Adderall vs. Phentermine for Weight Loss

If you're considering weight loss pills, you may be investigating phentermine versus Adderall. But these drugs are intended to be used for very different purposes, and misusing either can jeopardize your health.

In fact, it's not safe or recommended to use either medication unless your doctor prescribes it.

With that important stipulation in mind, here's what to know about phentermine versus Adderall when it comes to weight loss, including side effects and safety considerations to keep in mind if you're prescribed either drug.

Phentermine (also known as it's brand name, Adipex-P) is an FDA-approved, amphetamine-like prescription medication that's used to suppress appetite and promote weight loss, according to the Mayo Clinic.

Adderall is a prescription medication that combines amphetamine and dextroamphentamine to treat conditions like ADHD and narcolepsy, per the Mayo Clinic.

A common side effect of Adderall is weight loss, per the Mayo Clinic, so this medication is sometimes used off-label to help you shed pounds. However, it can be harmful to use drugs without the prescription and supervision of your doctor — in other words, taking Adderall for weight loss is not typically safe or recommended.

Phentermine is not like Adderall, meaning you can't take phentermine for ADHD. Its intended purpose is for weight loss, and it's been through rigorous FDA testing to support this use. Adderall, on the other hand, has only been approved to treat other conditions, and as a result, there may be unknown risks associated with using Adderall for weight loss.

Here's what Adipex does for weight loss: According to an April 2014 review in ​JAMA​, adults with obesity who took phentermine/topiramate (along with making lifestyle changes like eating a balanced diet and exercising) experienced up to 9 percent more weight loss than those who took a placebo medication.

The takeaway: Phentermine is the better choice if your goal is to shed pounds, and can be an effective prescription treatment if you have severe obesity.

Phentermine and Adderall can have side effects — here are some to keep in mind before taking either medicine as prescribed:

According to the Mayo Clinic, common Adderall side effects include:

• Anxiety
• Dry mouth
• Lack or loss of strength
• Stomach pain
• Weight loss

These side effects typically don't require medical attention, and should go away on their own as your body adjusts to the medication. However, you should seek medical care if you experience any of the following issues:

• Bladder pain
• Bloody or cloudy urine
• Frequent urge to urinate
• Difficult, burning or painful urination
• Fast, pounding or irregular heartbeat
• Lower back or side pain
  

Adderall is also one of the most commonly misused drugs, according to the Mayo Clinic. Taking Adderall for weight loss without a prescription is one example of this. And misusing the medicine can lead to a dependence or addiction.

It's also important to avoid this medicine if you're already taking (or have recently stopped taking) a class of antidepressants called MAO inhibitors, per the Mayo Clinic. Mixing the two could lead to more side effects.

Adipex can also cause side effects, per the Mayo Clinic. The most common are:

• Increased heart rate
• Tingling or prickling feeling in hands or feet
• Dry mouth
• Sleeplessness
• Nervousness
• Constipation

It's also best to avoid this medication if you have any of the following conditions, according to the Mayo Clinic:

• Heart disease
• High blood pressure
• Overactive thyroid
• You're pregnant or breastfeeding

Like Adderall, you should also avoid phentermine if you're taking or have recently stopped taking an MAO inhibitor, per the Mayo Clinic.

In the debate between Adipex versus Adderall for weight loss, Adipex wins because it is FDA-approved to help treat obesity.

But if you don't have severe obesity or your doctor doesn't recommend phentermine, you may not need to consider using Adderall versus Adipex at all. Instead, talk to your doctor about losing weight through lifestyle changes recommended by the National Health Service, including:

• Eating a balanced diet
• Getting plenty of fiber
• Exercising regularly
• Staying hydrated
• Cutting back on alcohol