Dr. Joel Ross Explains Why Older Adults Are Missing From Drug Trials

Walk into almost any geriatric practice, and the waiting room usually tells a story that clinical trial data often does not. The patients are in their 70s, 80s, and 90s. Many take five or more medications, manage several chronic conditions, and arrive with a spouse or adult child who typically handles the driving.

These patients are likely to be prescribed newly approved drugs, yet people like them are often underrepresented in the studies that got those drugs approved.

Dr. Joel Ross has spent more than 35 years working inside that care gap. A New Jersey geriatrician and clinical researcher, he has served as a principal investigator or co-investigator on 140 clinical trials, with experience ranging from trial design and execution to patient enrollment and retention. That experience gives him a clear view of why older adults so often go missing from clinical trial data and what it would take to bring them into the fold.

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The People Taking the Drugs Are Not the People Testing Them

The United States is aging quickly. Census Bureau estimates released in 2025 put the population age 65 and older at 61.2 million. Those estimates also showed that older adults outnumbered children in 11 states and nearly half of all U.S. counties. Older Americans account for a large share of the country's medication use, too. According to the Centers for Disease Control and Prevention, about one-third of adults in their 60s and 70s used five or more prescription drugs over 30 days.

Unfortunately, clinical trial enrollment hasn't kept pace with that data. An FDA analysis presented at the American Society of Clinical Oncology's 2017 annual meeting found that adults 65 and older made up about 40 percent of cancer trial participants, even though they represented more than 60 percent of people with cancer. The gap only widened with age. Patients 75 and older accounted for 37 percent of people with lung cancer but only 9 percent of lung cancer trial participants. For colon cancer, the figures were 33 percent and 8 percent. For breast cancer, they were 19 percent and 4 percent.

The problem isn't limited to oncology. A 2026 study in the Journal of Clinical Epidemiology reviewed 207 COVID-19 vaccine trials and found that only 9 percent of the more than 700,000 participants were 65 or older. The study also noted that this age group made up 18 percent of the U.S. population and accounted for 76 percent of COVID-19 deaths.

Exclusion Criteria Do Most of the Work

Explicit upper age limits get the attention, but they're only part of the story. In the COVID-19 vaccine analysis, just 35 percent of studies set a maximum age. Far more common were exclusions for conditions such as hypertension, diabetes, and cancer, all of which are more prevalent in older adults. Trials that used those exclusions tended to enroll younger participants, even without an upper age limit.

The same pattern shows up in Alzheimer's research, where older adults make up much of the patient population. In a 2023 analysis published in Neurology, Mayo Clinic researchers applied the lecanemab trial's criteria to 237 people with mild cognitive impairment or mild dementia and evidence of amyloid buildup, drawn from a population-based study. About 47 percent met the inclusion criteria. Once exclusions such as a history of stroke, cardiovascular disease, cancer, and certain brain imaging findings were applied, only 8 percent remained eligible.

For Dr. Joel Ross, who completed his geriatric medicine fellowship at Mount Sinai Medical Center under Dr. Robert N. Butler, the first director of the National Institute on Aging, that result reflects something geriatricians see every day. Older patients rarely arrive with a single, isolated diagnosis. Kidney function may decline. Heart rhythms can change. Medication lists grow. A protocol that screens out each of those factors can end up studying a healthier, younger group than the one that will eventually use the drug.

Why Sponsors Keep Designing Narrow Trials

Trial sponsors have understandable reasons for choosing narrow study populations. A study that enrolls participants with fewer health problems can make the results easier to interpret. There may be fewer adverse events unrelated to the drug and fewer participants who drop out. A drug's effects can be easier to detect, and timelines can be easier to predict. For a company investing heavily in a single compound, those advantages are hard to ignore.

The trade-off becomes clear after approval, when a physician has to decide how a drug will behave in an 82-year-old with heart failure, reduced kidney function, and a long medication list. Dosing, drug interactions, and side effect rates observed in healthier participants may not apply in the same way. Clinicians are left making judgments with limited evidence, and patients face the uncertainty.

