Apart from heart problems, phentermine psychological side effects are some of the most potentially-troublesome reactions. Phentermine and depression are an especially common and worrisome duo, so it is important to monitor yourself and loved ones for signs of hopelessness or suicidal tendencies.
In fact, even though low mood is considered a rare side effect of this medication, recent data indicates that approximately 1 in 6 users have experienced phentermine depression or anxiety during their weight loss journey (
Patients taking phentermine and topiramate together (e.g. Qsymia) are at an even higher risk for suicidal thoughts or actions (
Why Does Phentermine Cause Depression?
Low mood from phentermine varies in severity: ranging from mildly bothersome sadness to severe, debilitating depression. Unfortunately, the exact cause of phentermine depression remains unknown.
However, here are three potential explanations for phentermine depression:
Research indicates that prolonged stimulant exposure can cause depression related to repeated release of critical neurotransmitters.
Phentermine affects natural levels of norepinephrine, dopamine and serotonin (the catecholamines). As a stimulant, it elevates these hormones and patients experience a boost in mood and energy – at least at first.
However, in some cases, prolonged exposure to high levels of dopamine can cause depression (
2. Amplified Emotions
Many phentermine users also report that this medication amplifies emotional reactions in all directions. As a result, people with a history of depression or other mental health problems may be more susceptible to phentermine psychological side effects (
That being said, patients with no history of mental health problems can also suffer from low mood and phentermine depression while taking this medication.
3. Hormonal Fluctuations
Depression while taking phentermine could also be related to hormonal changes associated with major weight loss.
For example, dramatic fluctuations in hormones like estrogen can precipitate periods of low mood and anxiety. If you suspect hormonal changes as a contributing factor in your phentermine depression, speak with a doctor about possible solutions.
Depression While Taking Phentermine and Topiramate
Qsymia is a popular weight loss pill that contains two active ingredients: phentermine hydrochloride and topiramate extended-release.
The chemicals work together to promote weight loss. Phentermine acts as a powerful CNS stimulant to suppress appetite and boost energy, while topiramate (an antileptic drug) helps control cravings and make food less appealing.
The second ingredient, topiramate, has been linked with increased risk of depression and suicidal ideation.
In an analysis of almost 200 clinical trials, patients taking antiepileptic drugs like topiramate were twice as likely to experience suicidal behavior or ideation, when compared to patients taking a placebo (sugar pill). This dangerous side effect begins about one week after starting topiramate or Qsymia and persists throughout the course of treatment (
How to Cope with Phentermine Depression
Depression is a documented side effect of this medication. Seek help if you are feeling unusually emotional or down.
That being said, if your low mood is a more mild, passing sadness that feels like it can be reasonably managed at home, consider these strategies to combat less severe phentermine mental side effects:
Talk About It
Vocalizing your feelings can help put things in perspective and make you feel less alone. It also proves helpful to remember that phentermine may be amplifying your emotions and making things seem more overwhelming than usual.
If you do not have anyone to confide in in-person, the Phentermine.com support group on Facebook is a great way to connect with other phentermine users, who may be facing similar challenges.
If you prefer to keep things to yourself, journaling can be a great tool too!
Make Time to Sleep
It sounds cliché, but life’s challenges often seem less overwhelming after a good night’s sleep.
Even scientific research shows that depression and insomnia are tightly linked. Higher rates of insomnia are observed among depressed patients, while patients with insomnia often report worse depressive symptoms (
Go for a Walk
Exercise is a natural mood booster.
During a good workout, the brain produces extra feel-good chemicals that improve mood and reduce stress & anxiety (
While all types of workouts help, team sports, cycling and aerobic classes or going to the gym are correlated with the greatest reduction in poor mental health days (
Many people reach for comfort foods like ice cream or fried foods when they feel low, but unhealthy emotional eating is detrimental to both your physical and your mental health.
Instead, stock-up on feel good foods like bananas, Brazil nuts, oily fish, whole grains, lentils, yogurt, eggs, dark chocolate and spinach. These items are rich in vitamins and minerals that contribute to higher serotonin production and improvement in mood.
Give yourself permission to put your own health and well-being first, especially if you’re struggling with low mood associated with phentermine and depression.
Reduce stress and anxiety by finding a relaxing hobby, listening to your favorite music, indulging in a soothing massage, or just taking a few hours of “me time” to rest and recharge each week.
Ask for Help
Whether it is phentermine side effect or a manifestation of something deeper, depression is often too big to manage alone.
He or she may try reducing your dosage or switching you to a different medication, but if the low mood remains it is prudent to seek professional mental health support. Your prescribing doctor may be able to offer advice, but you may also consider asking him or her for a referral to a psychologist.
- Members of “Losing Weight with Phentermine” Support Group on Facebook & Phentermine.com Forum. (2019, March 13). [User Report of Common Phentermine Side Effects]. Unpublished raw data.
- VIVUS, Inc. (2017). Highlights of Prescribing Information.
- Neel, A.B., Jr. (2012, February). Medications That Can Cause Depression.
- U.S. Food and Drug Administration. (2012). Adipex-P (phentermine hydrochloride) capsules label [Brochure].
- Nutt, D., Wilson, S., & Paterson, L. (2008). Sleep disorders as core symptoms of depression. Dialogues in Clinical Neuroscience, 10(3), 329-36.
- Mayo Clinic Staff. (2018, December 14). 7 great reasons why exercise matters.
- Chekroud, S. R., Gueorguieva, R., Zheutlin, A. B., Paulus, M., Krumholz, H. M., Krystal, J. H., & Chekroud, A. M. (2018). Association between physical exercise and mental health in 1·2 million individuals in the USA between 2011 and 2015: A cross-sectional study. The Lancet Psychiatry, 5(9), 739-746. doi:10.1016/s2215-0366(18)30227-x