What Is Phentermine? 

Phentermine, often sold under the brand names Adipex-P, Oby-Cap, T-Diet, Lomaira, or Zantryl, is a stimulant which acts on the central nervous system (similar to an amphetamine) to suppress appetite. First developed in 1959, Phentermine has been prescribed to patients who generally have a medical need to keep their weight down (particularly obese patients with comorbidities). Phentermine is used as an appetite suppressant for short-term weight loss programs—it’s typically only prescribed for a four-to-six-week duration. When combined with a low-calorie diet, daily exercise regimens, and behavioral changes, Phentermine can result in quick weight loss.

Benefits of Phentermine

Phentermine is used as a weight loss medication due to its ability to reduce hunger and caloric intake while instilling a feeling of fullness. Doctors usually recommend a Phentermine weight loss plan for patients with obesity or individuals with certain health risks linked to being overweight, like high blood pressure, high cholesterol, and diabetes. Because they’re primarily used to lose weight, Phentermine diet pills can also minimize susceptibility to weight-related medical problems such as heart failure, heart disease, stroke, gout, certain types of cancer, and cardiovascular disease.

Research proves the effectiveness of Phentermine and its ability to speed up weight loss—the average expected weight loss when using Phentermine is 5% of your initial body weight over a four-to-six-week duration. If you take Phentermine for an extended 12-week program, you can lose up to 10% of your initial body weight (about 10-20 pounds for a 200-pound person).

Is Phentermine Safe?

Phentermine is only considered safe to use on a short-term, doctor-supervised basis. It is a controlled substance, and you should discuss any preexisting medical conditions with your physician before taking it. You are not considered a good candidate for a Phentermine diet plan if you have heart disease, uncontrolled high blood pressure, an overactive thyroid, allergies to stimulants or appetite suppressants (like amphetamine or diethylpropion), mental or mood disorders (like anxiety, bipolar disorder, or depression), or have a history of substance abuse.

It’s crucial to discuss all medications you are currently taking with your doctor to ensure there are no adverse drug interactions when you begin taking Phentermine. You should be especially cautious when taking Phentermine if you have diabetes, as you may need to adjust your diabetes medication during treatment if your doctor advises. The medication should not be used during pregnancy, and you should stop taking it immediately if you think you may be pregnant. If you use Phentermine longer than directed, you are at a higher risk for developing serious health problems, including heart palpitations, dizziness, edema, shortness of breath, primary pulmonary hypertension, and valvular heart disease.

Side Effects of Phentermine 

Phentermine usage must be closely monitored by a doctor to avoid complications, but many individuals who take this medication do not experience serious side effects. Common side effects of Phentermine usually go away within a few days of beginning the prescription, but if they persist, you should talk to your doctor. Some common side effects of Phentermine may include:

  • Constipation
  • Bad taste in your mouth
  • Diarrhea
  • Dry mouth
  • Headache
  • Vomiting
  • Restlessness
  • Insomnia

Phentermine FAQs

How to Get Phentermine

Phentermine is a class IV drug and must be prescribed by a doctor. Simply talk to your health care provider about your weight loss goals to receive a prescription with dosages tailored to your unique goals.

Does Diet Doc Prescribe Phentermine?

Our doctors do not prescribe Phentermine at this time. See the weight loss medications we do offer to learn about alternatives.

What is the right Phentermine dosage?

Your doctor will determine the proper dosage and duration of your Phentermine prescription. This medication is an oral tablet usually taken once a day before breakfast. Depending on your unique needs and health conditions, your doctor may adjust your dosage to three smaller doses each day. Taking this medication late in the afternoon may interfere with your ability to sleep. 

Can you drink alcohol while taking Phentermine?

Drinking alcohol while taking Phentermine can increase your risk of side effects like dizziness, headaches, dry mouth, constipation, diarrhea, anxiety, and trouble sleeping. Talk to your doctor about your specific alcohol consumption while taking Phentermine.

Is Phentermine speed?

No, Phentermine is not speed. Phentermine is considered a sympathomimetic drug, and it works as a stimulant in the central nervous system to decrease appetite.

Does Phentermine work?

Yes, Phentermine works. Clinical studies show that taking Phentermine for a short period of time, in combination with diet, exercise, and behavior changes, can lead to weight loss. 

What drug class is Phentermine?

Phentermine is a schedule IV drug due to its potential for abuse and its addictive effects. However, the actual potential for Phentermine abuse is low. Talk to your doctor before starting Phentermine if you have previous substance abuse issues. 

How long can you take phentermine?

Your doctor will determine the appropriate duration of your Phentermine prescription. Typically patients take Phentermine for four to six weeks, while the longest recommended duration for taking phentermine is 12 weeks.

How does Phentermine cause weight loss?

Researchers aren’t exactly sure how Phentermine is able to suppress the appetite, but its effectiveness has allowed patients to more easily restrict calories in order to speed up short-term weight loss. It works as a stimulant to decrease hunger and instill a feeling of fullness, reducing appetite and leading to weight loss.

Does Phentermine cause depression?

Side effects of Phentermine can include anxiety and restlessness. You should not take Phentermine if you have a history of mental illness, such as depression. Don’t take Phentermine if you are currently taking other medication to treat mental illness.

Disclaimer: The statements made regarding these products have not been evaluated by the Food and Drug Administration. The efficacy of these products has not been confirmed by FDA-approved research. These products are not intended to diagnose, treat, cure or prevent any disease. All information presented here is not meant as a substitute for or alternative to information from healthcare practitioners. Please consult your healthcare professional about potential interactions or other possible complications before using any product. The Federal Food, Drug, and Cosmetic Act requires this notice.