Ross has approached this problem from both sides of the research process. Through the Memory Enhancement Center of America, which he founded in 2000, his team took part in clinical trials for oral and transdermal Alzheimer's medications that are now approved. As founder and CEO of J&D Pharmaceuticals, he also works on the development side, advancing investigational compounds that the FDA hasn't approved. Across both roles, his work has focused on whether research produces better health outcomes for older adults in everyday clinical care.

The Practical Barriers Nobody Writes Into the Protocol

Even when older adults qualify, the demands of participating can shut them out. Trials often require frequent site visits with long appointments for infusions, imaging, blood draws, and cognitive testing. For a patient who no longer drives, each visit may depend on a family member taking time off work. Mobility problems, hearing or vision loss, and unfamiliarity with electronic diaries or app-based check-ins can make participation even harder.

Recruitment has its own blind spots. Many trials recruit through academic medical centers, while many older adults receive their care from community physicians who may not know which studies are enrolling. Investigators may also hesitate to approach frail patients, assuming they won't tolerate the protocol or will leave early.

These are the kinds of problems a principal investigator can see long before they appear in a published paper. Dr. Joel Ross wrote a primer for investigators titled "PI: Principal Investigator or Practically Invisible?" and served as a trustee of the Association of Clinical Research Professionals. The title points to the importance of staying involved in a study's day-to-day work. Investigators who stay engaged are better placed to answer questions, spot problems, and help participants stay involved.

Policy Is Starting to Push in the Right Direction

Regulators have recognized the gap for years. The National Institutes of Health's Inclusion Across the Lifespan policy, which took effect in January 2019, requires researchers conducting NIH-funded human subjects research to include people of all ages unless there's a scientific or ethical reason not to, and to justify age-based exclusions.

In December 2025, the FDA finalized guidance titled Enhancing Participation in Clinical Trials: Eligibility Criteria, Enrollment Practices, and Trial Designs. The guidance notes that gaps remain among older adults and patients with multiple health conditions. It cautions sponsors against automatically excluding these patients without clinical justification and encourages approaches such as fewer study visits, remote assessments, and electronic consent.

Guidance alone doesn't enroll patients, though. Much of the work happens at the site level, where coordinators and investigators consider how flexible a visit schedule can be, whether transportation help is available, and whether an exclusion is necessary for patient safety.

What More Inclusive Trials Would Look Like

Closing the gap starts with eligibility criteria based on the drug's risks and how it works. For example, researchers can consider whether the drug's safety profile justifies a kidney function cutoff and how the body processes it. Patients with stable, well-managed chronic conditions may be able to participate with appropriate monitoring.

Participation also has to be easier. Home visits, telehealth check-ins, flexible visit windows, and transportation support can lower the burden on patients and caregivers. Partnering with community practices and geriatric clinics brings studies to where older adults already receive care.

Trials should also measure what matters to older patients and report it clearly. Outcomes such as independence, fall risk, cognitive function, and quality of life belong alongside standard measures of how well a treatment works. Reporting results separately for participants 75 and older can also reveal differences that a single 65-plus category might hide.

This emphasis on the whole patient runs through Ross's career. He became the first geriatrician to practice in New Jersey. He built the state's first geriatric fellowship program, spending years training physicians in geriatric care who went on to practice across the country. For Dr. Joel Ross, the lesson from decades at the bedside and in the research clinic is simple: if a drug will be used mostly by older adults, older adults belong in the trial.

