Category Archives: Weight-Loss Drugs

New Weight-Loss Drug: Tirzepatide

Here’s the evidence at New England Journal of Medicine for tirzepatide for weight loss. It is a once-weekly injection. Cost? Unknown to me.

At baseline, the mean body weight was 104.8 kg, the mean BMI was 38.0, and 94.5% of participants had a BMI of 30 or higher. The mean percentage change in weight at week 72 was −15.0% (95% confidence interval [CI], −15.9 to −14.2) with 5-mg weekly doses of tirzepatide, −19.5% (95% CI, −20.4 to −18.5) with 10-mg doses, and −20.9% (95% CI, −21.8 to −19.9) with 15-mg doses and −3.1% (95% CI, −4.3 to −1.9) with placebo (P<0.001 for all comparisons with placebo). The percentage of participants who had weight reduction of 5% or more was 85% (95% CI, 82 to 89), 89% (95% CI, 86 to 92), and 91% (95% CI, 88 to 94) with 5 mg, 10 mg, and 15 mg of tirzepatide, respectively, and 35% (95% CI, 30 to 39) with placebo; 50% (95% CI, 46 to 54) and 57% (95% CI, 53 to 61) of participants in the 10-mg and 15-mg groups had a reduction in body weight of 20% or more, as compared with 3% (95% CI, 1 to 5) in the placebo group (P<0.001 for all comparisons with placebo).

Three to 7% of users stopped the drug due to side effects.

Click for a Diabetes Daily article about the drug.

Steve Parker, M.D.

PS: I can help you lose weight without drugs!

Weight-Loss Pill Plenity: Does It Work?

“With this raging inflation, I may need to cut back on food and beer.”

Dr Harriet Hall wrote a brief review of the new weight-loss drug Plenity at Science-Based Medicine. Her conclusion:

So far, effectiveness has been shown in only one placebo-controlled trial. Diet and exercise must be continued. It doesn’t work well for everyone: 6 out of 10 users lost at least 5% of their body weight; the other 4 didn’t. It appears to have fewer side effects than other weight loss products. Not a way to achieve ideal weight, but probably worth trying for patients who understand that it is only an aid and not a final solution. I hope they will be encouraged enough by a 22-pound weight loss to continue losing weight with or without Plenity.

Steve Parker, M.D.

PS: Overweight or obese? I can help. No pills or surgery needed.

Weight-Loss Drugs: Semaglutide Versus Liraglutide

How much does it cost?

Semaglutide and liraglutide are drugs that were developed to treat diabetes and are FDA-approved for that. They are given by subcutaneous injection. Semaglutide is also FDA-approved for weight loss in non-diabetics if certain conditions are met.

Once-weekly semaglutide outperformed daily liraglutide in overweight and obese non-diabetics.

From JAMA Network:

Question  Among adults with overweight or obesity without diabetes, what is the effect of once-weekly subcutaneous semaglutide, 2.4 mg, vs once-daily subcutaneous liraglutide, 3.0 mg, on weight loss when each is added to counseling for diet and physical activity?

Findings  In this randomized clinical trial that included 338 participants, mean body weight change from baseline to 68 weeks was –15.8% with semaglutide vs –6.4% with liraglutide, a statistically significant difference.

Meaning  Among adults with overweight or obesity without diabetes, once-weekly subcutaneous semaglutide, compared with once-daily subcutaneous liraglutide, added to counseling for diet and physical activity resulted in significantly greater weight loss at 68 weeks.

For prevention or improvement of overweight- and obesity-related illnesses, aim for loss of at least 5 to 10% of body weight. Assuming you’re overweight or obese in the first place. 16% body weight change is significant. 16% of 300 pounds (136 kg) would be 48 pounds (22 kg).

Steve Parker, M.D.

PS: Needle-phobic? Try this instead:

Stop Taking Lorcaserin: Drug Linked to Cancer

Don’t blame her

From the U.S. Food and Drug Administration:

ISSUE: FDA has requested that the manufacturer of Belviq, Belviq XR (lorcaserin) voluntarily withdraw the weight-loss drug from the U.S. market because a safety clinical trial shows an increased occurrence of cancer. The drug manufacturer, Eisai Inc,. has submitted a request to voluntarily withdraw the drug. When FDA approved lorcaserin in 2012, we required the drug manufacturer to conduct a clinical trial to evaluate the risk of cardiovascular problems. A range of cancer types was reported, with several different types of cancers occurring more frequently in the lorcaserin group, including pancreatic, colorectal, and lung.

