Weight Management

Do You Need to See an Endocrinologist Before Starting a Weight Loss Drug?

Originally published July 8, 2024

Last updated July 15, 2024

Reading Time: 4 minutes

A doctor looks at a paper on a table in front of a patient holding a bottle of pills.

Losing weight can be difficult. Seeing a specialist can help determine if weight loss drugs are right for you.

It can be difficult to lose weight once you gain extra pounds. Most people first turn to the basics, increasing physical activity and cutting back on how much they eat. However, no matter how hard some people try, they might not be able to lose weight with diet and exercise alone. You might be wondering if you should try a weight loss drug to lose stubborn pounds. Before you try to get a prescription for a drug like Wegovy or Zepbound, you might want to speak to a specialist first, says Alyssa Dominguez, MD, an endocrinologist at Keck Medicine of USC. 

“Many general practitioners don’t feel comfortable prescribing obesity medication,” she says. She recommends people see an endocrinologist or a physician specializing in obesity who can determine if there is an underlying condition that’s contributing to your difficulties losing weight.  

Endocrinologists treat a variety of conditions including diabetes, thyroid disorders, pituitary disorders, osteoporosis, polycystic ovarian syndrome and obesity, says Dominguez.

When should I see an endocrinologist?

There’s a huge variety of reasons a general practitioner might send one of their patients to see an endocrinologist, says Dominguez. “I have some patients who come to see me just because they have a question about their hormones,” she says. “For example, ‘I’m feeling a lot of stress,’ or ‘I can’t lose weight.’”

Many people will turn to traditional methods for weight loss when they first try to lose weight, such as seeing a nutritionist, getting on an exercise program or using a weight loss program such as Noom, Jenny Craig or WW.

“A lot of these medications that we’re using now are relatively new, so I’m certainly seeing people who have struggled for decades who are interested in some of these more effective weight loss medications that are on the market now,” she says.

Endocrinologists see people of all ages, but Dominguez says she mostly sees younger adults who are curious about weight loss drugs. She attributes this to the fact that younger patients might be more aware of new treatments that are available and willing to seek them out, as well as the fact that there is a stigma towards people who are obese, especially for younger people.

What tests will an endocrinologist do to see why I can’t lose weight?

“One of the initial evaluations that we do is to see if there is an underlying endocrine pathology that is leading to that weight gain,” says Dominguez. “If we don’t find anything underlying, oftentimes at that point we will discuss strategies for weight loss, which of course tend to include nutritional counseling, exercise and may also include weight loss medications or weight loss procedures.”

What underlying hormone conditions might prevent me from losing weight?

“Certainly hypothyroidism, or having too low levels of thyroid hormone, can make weight loss more challenging and can predispose to a little bit of weight gain,” Dominguez says. Your endocrinologist will likely be looking at labs to determine if you have any weight-related comorbidities such as diabetes, hypertension or hyperlipidemia.

A lot of people also come and ask about cortisol excess, Dominguez says. “There is a lot of misinformation out there about cortisol excess,” she says. “What we are looking for as endocrinologists is pathologic cortisol excess that would typically be attributed to a tumor either in the adrenal gland or the pituitary gland.”

What hormone conditions might prevent me from taking weight loss drugs?

Medications such as Wegovy or Zepbound should not be used in people with a personal or family history of medullary thyroid cancer. Additionally, if someone has underlying gastrointestinal slowing issues, like chronic constipation or slow stomach emptying, Wegovy or Zepbound would likely worsen those issues.

Other medications have other contraindications based on their underlying mechanism of action. For example, Qsymia should not be used in people who have uncontrolled high blood pressure or thyroid levels that are too high, says Dominguez.

What weight loss drug works the best?

Dominguez tends to start people on whichever medication might be most effective for a patient, rather than prescribing a less effective drug first. However, Dominguez does recommend most of her patients see a nutritionist first to make sure they’re getting adequate nutrition.

“Each medication has different side effects, so when talking to different patients, I discuss various side effects and what will work best for them,” Dominguez says.

Here are some common weight loss drugs and their side effects:

  • Zepbound and Wegovy can both cause decreased appetite, slowed stomach emptying, nausea, vomiting, abdominal pain, constipation or diarrhea.
  • Qsymia, since it’s a stimulant, can cause feelings of anxiety or heart racing.
  • Older medicines like Alli, with the generic name orlistat, can cause oily stools.

“Usually, I gravitate toward prescribing the most effective ones, but if there are barriers such as an unacceptable side effect profile or too high of a cost, then I’ll go to maybe one of the less effective drugs,” Dominguez says.

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Mollie Barnes
Mollie Barnes is a digital writer and editor at Keck Medicine of USC.