About Dr. Joel Ross

Dr. Joel Ross is a New Jersey geriatrician, clinical researcher, educator, and author with nearly four decades in medicine. He earned his medical degree from Downstate Medical Center and completed his geriatric medicine fellowship at Mount Sinai Medical Center. He served as the first Medical Director of the Anna Alexander Greenwall Geriatric Program at Monmouth Medical Center, where he was named Teacher of the Year. He later directed the geriatrics section of the Department of Internal Medicine at 

Jersey Shore Medical Center

His clinical work has centered on diagnosing and treating conditions associated with aging, including cognitive disorders, with an approach built on careful evaluation, evidence-based treatment, and respect for patient dignity. He founded and leads J&D Pharmaceuticals LLC in Monmouth, New Jersey, and volunteers at Parker Health Center in Red Bank, where he provides free care to older patients.

This is a guest blog entry.

When Are Mounjaro Sulfur Burps Normal and When Are They a Warning Sign?

Sulfur burps on Mounjaro catch almost everyone off guard. You start a medication prescribed to control blood sugar or support weight loss, and within days you're dealing with a smell that belongs in a biology lab - not at the dinner table. It's uncomfortable, occasionally alarming, and confusing enough that plenty of people wonder whether to stop their dose, call their doctor, or just wait it out. The honest answer depends on what's going on alongside the burps. Mounjaro sulfur burps are a documented side effect, and most of the time they're not dangerous. But certain symptom combinations - paired with those rotten-egg belches, genuinely need medical attention. Knowing the line between "my body's adjusting" and "this is a red flag" is the most useful thing you can take from this article.

Why Mounjaro Causes Sulfur Burps in the First Place

Tirzepatide - the active ingredient in Mounjaro - slows gastric emptying significantly. That's part of how it works. Food lingers in the stomach longer, and that delayed transit gives gut bacteria more time to ferment sulfur-containing compounds in what you eat. The byproduct is hydrogen sulfide gas, which is responsible for the characteristic rotten-egg smell. If you've been researching Mounjaro sulphur burps and wondering why nearly every account describes the same odor, that's your answer - it's the same gas no matter what you ate. High-sulfur foods speed the process up, but even a modest meal can set off burps during the early weeks. The mechanism isn't a malfunction. Your digestive system is simply running slower, and sulfur fermentation is a predictable consequence of that slowdown - context that changes how you interpret what your body is doing.

How GLP-1 Receptor Agonists Slow Digestion

Mounjaro is a dual GIP and GLP-1 receptor agonist, and one of its effects is a gastroparesis-like slowing of the stomach. Gastric emptying that normally takes two to four hours can stretch to six or longer in some patients. In a 2023 review published in Gastroenterology, researchers at the University of Michigan documented gastric retention in GLP-1 users, noting the effect is most pronounced during the first several weeks of treatment and after each dose increase. That's relevant to sulfur burps because the longer food sits in the stomach, the more fermentation takes place. Proteins from eggs, meat, legumes, and cruciferous vegetables are especially sulfur-rich, and bacterial breakdown of those proteins is what generates hydrogen sulfide. The burps signal that the drug is active, not that something's gone wrong. Most patients notice the worst episodes within 24 to 48 hours of each weekly injection, which lines up exactly with peak drug concentration in the bloodstream.

What Normal Sulfur Burps Look and Feel Like

Normal sulfur burps on Mounjaro follow a recognizable pattern, and once you know what to expect, they're much easier to distinguish from something more serious. They tend to appear within the first day or two after your injection. They smell strongly of sulfur or rotten eggs. They may come with mild nausea, some bloating, or a feeling of fullness that won't budge, all of which are also standard GI side effects of tirzepatide. The important thing here is mild. You should still be able to drink fluids, eat small amounts, and function during your day, even if you feel off. The burps typically ease up as your dose cycle winds down, then return when you inject again. You might also notice them settle down over several months as your body adjusts to the drug. If that pattern describes what you're going through, you're most likely in normal-adjustment territory. Discomfort is real, but it's not the same as danger.

