Article edited for scientific accuracy by Illuminate Labs Blog Editor Taylor Graber MD
Plenity is an FDA-approved weight management supplement for adults who are overweight and obese. The idea of a pill that can help you lose weight sounds too good to be true for many Americans. After all, many are so desperate that they’re using dicyclomine for weight loss (off label), which we strongly recommend against.
In this article we’ll review the formulation behind the Plenity weight loss prescription pill, along with potential side effects and natural alternatives, and explain why we think it’s a waste of money.
Formulation Review | Inactive Ingredients
It’s very hard to find the full ingredients list for Plenity which is a red flag in our opinion. Why not publish it transparently?
Their site references two active ingredients: cellulose and citric acid. But many pharmaceutical products (and even food products like Premier Protein), have inactive ingredients which may be harmful.
Plenity’s FAQ section states that people allergic to sodium stearyl fumarate, gelatin or titanium dioxide should not take the product, so we can assume these are the three inactive ingredients. Again it’s quite strange in our opinion that they’re arguably hiding this information in an obscure section of their site.
Europe, which has much more stringent consumer health regulations than the U.S., recently disallowed use of titanium dioxide as a food additive due to concerns over genotoxicity.
Formulation Review | Active Ingredients
Cellulose is an insoluble plant fiber contained in nearly every plant food, such as apples, oranges, kale and bananas. This is not a rare and exotic ingredient that’s hard to come by.
Citric acid is another common food compound, found in citrus fruits among other foods.
Plenity claims that these two ingredients combine and react with water in the stomach to create a sense of fullness which reduces overeating. We have no reason to disbelieve this since cellulose is a basic fiber obtainable from many other foods and fiber is known for increasing satiation.
Clinical Trial Review
Plenity funded a clinical trial, comparing use of their product with placebo. The results showed that patients taking Plenity had superior weight loss outcomes (by a small but statistically significant amount) compared with placebo.
This study was very poorly designed in our opinion. They accepted patients into the study who had fasting blood glucose levels between 90 and 145 mg/dl. Pre-diabetes levels are 100-125 mg/dl, and anything over 125 mg/dl is full blown diabetes according to the CDC.
Just because a treatment works on diabetics and pre-diabetics doesn’t mean it will translate into results for healthy adults, so it’s strange to us that Plenity doesn’t highlight this on their site.
Additionally, the study doesn’t specify what the placebo material was, but if it wasn’t a fiber then it would be very disingenuous, because we know dietary fiber intake alone promotes weight loss based on medical research.
So if the placebo were rice flour, it would be unimpressive that Plenity barely outperformed it in regards to weight loss, while if it were a fiber product it would be more impressive. Because the study doesn’t specify exactly what the placebo material is, we can probably assume it’s not a fiber and the study was intentionally designed in a manner to achieve favorable results.
Potential Side Effects
The study found no significant difference in side effects between Plenity users and placebo, which is good.
On their site, they list fullness, bloating, abdominal pain and flatulence as potential side effects. These are very minor side effects in regards to pharmaceutical drugs, and are unsurprising given that regular fiber intake can cause the exact same side effects if consumed in excess.
As stated in the clinical trial review, we already know that whole food fiber intake is associated with superior weight management outcomes.
Fiber makes you feel full, and leads you to consume less calories overall. It’s much easier to eat 2,000 calories of burgers and fries in one sitting than it is to consume 2,000 calories of rice and beans because the first meal has much less fiber than the second.
In our opinion, there’s no point in paying the significant cost of Plenity ($98 per month) when you could achieve similar or superior outcomes by just eating more dietary fiber at a fraction of the cost. You’d also get all of the other nutrients in the whole food fiber and avoid inactive filler ingredients like titanium dioxide.
We evolved over millennia to consume high fiber diets so we know for certain it’s a safe dietary modification. We didn’t evolve for millennia taking “superabsorbent hydrogels” so we can’t be as certain of the long-term safety.
Plenity is a total waste of money in our opinion. It’s not that the pills are necessarily harmful, it’s just that, like with frozen fruits and vegetable supplement Balance of Nature, you can get the same or better results at a fraction of the cost with no potential long term risk.
Put down the Plenity and have a dinner with beans and salad and you’ll probably end up feeling a lot better long term.