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The Skinny on Weight Loss Drugs: Can Prescriptions Actually Work?

by Dr. Sharon Orrange on June 15, 2015 at 3:49 pm

Many Americans struggle with their weight. More than two-thirds of American adults are considered overweight, and one-third are obese. Obesity-related illness is estimated to cost the American economy almost $200 billion a year.

Sadly, there isn’t yet a perfect pill to end obesity. However, there are a variety of prescription options to help you jump-start your weight loss, with a number of new drugs approved in just the past few years.

These new drugs are welcome additions, not just in the fight against obesity, but in helping diabetics and pre-diabetics where treatment is also focused on weight loss.

Most of the following prescriptions are only for short-term use, but they can help you be successful in losing weight when used along with diet and exercise. What is considered a success? Losing 5 to 10 percent of your baseline weight in 6 months.

With all the medications and injections now available, how can you tell which ones are the real deal? These are five weight loss interventions that really can work.

1.  Phentermine (Adipex-P) is a short-term weight loss medication, used 12 weeks on average. Phentermine is a sympathomimetic, meaning it works like a stimulant to suppress appetite.

  • Pros:
    • It’s been around since 1959 so the safety profile is well known. It’s your old school option.
    • It’s cheap, available as generic phentermine. The usual starting dose is half a 37.5 mg tablet once daily in the morning, increasing to a full tablet if you don’t encounter side effects. There is also a brand-name phentermine, Adipex-P, also dosed at 37.5 mg once daily.
    • It works. After 24 weeks people lost on average 3.6 kg (a little under 8 pounds) more of their body weight compared to placebo.
  • Cons:
    • Dry mouth is one of the most common reported side effects.
    • High blood pressure may be another side effect, though studies show the effects of phentermine on blood pressure are minimal.

2.  Belviq (lorcaserin) is a serotonin receptor agonist approved in 2012.

  • Pros:
    • Belviq is taken 10 mg twice daily, independently of meals.
    • In contrast to some of the other options, titration isn’t required—you don’t need to step up from a starting dose.
    • After a year, people taking Belviq had seen a 5.8 percent weight loss (a 10 pound loss if you weigh 160 pounds). That loss was sustained during the follow-up year.
    • Blood pressure and sugars were lower in those taking Belviq.
  • Cons:
    • Headache is the most common side effect of Belviq, occurring in 16 percent of patients taking it.
    • Cost. Belviq is brand-name only, and expensive. However, the manufacturer does offer coupons which can help offset some of the cost.

3. Contrave (naltrexone/bupropion) is a new combination opioid receptor antagonist and catecholamine reuptake inhibitor that was approved in September 2014.

  • Pros:
    • At the end of a year, people taking Contrave have seen a 5 to 8 percent weight loss.
    • Contrave improved hemoglobin A1c, triglycerides, and HDL (the “good cholesterol”) in people with diabetes.
    • Because it contains an antidepressant (bupropion), folks taking Contrave reported less depression than those taking placebo. That’s a plus.
  • Cons:
    • Nausea and constipation, which is why you start low and titrate up with Contrave.
    • Cost. Same deal as Belviq: it’s brand-name only and rarely covered by insurance. The manufacturer also offers coupons which can help offset the cost.

4. Saxenda (liraglutide) is a higher dose of the diabetes medication Victoza. Saxenda was approved in December 2014 as the first GLP-1 analogue for long-term weight management.

  • Pros:
    • Saxenda is injected rather than taken orally, and only used once daily.
    • People using Saxenda lost 8 percent  of their body weight compared to 2 percent in the placebo group. For example, if you weigh 160 pounds that’s a 13 pound loss.
    • Saxenda has been shown to lower blood sugar, triglycerides, systolic blood pressure, and other cardiac risk factors.
  • Cons:
    • Mild nausea is frequent at the beginning of Saxenda therapy, reported in almost 40 percent of people taking it. This is why you titrate up to the 3 mg dose over 4 weeks.
    • Low blood sugar occurred more often in people using Saxenda (23 percent vs 13 percent in the placebo group).
    • Saxenda is an injection, so if you hate injections this is not for you.
    • Cost. Saxenda is a very expensive brand-name drug—currently over $1,000 on GoodRx for a typical 30-day supply.

5.  Kybella (deoxycholic acid)—you may have read about this new “double-chin injection” recently. This drug is brand new, and could be a game changer. Kybella is a fat-reducing injectable, not a pill. When injected into subcutaneous fat it results in the destruction of fat cells. Kybella has just been approved for contouring the submental area (the area under the chin) by reducing fat in that location.

  • Pros:
    • Due to changes in our face as we get older, the fat of the jowl is revealed. This leads to the characteristic “turkey neck.” Kybella is the first nonsurgical option for getting rid of this.
    • Kybella works. A large proportion of patients (68 percent) treated with Kybella report increased satisfaction with appearance of their face and chin.
    • Early studies show it’s safe, with minimal discomfort after therapy.
  • Cons:
    • It’s so new—you might want to sit back and let it be out there for a few months before considering this option.
    • Cost. Kybella just received FDA approval but I’m guessing it will be pricey.
    • Availability. Kybella has been approved by the FDA, but is not yet available. The launch is expected later in June 2015, and you may be able to receive the injection from your doctor within a few months.


Two additional prescription options exist, but there are issues. Real issues.

  • Orlistat is available as prescription Xenical or over-the-counter Alli in a lower dose. Orlistat reduces fat absorption by 30 percent and does result in some weight loss, but the side effects of fecal incontinence and diarrhea are intolerable to most. My patients can’t stand taking this medication.
  • Qsymia (phentermine/topiramate) is cumbersome to get, and to take. Due to the risk of birth defects from topiramate, the FDA imposed a Risk Evaluation Management Strategy (REMS) program on Qsymia. This means it is only available through certified pharmacies which ensure you are aware of the risk and take appropriate precautions. There are also guidelines on how to titrate and when to stop using Qsymia—it can’t be stopped abruptly.

Keep this in mind as well: except for phentermine, all of the drugs above are brand-name prescriptions that are not usually covered by insurance. If you and your doctor find an option that works for you, take advantage of GoodRx and coupons offered by the drug companies for more affordable prices.

Dr O.

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