When Sulfur Burps Cross Into Warning-Sign Territory

Not every case of Mounjaro-related sulfur burps stays in "normal adjustment" territory. Some symptom combinations point to complications that need a doctor's input, and spotting them early matters. The GI effects of tirzepatide can occasionally tip into pancreatitis, severe gastroparesis, or a worsening of an underlying condition. None of those are common, but they do happen, and they share early symptoms with garden-variety indigestion. The difference usually shows up in severity, duration, and what else your body is doing at the same time. Sulfur burps that arrive alongside localized pain, high fever, or persistent vomiting aren't typical drug adjustment, they're a signal that something else is happening and your GI tract needs a closer look.

Symptoms That Signal a Bigger Problem

Certain symptoms paired with sulfur burps should prompt a call to your doctor the same day - or a trip to urgent care if they're severe. Watch for these:

•  Severe or persistent abdominal pain - especially pain that radiates to your back or upper left abdomen, which can indicate pancreatitis
• Vomiting that doesn't stop - unable to keep down any liquids for more than a few hours
• Fever above 101°F - not typical for a GI side effect and suggests infection or inflammation
• Dark or tarry stools - a sign of bleeding somewhere in the GI tract
• Jaundice - yellowing of the skin or eyes, which points to liver or gallbladder involvement
• Severe dehydration - dry mouth, no urination, dizziness when standing

Mounjaro carries an FDA-mandated warning for pancreatitis, and its early symptoms overlap significantly with bad indigestion. The FDA's 2023 prescribing information for tirzepatide explicitly advises discontinuing the drug if pancreatitis is suspected. Don't wait to see if it improves on its own.

How Long Is Too Long Before You Call Your Doctor

Mild sulfur burps that stay mild, no fever, no severe pain, no vomiting you can't manage, can reasonably be monitored at home for a week or two, especially in the first few months on Mounjaro. But duration matters. Burps that persist past two weeks without any improvement, or that get worse rather than better after a dose adjustment, deserve a conversation with your prescribing provider. Your doctor may want to rule out small intestinal bacterial overgrowth (SIBO), which can develop or worsen in people with slowed motility, and which produces exactly the same symptom profile as normal Mounjaro GI effects. SIBO is treatable, but it won't resolve on its own. If your symptoms follow the weekly injection cycle closely and ease up by day five or six, you're likely looking at normal drug pharmacokinetics. If they run continuously without any pattern, get that checked.

Practical Ways to Reduce Sulfur Burps on Mounjaro

You don't have to simply endure the sulfur burps and wait for your body to adjust, though adjustment does happen for most people over time. Several diet and timing strategies make a real difference, and they don't require any special products or supplements.

Diet and Timing Adjustments That Actually Help 

The single most effective change is cutting back on high-sulfur foods in the 24 to 48 hours after your injection, since that's your peak-symptom window. High-sulfur foods include eggs, red meat, garlic, onions, cruciferous vegetables (broccoli, cauliflower, cabbage), and beer or wine. You don't need to cut them permanently - just dial them back around injection day. Eating smaller, more frequent meals during that window also reduces the fermentation load, since less food sits in a slowed stomach at any one time. Stay upright for at least an hour after eating so gas can move through rather than pool at the gastric level. Some patients find peppermint tea or simethicone eases the bloating that tends to accompany the burps, though neither targets the root cause. Sipping water consistently throughout the day - rather than drinking large amounts at once, also supports motility without overwhelming a stomach that's already sluggish.

Conclusion

Mounjaro sulfur burps are among the more unpleasant side effects of tirzepatide, but for most patients they're a sign the drug is working rather than a sign of harm. What matters is what comes with them. Burps arriving a day or two after injection, feeling mild to moderate, and easing on their own fit the normal adjustment pattern. But sulfur burps paired with severe abdominal pain, persistent vomiting, fever, or signs of dehydration need prompt medical attention. Diet adjustments during your peak-symptom window can meaningfully cut the frequency and intensity of episodes. And if the burps run continuously without any weekly pattern - or if they're getting worse rather than better after two months on the medication - bring that up with your prescribing provider. A conversation early is almost always better than waiting to see how bad it gets.

This is a gust blog entry.