A new generation of weight-loss medications that suppress patients’ appetites and make them feel full is facing reluctance among patients because of safety issues with past diet drugs.

The latest, Saxenda, from Novo Nordisk A/S, was approved by U.S. regulators late last year and hasn’t hit pharmacies yet. Other new appetite-suppressing prescription drugs on the market include Qsymia, Belviq and Contrave. Sales of the drugs have been slower than expected.

The new drugs are arriving after years of few drug options for treating obesity. They have known side effects and restrictions on their use. But some doctors say generally they appear safe and are cautiously prescribing them to help people lose weight. Under Food and Drug Administration approval of Saxenda, the prescribing label warns the drug caused thyroid tumors in rodent studies, and that patients with a personal or family history of medullary thyroid cancer shouldn’t take it. A spokeswoman for Novo Nordisk said it plans to start selling Saxenda by mid-year.

Concerns about cardiovascular-related side effects still linger years after previous weight-loss drugs made headlines. Wyeth, now owned by Pfizer Inc., withdrew one of the components of the so-called fen-phen drug combination in 1997 after it was linked to heart-valve damage in patients. And Abbott Laboratories withdrew Meridia from the market in 2010 because a study showed it increased risk of heart attack and stroke in patients.

“Healthcare practitioners are still a little wary of weight-loss medications because of this sort of checkered past,” says Thomas Wadden, director of the Center for Weight and Eating Disorders at the University of Pennsylvania. Another barrier to adoption is spotty insurance coverage: Some patients shell out $200 a month or more for the drugs, though companies have offered some discounts.

Click for more from The Wall Street Journal.