Engineers Design a Vibrating Pill for Weight Loss That Could Create a Feeling of Fullness

The capsule is the size of a multivitamin, and in an experiment with pigs, it appeared to reduce the animals’ appetites

Small pill with electronics inside
The capsule has a gelatinous coating that dissolves in stomach acid. Srinivasan et al. / MIT News

A vibrating pill that could trick your stomach into thinking it’s full could someday offer an obesity treatment that doesn’t rely on standard medications or surgery.

The device has not yet been tested in humans. But, in experiments with pigs, the capsule reduced the amount of food the animals ate by roughly 40 percent and triggered the hormones that signal satiety, according to a paper published in December in the journal Science Advances.

The pill is called the Vibrating Ingestible BioElectronic Stimulator, or VIBES for short. It contains a vibrating motor and a small battery made of silver oxide, all surrounded by a gelatinous membrane. Altogether, it’s about the size of a large multivitamin. When the pill is swallowed, stomach acids dissolve the membrane, which completes the electronic circuit and starts the motor.

The pill takes advantage of a physiological phenomenon discovered during past research: When a vibration is applied to a muscle, it creates the sensation that the muscle has been stretched farther than it actually has.

In the stomach, this stretching is called distension. When the stomach becomes distended, or full, the brain triggers hormones that signal it’s time to stop eating. Researchers wondered whether vibrations could artificially stretch the stomach and set off the hormone release patterns that typically occur after a meal.

After developing a prototype, they tested their invention on young Yorkshire pigs, which have a similar digestive system to humans.

Since pigs often chew pills before swallowing them, the researchers came up with a modified design for the experiments. They placed the pills inside pigs’ stomachs via a feeding tube, then activated them with an external battery for about 20 minutes before offering the animals food.

Over a two-week period, the animals with the vibrating pill in their stomachs ate 40 percent less than those without it. The pigs were juveniles, so they were still growing and did not lose any weight during the experiment, but those with the capsule gained weight more slowly compared to the control group, writes MIT Technology Review’s Cassandra Willyard. Researchers also tracked the animals’ hormone levels and found that they mirrored the release patterns usually seen after a meal.

The device seemed not to harm the animals, either. It did not appear to cause any perforations, obstructions, diarrhea, vomiting or inflammation. The pigs also behaved normally, though pigs that took the pills were less active after meals. In other tests, the capsules passed through the animals’ digestive systems within four to five days.

The capsule has a long way to go before it could become available to humans. At least in theory, it could provide an affordable, minimally invasive alternative to existing weight loss strategies such as gastric bypass surgery and GLP-1 agonist drugs like Ozempic.

“For a lot of populations, some of the more effective therapies for obesity are very costly,” says study co-author Shriya Srinivasan, a bioengineer at Harvard University who worked on the project while completing a PhD at MIT, in a statement. “At scale, our device could be manufactured at a pretty cost-effective price point. I’d love to see how this would transform care and therapy for people in global health settings who may not have access to some of the more sophisticated or expensive options that are available today.”

But many questions remain unanswered. For example, would people be willing to take such a pill before every meal? And what would it feel like to have a pill vibrating in your stomach?

“A pig can’t tell you how uncomfortable it is,” says Tom Hildebrandt, a clinical psychologist at the Icahn School of Medicine at Mount Sinai who was not involved in the new research, to Science’s Mitch Leslie.

In addition, it’s possible that the brain would eventually catch onto the illusion, which could make the pill less effective or cause it to stop working altogether.

“The brain might start to use other signals to decide how much to eat,” says Carlos Campos, a neuroscientist at the University of Washington who was not involved in the project, to MIT Technology Review. “We don’t know how long that trick is going to work.”

Moving forward, the researchers plan to explore how they could scale up the manufacturing of the pills. They want to experiment with additional features, such as the ability to control the device inside the stomach wirelessly, per the statement.

They also hope to study the pills in dogs, which have digestive systems that are even more similar to humans’. Future studies could allow the researchers to monitor the animals over time and see whether the device has any long-term effects on their weight.

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