take magnesium, probiotics and heartburn medicine I get this same type of pain. feels like someone is putting a knife through my stomach into my back. right straight through is the pain. I have only taken the meds for a little over a week. I don't think I can tolerate them. I do get more nauseous when standing and even more nauseous the longer I stand in one place, which also makes me light headed & increases my headache pain. I went to my doctor Friday. I went to my doctor Friday. I do not get any headaches from taking the Phentermine. However, I find that I am not getting the sleep I need. I also, still have late night cravings while I sit wired. I would think the doctor that has put you on these products can adjust your program.