On a November morning in 2022, James Messenger opened wide and swallowed a capsule like no other.
Messenger was no stranger to taking pills.
He'd first experimented with prescription opioids as a teenager in Morgantown, West Virginia, battled addiction on-and-off since, and known more than 70 people who had fatally overdosed. So, when asked to test a new "smart pill" that could detect an overdose in progress and call for help, he didn't hesitate to join the study.
"I've lost pretty much every good friend I've ever had to this," said Messenger. "This pill could save a lot of lives."
The new Vitals Monitoring capsule he tested is just one example in a growing effort to radically rethink what the humble pill is capable of.
As far back as 1965, scientists introduced the Heidelberg capsule, an electronic pill which measured acidity from within the gut. In 1994, the University of Buffalo coined the term "smart pill" with a device promising to ferry medicine to a precise spot in the intestine, "like the tiny ship in the film Fantastic Voyage." And in 2001, the US Food and Drug Administration (FDA) approved the first video capsule endoscope, a miniature-camera-toting pill that enabled noninvasive imaging of the small intestine.
Despite these milestones, the smart pill revolution has been slow to catch on due to cost, technological limitations, and some resistance among clinicians and patients.
But now, nearly, 300 iterations are in various stages of development, according to a 2022 analysis. Advances in materials, imaging, and artificial intelligence (AI) are helping address everything from sleep apnea to HIV/AIDS to gut disorders via real-time tracking and real-time help.
"These technologies could enable us to shift the paradigm from 'Let's wait until the patient comes to us and find out what happened' to 'Let's see how things are changing in real time, intervene now, and personalize that intervention,'" said Peter Chai, MD, an associate professor of emergency medicine and health technology researcher at Brigham and Women's Hospital in Boston, Massachusetts.
Tracking Vitals From the Inside Out
Already, overdose-reversal agents like naloxone are saving lives. But more than 60% of overdoses occur when no one is around to administer them.
"While we need to focus on treatment, we also need to come up with more acute ways to save individuals when treatment doesn't work or relapse occurs," said James Mahoney, PhD, director of addictions research at the Rockefeller Neuroscience Institute at West Virginia University (WVU), Morgantown, West Virginia.
Enter Celero Systems, a Massachusetts-based digital health company that has developed a vitamin-sized capsule packed with tiny sensors, microprocessors, and a radio antenna. It can measure breathing, heart rate, and core temperature — all from deep within the gut.
Respiratory distress is a hallmark early sign of an overdose. But it can be hard to monitor from a distance, especially in populations without access to a charged smartwatch.
Mahoney imagines a day when patients at risk could be given a weekly pill like Celero's. If their respiratory rate drops below a dangerous level, it could alert loved ones or, better yet, release an overdose-reversal drug.
"It's early days," stressed Mahoney, whose team has been conducting pilot tests of the pill. "But initial data look promising."
For one study, published in the journal Device in November 2023, the research team administered an overdose of fentanyl to anesthetized pigs with the pill in their stomachs. The capsule was able to detect respiratory depression within a minute and alert researchers via their laptop in time to step in.
When they gave the pill to 10 volunteers undergoing sleep studies at WVU, they found it could detect respiration rate with an accuracy of 93% compared with external monitoring devices — a feature that could also help diagnose sleep apnea or chronic obstructive pulmonary disease without expensive, intrusive tests.
Accuracy for heart rate was nearly 97%.
In another yet-to-be published trial, Mahoney tested the device with 10 volunteers in a residential treatment center to determine how well it could be tolerated.
Among the participants was Messenger, who said the thought of being tracked didn't bother him.
"It was simple — just like taking a multivitamin," said Messenger, now 34, sober, and working as a peer recovery support specialist at a hospital in his hometown. "It could be a great way to keep people alive long enough for them to get their head wrapped around the idea of treatment."
Boosting Medication Adherence
At Brigham and Women's Hospital, Chai is experimenting with a different smart pill — one he believes could help curb the ongoing HIV/AIDS epidemic.
Developed by Florida-based etectRx, the ID-Cap consists of a gelatin capsule embedded with a tiny radiofrequency transmitter, similar to the kind in retail antitheft devices. The capsule can be filled with a variety of medications. When swallowed, stomach acid dissolves the gel and activates the transmitter, which sends a signal to a receiver on a smartwatch, smartphone, or wall-mounted reader to confirm the medication was taken. If it isn't, the patient's smartphone or smart speaker might nudge them with a reminder or a family member might be notified.
