Can overcoming obesity be as simple as taking a pill? Prescription weight-loss pills aren’t a magic bullet. But when used with a healthy diet, restricting calorie intake, and exercise, they could help some people on their weight loss journey.

We also eat lots of high-calorie foods and have 24-hour access to our diet. All of this promotes weight gain. Weight loss drugs help us overcome some of this physiology and control our appetite for weight loss. So what is the best weight loss drug? Please read to find out.

Some FDA-approved weight-loss medications

Prescription medications to manage obesity work in different ways—some work by targeting areas of the brain that regulate appetite. By altering certain brain chemicals, these drugs act as appetite suppressants and increase feelings of fullness. Some medicines use a different pathway, helping to interfere with your body’s absorption of fat. Because obesity can be a chronic health issue, many of these drugs are meant to be used long-term, even after you reach your ideal weight—assuming you’re responding to the medication in the first place.

Currently, only a handful of weight-loss medicines are approved by the Food and Drug Administration (FDA). The most commonly used ones include the following.

Adipex (phentermine)

Phentermine is the most commonly prescribed weight-loss medication used in this country. It helps suppress appetite and makes you feel fuller for longer. Phentermine is an amphetamine-like stimulant drug that can affect your heart. As such, it’s generally used for the short term (usually 12 weeks at a time).

Side effects may include:

  • Shortness of breath
  • Chest pain
  • Increased blood pressure
  • Increased heart rate/pounding heart
  • Changes in mood
  • Itchiness

According to the drug’s FDA prescription information, certain people should not use the drug, including:

Those with cardiovascular disease (including uncontrolled high blood pressure)

People who have taken MAO Inhibitors —a type of drug that’s sometimes used to treat depression within 14 days

  • Pregnant or nursing women
  • People with glaucoma
  • Those with an overactive thyroid

People who have mood disorders, incredibly manic/depressive moods, or agitation

Phentermine (Qsymia/topiramate)

Qsymia is a medication that combines a low dose of phentermine with topiramate, a drug used to treat seizures and migraines.

Qsymia comes in a variety of dosages.

For the first two weeks, your provider will prescribe a dose of 3.75/23 mg (3.75 mg of phentermine, 23 mg of topiramate) taken in capsule form once a day.

You’ll be prescribed a 7.5/46 mg capsule starting in week three. You’ll stay on this dose indefinitely if you’ve lost at least 3% of your overall body weight by 12 weeks.

Qsymia may cause some of the same side effects. The most common ones include:

Tingling or numbness in hands, feet, arms, and face

  • Dry mouth
  • Constipation
  • Trouble sleeping
  • Dizziness
  • Changes in the way food tastes

Saxenda (liraglutide)

The active ingredient in Saxenda is a class of drugs used to treat Type 2 diabetes and keep blood sugar levels in check.

Saxenda is a daily injectable with dosing increasing from 0.6 mg in week one to 3.0 mg by week five. While Saxenda can cause some severe side effects, such as inflammation of the pancreas (called pancreatitis), gallbladder problems, and mood changes, the most common side effects include:

  • Nausea
  • Diarrhea
  • Constipation
  • Vomiting
  • Low blood sugar (hypoglycemia)
  • Headache
  • Dizziness
  • Tiredness
  • Stomach pain

Saxenda carries a black box warning (the FDA’s strongest alert to consumers and healthcare providers about severe side effects) because animal studies have linked liraglutide and medicines like it to certain thyroid tumors and thyroid cancer.

You must not use Saxenda if you have had these conditions or have a family history. Saxenda isn’t appropriate for pregnant or nursing women. Talk to your healthcare provider if you’re taking medicines that act like GLP-1 receptor agonists. Because Saxenda can slow stomach emptying, you must ask your doctor how that may affect other prescription and over-the-counter drugs you take.

Contrave (naltrexone and bupropion)

Contrave combines naltrexone (used to treat substance abuse) and bupropion (an antidepressant marketed under Wellbutrin). It’s thought to work on the brain to regulate appetite and cravings.

