Does Phentermine Cause Constipation?


Does Phentermine Cause Constipation?

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Phentermine is a prescription drug available in multiple forms, such as oral capsules, tablets, and orally disintegrating tablets. The brand name for this formula is Adipex p.

Phentermine is often used to treat obesity as a short-term remedy. Manufacturers advise using this drug with exercise, a low-calorie diet, and other factors that help in weight loss.

However, despite its benefits, some people have complained that it has certain side effects that are difficult to ignore. A few of them include diarrhea, headaches, dry mouth, vomiting, a bad taste in the mouth, etc. One that seems to come up fairly often, though, is constipation. In this article, we’ll explore whether Phentermine actually causes constipation.

How Does Phentermine Help in Weight Loss?

Phentermine hydrochloride is one of the members of anorectics. Anorectics are a drug class, and pharmacologists keep all the groups of medications that work similarly in one class. Moreover, they use these drugs to treat similar conditions.

Pharmacologists and dietitians still don’t know the working of Phentermine hydrochloride. The idea is that it works by releasing some chemicals from the brain to suppress appetite, which will make you eat less and lose weight easily.

Phentermine is an indirect-acting drug used to treat obesity. It stimulates the brain’s central nervous system. This part of the brain is responsible for high blood pressure and increased heart rate. Eventually, it will lead to decreased interest in eating. Moreover, Phentermine can also induce psychological and physical dependence in the consumer.

Phentermine was combined with topiramate in 2012, and FDA approved this drug combination for obesity and weight loss. The drug combination of Phentermine and topiramate stimulates the sympathetic nervous system to suppress your appetite while you burn calories in a resting position. Moreover, this drug therapy has shown additive efficacy in weight loss.

Side Effects of Using Phentermine to Lose Weight

Phentermine helps in weight loss by releasing chemicals that suppress your appetite. However, it comes with many side effects that prescribers and consumers should know beforehand.

Females who expose infants to Phentermine have an increased risk of orofacial clefts in their babies, which is a congenital malformation. This malformation usually occurs in the first trimester of pregnancy.

Other adverse effects include paraesthesia, dysgeusia, constipation, dizziness, insomnia, and dry mouth. In addition, Phentermine also interacts with the other medications you intake, which results in other side effects such as malignant hypertension, which means increased heart rate and blood pressure.

Serious Side Effects

Following is the list of serious side effects caused by using Phentermine. If you see any symptoms, you should call for a medical emergency and immediately reach your physician.

Primary Pulmonary Hypertension (Pph)

Primary pulmonary hypertension (PPH) is a type of high blood pressure harmful to your lungs’ arteries. It also affects the right side of the heart. The major symptoms of primary pulmonary hypertension are:

Heart palpitations – you will feel the increased heart rate and fluttering on the left side of the chest.DizzinessTrouble breathingFatigueCyanosis – a condition that is responsible for the bluish of lips and skinAngina – a famous term for chest pain around the heartEdema – a condition in which you will feel swelling around your legs and ankles.

Valvular Heart Disease

Phentermine may harm the valves of your heart which may not close properly and cause leakage. Its symptoms are similar to PPH:

  • Heart palpitations
  • Dizziness
  • Heart murmur
  • Fatigue and weakness
  • Angina Edema
  • Trouble breathing when you lie down
  • Arrhythmia – an irregular heartbeat

Other side effects might include:

  • Insomnia or trouble sleeping
  • Erectile dysfunction in men
  • Tremors (uncontrollable rhythmic movement in one part of your body)
  • Hypertension (high blood pressure)
  • Restlessness

Drug effects vary from person to person. Therefore, you don’t need to feel all these symptoms. Moreover, it is also not necessary that Phentermine must cause any side effects in your body. However, we have described the major and minor side effects that many patients have reported.

How Does Phentermine Cause Constipation?

Almost 50% of Phentermine users have reported constipation as one of the side effects of it, and it is the third most common adverse effect of Phentermine. Constipation is a lack of bowel movements and having problems while passing the stool.

