As Plenity Gains Popularity for Weight Loss, Some Question its Efficacy

Gelesis' weight loss device, Plenity, has been gaining popularity since the U.S. Food and Drug Administration granted approval for its commercialization. The regimen is prescribed not only for its efficacy, which isn't statistically groundbreaking, but for its simplicity. 

According to CBS News, patients who are prescribed Plenity can expect to feel satiated after eating a smaller plate. This is attributed to the device's mechanism, which uses a capsule delivery system to encase small grains of cellulose hydrogel. 

Cellulose comes from plant cell walls and can be found in foods such as ice cream or broth. Herbivores can digest cellulose, but humans cannot. Instead, cellulose exits the human body as waste. Plenity follows this path, filling the stomach as much as 25% as the grains swell before being safely excreted. 

Coupled with this mechanism, patients are instructed to take three capsules twice daily before eating a meal. Most insurance companies won't cover Plenity. This might be due to the novelty, underwhelming efficacy or even because it can be prescribed to patients with a lower BMI than other weight loss prescriptions. 

In a clinical setting that lasted six months, 59% of the participants lost 5% of their body weight or more. The average weight loss per participant was 6.4%. This stands in comparison with the placebo group, in which participants lost an average of 4.4% of their body weight.

All participants, regardless of being placed experimental or placebo group, were required to eat 300 calories less than the daily caloric intake needed to maintain their current weight. While this device could have been explored as a supplement, Gelesis felt that clinical trials were critical to showing the science and establishing trust with patients and prescribers.

In March, Gelesis released preliminary results from its nationwide launch. Prescriptions reportedly increased as quickly as the company was able to manufacture them.  

"We are offering clinically proven healthcare with the convenience you expect from e-commerce. You can seek out a Plenity prescription at any time, from anywhere, at an affordable cost," David Pass, Pharm.D., chief operating and commercial officer of Gelesis, said in a statement at the time. "We saw in our clinical studies that 6 out of 10 of people were responders and consistent with that, 60% of our members have ordered multiple monthly kits within the limited time Plenity has been available. We are very excited by what we are hearing from members about their real-world experience."

Pass mentioned that Gelesis hopes to enable physicians to prescribe Plenity as quickly and efficiently as possible. To do this, the company has partnered with the telehealth platform Ro. In 2021, Ro placed a $40 million pre-order of Plenity to ensure telehealth patients receive the product. This year, Ro requested an additional pre-order of $15 million in products, bringing the total valuation to $55 million.

The weight loss market is saturated with prescriptions that help patients achieve a more significant weight drop, but those often come with hefty price tags and worrisome side effects. Plenity can be purchased out of pocket for under $100 per month when it isn't covered by insurance. Compared to other treatments that reach over $1000, patients with tighter pockets are more likely to choose the inexpensive option.