Like a lot of weight-loss medications, your dose of Contrave will start low and increase over time.

Week one: One pill in the morning.

Week two: Two tablets, one in the morning and the other at night.

Week three: Two tablets in the morning and one in the evening.

Week four and beyond: Four capsules per day—two in the morning, two in the evening

Contrave can potentially produce serious side effects, such as suicidal thoughts and seizures, but the most common side effects are:

  • Nausea
  • Constipation
  • Headache
  • Vomiting
  • Dizziness
  • Trouble sleeping
  • Dry mouth
  • Diarrhea

People should avoid Contrave if they have:

  • Have seizures
  • Are pregnant
  • Use other drugs containing bupropion
  • Are withdrawing from alcohol and certain other drugs
  • Have used an MAOI within 14 days

Plenty

Plenty is technically a medical device, not a medication. It’s a capsule that contains superabsorbent hydrogel particles. When the tablet is swallowed, the particles are released, helping to fill up to one-fourth of the stomach. With the stomach at least partially complete, you’re apt to eat less.

The most common side effects are:

  • Bloating
  • Abdominal pain
  • Flatulence

Plenty is not approved for use in those under the age of 22. You also shouldn’t take it if you’re allergic to citric acid, cellulose, gelatin, and other gel ingredients.

Xenical

Orlistat is a lipase inhibitor, which blocks the enzyme that helps absorb some of the fats in the foods you eat. This means that less fat you consume makes it into fat cells to become stubborn belly fat. Orlistat has two strengths—an over-the-counter 60mg strength marketed as Alli and a prescription strength (120mg) sold as Xenical.

Xenical is taken by mouth three times a day, within or within one hour of a meal that contains fat.

Xenical is not as effective as some other weight-loss prescriptions.

People who should avoid Xenical:

  • pregnant or breastfeeding
  • Have gallbladder problems
  • Have food absorption issues

Xenical can affect the absorption of not just fat but also vitamins from the foods you eat.

Wegovy

Wegovy is the newest FDA-approved weight-loss medication and works much the same way as Saxenda, by mimicking the action of the hormone GLP-1 to suppress hunger.

Dosage is increased over several weeks to months until a 2.4 mg dosage is achieved.

Some of the most common side effects include:

  • Nausea
  • Constipation
  • Vomiting
  • Stomach pain
  • Indigestion
  • Headache
  • Fatigue
  • Low blood sugar (if you have Type 2 diabetes)

Safety information

Prescription weight-loss drugs can be effective, but they aren’t risk-free. While most side effects are mild, some can be very serious and vary based on the drug and the person using it.

  • An increased heart rate that doesn’t slow down
  • Shortness of breath
  • Kidney stones
  • Seizures
  • Low blood sugar
  • All-over severe stomach pain (this could signal pancreatitis)

Of course, your physician should be monitoring you while you’re on the medication, but if something is worrying you, reach out.

What is the best prescription weight loss drug for you?

Now for a million-dollar question: Given the options, what is the best diet pill based on safety and efficacy? There is no best answer.

These medications should be combined with natural weight loss strategies such as diet and exercise for best results.

Some health tips to help you achieve a healthy weight

Eat high fiber, high protein foods to feel happier. Consider a low-carb, low-fat diet or limit processed carbohydrates (white bread, candies, and pasta). Focus on a plant-based diet. Studies have shown that it is effective in weight loss and is rich in healthy antioxidants. Instead, aim to make 80% to 90% of what you eat healthily.

Do regular exercise to burn calories, decrease body fat, boost metabolism, and increase muscle mass. And stay away from any pill or herbal remedy that claims to be the best weight-loss supplement, such as:

  •  Green coffee bean extract
  •  Konjac (a root)
  •  L-carnitine (an amino acid derivative)
  •  Green tea extract

While these dietary supplements might claim to promote fat loss and fat burning and help you lose weight, well-conducted scientific studies don’t always bear this out. What’s more, these diet supplements are not regulated by the FDA, so you can’t be sure exactly what’s in them. Even some natural ingredients at certain levels can be toxic to some people.