BACKGROUND: In January 2020, FDA announced we were reviewing clinical trial data and alerted the public about a possible risk of cancer associated with lorcaserin based on preliminary analysis of the data.

RECOMMENDATION: PatientsPatients should stop taking lorcaserin and talk to your health professionals about alternative weight-loss medicines and weight management programs.

Source: Belviq, Belviq XR (lorcaserin) by Eisai: Drug Safety Communication – FDA Requests Withdrawal of Weight-Loss Drug | FDA

I never prescribed lorcaserin.

Steve Parker, M.D.

Click pic to purchase at E-book versions also available at

Are Low-Carb Diets More Effective Than Others?

DietDoctor Andreas Eenfeldt has a list of 16 scientific studies suggesting the superiority of low-carb diets for weight loss. I hope he keeps updating it. Here it is.

For my version of a low-carb diet, see KMD: Ketogenic Mediterranean Diet or Advanced Mediterranean Diet (2nd Ed.). The latter book also has a traditional “balanced” calorie-controlled diet with greater variety than a very low-carb diet. Ketogenic diets are getting a boost recently from Dr. Georgia Ede, Dr. Peter Attia, and the Livin’ La Vida Low-Carb Man, Jimmy Moore.

Steve Parker, M.D.

FDA Approves Qsymia for Weight Loss

“These are flying off the shelves!”

On July 17, 2012, the U.S. Food and Drug Administration approved the combination of phentermine and topiramate for weight loss and management.  They will be marketed in the U.S. as Qsymia.  Don’t ask me how to pronounce it.

The drugs individually had been approved by the FDA years ago for other purposes, so we already know a lot about them.  If memory serves me, phentermine alone is FDA-approved for weight loss, but only for up to 12 weeks.

The press releases from the FDA and Vivus, Inc., don’t say how long the combo drug can be used.  I’m guessing up to one year since that’s how long the clinical trials lasted.

Who Can Take Qsymia?

Obese adults with a body mass index 30 or higher.  Or overweight adults with BMI 27 or higher if they have one or more weight-related condition such as high blood pressure, type 2 diabetes, or high cholesterol.

You Should NOT Take Qsymia If You Have or Are:

  • Pregnant
  • Glaucoma
  • Overactive thyroid
  • Recent stroke
  • Recent unstable heart disease

If I Take the Pill, Do I Still Have to Exercise and Watch My Calories?


What’s the Dose?

Phentermine 7.5 mg and topiramate 46 mg daily.  A double strength pill (15 + 92 mg) is available for select patients.

Final Thoughts

Lorcaserin (Belviq) is a weight loss drug approved by the FDA within the last month.  These are the first new weight loss drugs on the U.S. market since 1999.

Abbott voluntarily withdrew Meridia (sibutramine) from the U.S. market in 2010 due to concern about it causing heart attacks and strokes.

In 2008, the European Medicines Agency withdrew prescription-writing for the weight-loss drug rimonabant, citing concern about psychiatric side effects.

Between 1997 and 2007, five weight-loss drugs were removed from various markets around the world due to safety or effectiveness considerations: phenylpropanolamine HCl, dexfenfluramine HCl (e.g., Redux), fenfluramine HCl (Pondimin), diethylpropion HCl (Tenuate), and phentermine HCl (e.g., Ionamin).

It’s unknown whether weight-loss drug therapy reduces the morbidity and mortality of obesity over the long run.

I’ll wait at least two or three years before giving these new drugs to my patients—I’ve seen too many drugs withdrawn from the market because of adverse effects showing up years after drug approval.

Without permanent changes in lifestyle, lost weight is likely to return after you stop taking any weight-loss pill.

Clearly, drugs are no panacea.

Steve Parker, M.D.

First New Weight-Loss Drug in a Decade: Lorcaserin Hydrochloride

The U.S. Food and Drug Administration today approved lorcaserin hydrochloride as a weight-loss drug, according to MedPage Today.

The drug, to be sold as Belviq in the U.S., is an activator of the serotonin C2 receptor in the brain.  This may reduce food consumption by producing early satiety at mealtime.

According to the FDA’s press release, “the most common side effects of Belviq in non-diabetic patients are headache, dizziness, fatigue, nausea, dry mouth, and constipation, and in diabetic patients are low blood sugar (hypoglycemia), headache, back pain, cough, and fatigue.”

I rarely prescribe weight-loss drugs for my patients.  They’re expensive.  They have side effects.  They’re not very effective.  And when you stop the drug, the fat returns.

Steve Parker, M.D.