Can You Take Phentermine With Metformin?

What is Phentermine?

Phentermine is a sympathomimetic amine often used for short-term weight loss. It is an appetite suppressant designed to combat obesity by decreasing appetite and increasing satiety.[1].

Phentermine is approved for “short-term” treatment of patients with obesity [2]. It is effective in promoting weight loss when combined with other drugs, such as topiramate [3, 4, 5]. However, it’s important to note that Phentermine should not be used with certain other medications due to the risk of severe side effects [3].

What is Metformin?

Metformin is a medication used to treat type 2 diabetes and prediabetes. It works by decreasing the amount of glucose your liver releases and increasing your body’s response to insulin. Metformin is also used in combination with other medications to treat polycystic ovary syndrome (PCOS) [4].

Metformin is commonly prescribed to manage type 2 diabetes. Metformin is used daily by 150 million people worldwide [5]. Recent studies have also suggested that metformin may have additional medical benefits beyond treating diabetes, revealing its potential therapeutic uses [6].

Can Phentermine and Metformin be taken together?

The question of whether Phentermine and metformin can be taken together is a valid one, especially for patients who are dealing with both obesity and diabetes.

Taking Phentermine and Metformin together may cause a significant drop in your blood sugar levels [7]. This could lead to hypoglycemia, a condition characterised by abnormally low blood sugar levels, which can cause symptoms such as dizziness, confusion, and, in severe cases, loss of consciousness.

In conclusion, while Phentermine and metformin can interact with each other, they can still be taken together under careful medical supervision. Always consult with your healthcare provider about potential interactions with all prescription drugs, vitamins, herbs, supplements, and over-the-counter medicines that you are taking [7].

Phentermine vs Metformin: Side effects

Side effects of Phentermine

Mild side effects include restlessness, intense excitement or happiness, feeling uneasy, trouble sleeping, nausea, dizziness, tremors, diarrhoea, dry mouth and tongue, bad taste in your mouth, constipation, and headaches [8].

More severe side effects can include heart palpitations, chest pain, increased heart rate, increased blood pressure, and even rare conditions like valvular heart disease and pulmonary arterial hypertension (PAH) [8].

Side effects of Metformin

Common side effects include:

  • heartburn,
  • stomach pain, nausea or vomiting,
  • bloating, gas, diarrhoea, or constipation
  • weight loss, and a metallic taste in your mouth [9].

Metformin can cause digestive disorders such as diarrhoea and vomiting in around 30% of patients [10].

It’s important to note that these side effects can vary from person to person, and not everyone will experience them. If you take either of these medications and are concerned about side effects, speaking with your healthcare provider is best.