Constipation occurs when someone does not have at least three bowel movements a week and has difficulty passing the stool. If you do not have almost three bowel movements a week, you should take remedies for constipation. However, the number of bowel movements per day or week varies from person to person.

Constipation results in different health conditions, such as a swollen abdomen, weight gain temporarily, nausea, etc. In addition, a constipated patient may suffer from vomiting and stomach pain, and it also causes problems in passing stool.

Phentermine suddenly changes a person’s workout routine and food intake habits; it suppresses appetite and increases energy. Moreover, the dramatic change in diet and exercise routines boosts the process of weight loss. Therefore, it results in many side effects, including constipation.

The water in the body is not enough to expel waste through stool and causes constipation. Furthermore, constipation may result from changes in routine, depression, increased stress levels, and anxiety. Decreased intake of food causes emotional changes, which may result in constipation.

Studies have shown that those who limit their diet to certain food groups may suffer from constipation. A low-carb diet such as keto or carnivore may decrease the intake of more fiber-rich foods like whole-grain resulting in constipation.

How Does Phentermine Hydrochloride Affect the Digestive System?

The chemicals from the brain also affect the digestive system by slowing down the peristalsis. Peristalsis is the active movement of the digestive system to intake food and digest it properly as the food moves down from the stomach to the intestine for the digestive process.

The slow peristalsis slows digestion and causes constipation, passing stool hardly. In addition, the chemical may cause dehydration in the body. Users do not intake adequate water, resulting in dry mouth, headache, and constipation.

How to Relieve Constipation Caused by Phentermine?

If you do not have a bowel movement for many days, you should immediately go for remedies to cure constipation, resulting in many adverse effects. Moreover, instead of using laxatives and other medications, we recommend you go for home remedies to cure constipation.

Following are some tips and remedies to cure constipation without visiting drug stores.

1. Drink Plenty of Water

Increased fluid intake is very helpful in relieving constipation. The body’s water depreciation causes fluid to pull from the stool, making it dry and hard to pass through the anus. Therefore, it is important to overcome dehydration by drinking at least eight glasses of water per day.

Avoiding energy drinks and other dehydrating liquids such as coffee, colas, and alcohol would be best. Rather you should take water and other calorie-free, caffeine-free drinks to avoid constipation.

You can also try to add lemon to the warm water and drink it in the morning to relieve constipation. Warm water helps tighten the intestines and increase bowel movements. Moreover, lemon is high in acid content and stimulates the digestive system to increase bowel movement. In addition, try to intake a natural laxative such as senna tea.

2. Take More Fiber-Rich Foods

If you suffer from constipation, try to add more fiber-rich foods to your diet. Fiber-rich foods help to treat and prevent constipation. However, there are two types of fibers: soluble and insoluble.

Soluble fiber lowers the cholesterol level in the blood flow while making it pass stool easily. At the same time, the insoluble fiber helps to regulate bowel movements. Furthermore, the daily fiber intake for a normal woman is 25 grams, and for a man, it is 38 grams.

You should remember that eating more fiber can worsen constipation if you do not intake fluids excessively. Therefore, ensure more water while you take fiber in your diet. Moreover, fiber-rich foods include whole fruit, vegetables with edible skins, legumes, whole grains, peas, beans, lentils, etc.

3. Focus on Aerobic Exercise

If you are suffering from constipation after taking Phentermine, try to focus on aerobic exercises more, such as walking, running, cycling, swimming, etc. A little gentle stretching and yoga can also help in getting rid of constipation.

Physical activities and a little exercise increase your blood flow toward the intestines, which keeps the abdominal muscle in shape and is also helpful in regular bowel movements. Therefore, aerobic exercises keep the stool moving. Moreover, exercise also helps you to reduce stress.

4. Try Prunes

Prunes or dried plums are helpful in the relief of constipation. It is rich in insoluble fiber and contains sorbitol, one of the natural laxatives. 80-120 grams or 10-14 prunes per day are good enough to cure constipation.

