My dad, Randy, a 72-year-old retired sales manager, started to gain weight after grad school, and it didn’t let up until he was middle-aged. He’s now living with high blood pressure and high cholesterol.
His cardiologist has told him, “You know, if you lost 15 pounds, you could get off your blood pressure medicine.”
When my dad started seeing commercials for Wegovy, he was curious but skeptical. Injections seemed invasive, and he wondered how the drug would interact with the other medications he was taking. But after trying many diets with no lasting success, he began wondering if taking a medication for weight loss was the right thing to do for his health.
As he wondered, the rest of the world marveled at the seeming medical miracle of achievable weight loss with a weekly shot. Semaglutide and tirzepatide (sold under the brand names Wegovy and Zepbound) mimic hormones called GLP-1 and GIP, which act in the brain to reduce hunger and in the gut to delay emptying. These effects combine to cause weight loss, and can result in up to 25% body weight loss in as little as 18 months.
Many insurers now cover their use for weight loss. But Medicare, the government-backed insurance that covers most adults 65 years or age and older, won’t pay for weight loss medications. The House of Representatives is actively considering the Treat and Reduce Obesity Act, which would cover these medications under Medicare. But for now, Wegovy and Zepbound cost more than $1,000 per month, meaning most of the 10 million older adults like my dad won’t be able to access this potentially life-changing treatment.
Maybe Medicare is right to hold off.
In the excitement around the drugs, an essential question has not been answered: Are these medicines right for older people? As a primary care physician and researcher who studies obesity in older adults, I’m not sure they are. While I want my older patients to have access to treatments for obesity, there are not adequate data to support the use of these new medicines in older adults.
The studies that were used to gain FDA approval for these drugs included few adults over 64 years of age. In the semaglutide trials, for example, only 11% of the participants enrolled were 65 or older. With so few older participants, it’s impossible to know if these medications are right for all older adults with obesity, or just the ones who happened to take part in the trials. In other words, there might not have been enough people like my dad, a 72-year-old Asian American man with high blood pressure, high cholesterol, and prediabetes in the trial for me to feel comfortable he can take this medication safely — and that the benefits will outweigh the side effects.
Additionally, older adults have different goals of treatment than younger adults, making it unwise to assume that if a medication works for younger adults, it’s good enough for older ones, too. An important reason to treat obesity is to prevent secondary conditions like diabetes or cardiovascular disease. An older adult may already have acquired these secondary illnesses or will have far less lifetime to benefit from the prevention provided by weight loss. In addition, an older adult’s goals might be more oriented around quality of life, like living with less pain or being able to walk without a walker. There’s no information on whether Wegovy or Zepbound will help with that.
With so few older adults in the clinical trials testing these medicines, not enough is known about the side effects in older adults. I’m particularly concerned about the loss of muscle mass. In the trial of tirzepatide for weight loss, participants who had their body composition measured lost on average 11% of their muscle mass. Older adults with obesity are more likely to have impaired mobility, which could be made worse by loss of muscle. While no one has investigated if muscle mass loss from Wegovy or Zepbound will worsen physical function among older adults with obesity, I’ve had patients taking these medications say they felt weaker after losing large amounts of weight. Dieting can also be accompanied by loss of muscle mass, but the weight loss — and muscle loss — caused by these medications is unprecedented.
To be sure, older adults living with obesity need effective and safe treatments. Over 40% of older adults have obesity. Preventing the negative results of it — cardiovascular disease, kidney disease, impaired mobility, and more — is important in the geriatric population. But without the knowledge of side effects and benefits, I can’t assure my patients, or my dad, they will be safe taking these medications. Clinicians wouldn’t use a medication on children that wasn’t tested in children, and we should take the same approach to older adults.
While researchers like me work to understand the effect of these medications on older adults, Medicare should wait to cover them for people with obesity until there’s enough data to support their use. I know that is frustrating for patients and family members awaiting a cure for obesity — I hear it from them all the time — but it is the safest option.
Older people who are considering taking these medications should ask their doctors some important questions: Could they interact with the medications I’m taking? How long would I need to be on the medication? Are there side effects I should be worried about? Similarly, health care providers should ask themselves some questions before prescribing these drugs to their older patients: Does my patient have signs of impaired mobility, and could they be worsened by loss of muscle mass? Will losing weight help my patient achieve their treatment goals? Were there participants in the clinical trials that represented my patient’s unique profile?
I want a good and safe treatment for obesity for my patients and my dad. I want him to live a full and long life, free from chronic illnesses and disability. But I also want to know that whatever medication he takes is safe and beneficial for him in the long run. From the little we know about Wegovy and Zepbound, I’d rather he try cutting back on late night snacking before taking repeat injections.
Alissa S. Chen, M.D., is a primary care doctor, obesity medicine specialist, and research fellow in the National Clinician Scholars Program and Geriatric Clinical Epidemiology and Aging Related Research Program at Yale University.