Phentermine is not suitable for individuals with a history of heart disease, high blood pressure, an overactive thyroid, or glaucoma. It is also contraindicated during pregnancy, breastfeeding, and in those with a history of substance abuse.
Good to know: Phentermine isn't recommended if you have a history of heart disease. But Wegovy, a newer weight-loss medication, may lower your risk of heart problems in addition to helping you lose weight. So it's likely a better option than phentermine if you have a history of heart problems.
Phentermine is one of the most prescribed weight-loss medicines. But it isn't a good choice for people with heart disease, high blood pressure, an overactive thyroid gland or glaucoma. It also isn't for people who are pregnant, may become pregnant or are breastfeeding.
Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat. Difficulty with paying attention, memory, or speech. Fast or irregular heartbeat. Fever that does not go away, decreased sweating.
Check with your doctor right away if you have chest pain, decreased ability to exercise, fainting, swelling of the feet or lower legs, or trouble breathing. This medicine may cause some people to become dizzy, lightheaded, or less alert than they are normally.
Rare but serious phentermine side effects include:
Dangerously high blood pressure or heart rate. Pulmonary hypertension (a rare lung condition) Damage to the heart valves.
If you have well-controlled high blood pressure, Ozempic may be the safer choice as it doesn't raise blood pressure and might even help lower it slightly. Phentermine can raise blood pressure and heart rate in some people and is contraindicated if you have uncontrolled hypertension.
Stop taking phentermine and get help right away if you have any of the following symptoms of a serious allergic reaction.
There were no interactions found between Benadryl and phentermine. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.
Yes, many women report changes in period frequency, flow, and timing while taking phentermine. These include lighter or heavier periods, late or missed periods, or irregular cycles. These changes are usually due to weight loss and hormonal shifts.
Administer before breakfast or one-to-two hours after breakfast. Avoid late evening administration as this may cause insomnia. Some people may benefit from a twice-daily dosage regimen. Your doctor will decide the appropriate dosage for you.
Phentermine is FDA-approved to help with weight loss in adults with a BMI of 30 or more, or a BMI of 27 or more with other risk factors like high blood pressure, high cholesterol, or diabetes.
It's not a good idea to eat too little while on phentermine, as it may result in malnutrition. Be sure you are getting the appropriate nutrients through a well-balanced diet. This drug is an appetite suppressant.
If you have severe liver disease you might not be able to take weight loss medication. You might need to temporarily stop taking weight loss medications if you're going to have an operation. You should not take weight loss medication if you are pregnant of breastfeeding.
The first and only FDA-approved GLP-1 pill for weight loss. Find out how Wegovy® pill, along with a reduced calorie diet and increased physical activity, can help adults with obesity or some adults with excess weight (overweight) who also have weight-related medical problems to lose weight and keep it off.
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
Phentermine reduces your appetite, but it doesn't automatically ensure you're eating fewer calories than your body burns. If you're still consuming too many calories, especially from high-sugar or processed foods, you may not lose weight, even with the medication.
There were no interactions found between phentermine and Vitamin D3. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.
While phentermine does not directly burn fat, it can indirectly support fat loss. By reducing appetite and calorie intake, phentermine can lead to the utilization of stored fat for energy. Some evidence suggests it might modestly impact metabolic rate as well.
Withdrawal symptoms can include:
Case reports indicated that the use of phentermine in patients with bipolar disorder may lead to manic or hypomanic episodes,28-31) and the report of Allison et al. 33) suggested that phentermine may induce or aggravate depression in some patients.
Some of the ways she's lost weight include walking, eating more protein, and medication to help with how her body processes food. Clarkson started some of these changes to her diet and exercise routines when she moved to New York City, where she hosts "The Kelly Clarkson Show."
Key Takeaways
The new FDA-approved weight loss drug Zepbound (tirzepatide) may be the strongest weight loss drug available. Zepbound is a once-weekly injectable medicine. Qsymia may be a stronger weight loss pill than phentermine since Qsymia contains both phentermine & topiramate, which both cause decreased appetite.
But about half of people with obesity on this class of medications, called glucagon-like peptide agonists or GLP-1s, stop taking it within a year. Studies suggest that most people discontinue their use due to the high cost and adverse gastrointestinal side-effects.