5. Try to Manage Stress

Stress, depression, and anxiety come with many risks, including mental and physical health. They also worsen constipation. Moreover, taking Phentermine can increase these emotions. Therefore, try to manage your workload.

You will lose weight while keeping your emotions stable because the human body does not function properly during stressful conditions. Moreover, effective stress management is also important for weight loss and relief from constipation.

6. Stool Softeners

Stool softeners are also available at drug stores to relieve constipation temporarily. They come in tablets, capsules, liquids, and syrups. Moreover, healthcare providers advise taking stool softeners at night before bedtime. However, you should not take these softeners for more than one week unless your doctor addresses you. This medication has many side effects, including nausea, stomach or intestinal cramps, throat irritation, rash, hives, vomiting, etc.

Does Phentermine Help in Losing Weight?

Phentermine is an amphetamine-like prescription that suppresses the appetite and boosts the weight loss process along with a controlled diet and exercise. It stimulates the CNS to release chemicals like dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline).

These chemicals increase heart rate, blood pressure, lack of appetite, sweating, and extra energy. Weight loss pills have Phentermine hydrochloride as an active ingredient, and it is a short-term treatment but leads to drug abuse.

Doctors’ prescription advises taking Phentermine for three months at one time. Phentermine dosage ranges from 8 – 37.5 milligrams. You can take low-potency tablets or capsules three times a day but high-potency tablets two times only.

Phentermine helps in weight loss and reaching a healthy BMI regardless of the possible side effects. Moreover, it is safe to take if you follow your doctor’s prescription and do as they address.


1. When Should You Visit the Doctor After Taking Phentermine?

When your body gets used to Phentermine, some side effects may go away alone without extra care or medication. However, if you notice that the side effects are worsening and not going away, you should visit your physician immediately.

They may change your dosage of Phentermine or even treatment. Moreover, if you feel heavy in your chest, have difficulty breathing, or have chest pain or swelling in the ankles after taking Phentermine, you should call the medical emergency immediately and go for treatment.

2. Is Phentermine Safe to Consume?

Phentermine taken according to the doctor’s prescription is safe and helps with weight loss. However, the effects vary from person to person. Therefore, if you feel any side effects, go to the doctor immediately.

3. What Is the Treatment Duration of Phentermine?

You should take Phentermine for three months at least. However, some doctors prescribe the medicine for longer or ask to take the course again after a few months. But these are individual cases and are not applied to everyone. Therefore, always take Phentermine as the doctor addresses.

4. Is Constipation from Phentermine Curable?

Constipation is curable by natural laxatives, home remedies, and stool softeners. You can choose any of them that helps you eliminate constipation that occurs because of Phentermine.

5. Who Should Take Phentermine?

Phentermine is only available under the doctor’s prescription. Persons with BMI greater than or equal to 30 kg/m2 should take this medicine as their BMI is in the obese range. Moreover, people with a BMI of 27-29.9 kg/m2 and suffering from type 2 diabetes, high cholesterol, or controlled hypertension can also take Phentermine.

In addition, people with cardiovascular disease and addiction history should avoid this medicine.


Phentermine is an active ingredient in weight loss pills. It suppresses the appetite, boosts energy and calorie expenditure while resting, and increases heart rate.

Along with the benefits of weight loss, Phentermine has many side effects that you should know before taking the Phentermine. The common side effects of Phentermine are Primary pulmonary hypertension (PPH), heart palpitations, dizziness, shortness of breath, tiredness, cyanosis, angina, Edema, and Valvular heart disease.

This article covers details of the side effects of Phentermine, especially constipation. Moreover, the common side effects include constipation, insomnia or trouble sleeping, erectile dysfunction in men, tremors, hypertension (high blood pressure), and restlessness.

In addition, the article guides about how to get relief from constipation caused by Phentermine. You can get all the tips and remedies to cure constipation, including natural laxatives and stool softeners.