In recent trials of men at a high risk for HIV, the system improved adherence to the once-daily prevention regimen pre-exposure prophylaxis (PrEP) by double digits.
"PrEP is almost 99% effective in preventing HIV, but you have to take it," said Chai, who led the trials. "That seems like such a simple thing, but anyone who is chronically on medication can tell you just how difficult it can be."
The pill is not the first designed to improve adherence. In 2017, the FDA approved the first digital ingestion tracking system, Abilify MyCite, for the treatment of schizophrenia and bipolar disorder. But its maker, Proteus Digital Health, filed for bankruptcy in 2020 after struggling to recruit patients willing to be tracked. (Some expressed privacy concerns. Others disliked the uncomfortable patch that received and forwarded the signal.)
More recent designs have been streamlined to ditch the patch, said etectRx Senior Vice President of operations Chris Carnes. And the cost of making a pill this kind of "smart" has come down to about a dollar.
So far, said Chai, in the patients he's worked with, perceived benefits generally outweigh privacy concerns.
Studies are now underway in patients with heart disease and tuberculosis, and the company hopes to move into the aging and memory care space where medication-adherence is a serious problem.
"For us, or any company in this space, to succeed, you have to have a strong business case," said Carnes. "If family members can keep their loved ones at home a little longer at an additional cost of $30 a month, that's a no-brainer."
Pillcams 2.0
Twenty-three years ago, the first video capsule endoscopy made it possible to image the small intestine via a tiny camera you swallow.
Such "pillcams" offered a more patient-friendly way to diagnose small bowel disorders, such as gastrointestinal bleeding and Crohn's disease. Rather than undergoing sedation or anesthesia, as required during tube-based endoscopy, patients can go about their day as the pill painlessly passes through their gastrointestinal (GI) tract, capturing and recording data and images.
But the pills have their downsides.
Because they move passively, driven by movement in the intestine, they can miss trouble spots. Their ability to image the esophagus, stomach, and colon has proven limited. And unlike other procedures, like colonoscopy, they can't intervene with therapy, like removing polyps.
The pillcam "had so much promise, to sort of revolutionize endoscopy, but it never really got the adoption that it seemed like it might," said Andrew Meltzer, MD, professor of emergency medicine at the GW School of Medicine and Health Sciences in Washington, DC.
That could soon change, he said, thanks to advances in locomotion and AI.
In a recent study of 40 patients, Meltzer tested a new magnetically controlled capsule endoscopy. Standing at a patient's side, he could use a joystick to steer the pill around the stomach, capturing images in real time.
The pilot study, published in June 2023, found that the pill clearly identified six key stomach landmarks accurately 95% of the time and didn't miss any lesions caught with traditional endoscopy. Notably, 80% of the patients preferred the pillcam over the tube.
"They are awake. They can go to work as soon as they leave. And it's easy for them to tolerate," Meltzer said.
More research is necessary, but Meltzer believes the technology could be particularly useful in the emergency department, allowing doctors to rule out high-risk bleeds in the stomach on the spot without admitting patients unnecessarily or making them return for a traditional scope.
"It has the potential to increase screening and provide more cost-effective care in emergencies," he said.
It could also be useful in the telemedicine space, allowing a doctor to "drive" the pill from afar to diagnose a distant patient.
Someday, AI could enable the capsule to drive itself, so a doctor could merely press a button and wait. Or it could be adapted to treat what it finds, like administering a drug or cauterizing a bleed.
"If we can come up with a Mars rover which can explore other planets, we should be able to have something that can explore the stomach remotely," Meltzer said.
Swallowing the Future
At the California Institute of Technology, researchers have developed a "location-aware" smart pill that uses magnetic fields to help pinpoint its location in the twists and turns of intestines. This could be useful for monitoring food in the GI tract to determine why things aren't moving.
Other researchers are using AI models to enhance the transmission of video from inside the body and reduce the time it takes to interpret images.
One group at the Massachusetts Institute of Technology has developed a vibrating weight loss capsule designed to stimulate receptors in the gut to signal the brain that the person is full.
Not everyone is a fan of the smart-pill revolution. Some critics have raised concerns about privacy. Others fear that doctors risk yielding too much power to technology. Even those who are excited about the pills' possibilities temper their optimism with caution.
None of these smart pills have gone mainstream yet in clinical practice, said Vivek Kaul, MD, professor of medicine at the University of Rochester Medical Center, Rochester, New York, and secretary general of the World Gastroenterology Organization.
Clinical validation, accessibility, and insurance coverage "will be critical in shaping their role," he said. "But overall, it would be fair to state that this technology has come of age and the future is bright."