Metamucil is a fiber brand owned by Procter & Gamble, and is arguably the most popular fiber supplement in the US. The brand's website claims that their products can "support your digestive health" and cause users to "feel lighter & more energetic."
But does Metamucil contain high levels of lead? Does it provide an effective fiber dose for gut health? Does it contain unhealthy additives? And is Metamucil better or worse than competitors like Benefiber and Miralax?
In this article we’ll answer all of these questions and more, as we highlight a lawsuit over the alleged lead levels in one Metamucil product.
We'll also analyze the ingredients in Metamucil to give our take on whether or not it's healthy, discuss the risk of side effects, and compare Metamucil to other popular digestive health supplements to pick our winners (and losers).
Key takeaways:
- Metamucil sued over lead content
- Contains inactive ingredients we consider to be unhealthy
- We do not currently recommend Metamucil
Is Metamucil Contaminated?
In 2023, Metamucil was sued over allegations of high lead levels in at least one of their products.
According to a news report on the lawsuit, lead levels up to 2,724% of the legally allowed concentration were found.
While some food products and supplements contain a small amount of lead due to environmental contamination, according to the Centers for Disease Control (CDC), the lead level alleged in the lawsuit is concerning in our opinion.
A medical review documented that lead is a highly poisonous metal that negatively affects all organ systems, and minimizing its ingestion as much as possible seems prudent.
We recommend that consumers speak with their doctor about whether or not Metamucil is safe to consume in light of this information.
Ingredient Analysis
The ingredients in Metamucil's fiber powder are shown below:
Psyllium husk is a type of fiber, and medical research shows that increasing fiber intake can have a range of health benefits such as decreased blood pressure, improved gut function and even weight loss.
Metamucil has updated this formulation since we initially published this article.
Sucrose is a type of sugar, and is now used instead of the artificial sweetener aspartame.
Two tablespoons of Metamucil Fiber Powder provides 16 g of added sugar.
Added sugar consumption in excess is associated with an increased risk of cardiovascular disease according to a 2014 population study.
This product also contains a number of inactive ingredients that may be questionable from a health perspective.
Citric acid is clinically shown to cause whole-body inflammation in some individuals, as we documented in our Colon Broom vs Metamucil article.
Natural and artificial orange flavor may also be unhealthy.
A medical study published in the Food Technology & Biotechnology journal found synthetic orange flavoring to cause acute toxicity in animal studies.
Yellow 6 is an artificial food dye which has been found in medical research to be contaminated in some cases with carcinogens (cancer-causing chemicals). We recommend avoiding all artificial food dyes.
Overall, we consider two tablespoons of Metamucil to provide an adequate fiber dose for a fiber supplement.
We do not currently recommend this product and do not consider it to be healthy due to the added sugar and inactive ingredients discussed above.
Does Metamucil Cause Side Effects?
We can't find any clinical trials on Metamucil, which makes it more challenging to determine whether or not the supplement is likely to cause side effects.
However, we can make an educated guess based on its ingredients.
Any fiber supplement (or high-fiber food) may cause digestive discomfort in individuals used to a low-fiber diet, and may cause symptoms like gas and bloating.
This is why it's important to gradually increase fiber intake over the course of days and weeks.
The specific type of fiber in Metamucil called psyllium husk fiber may have a greater risk of side effects than other types of fiber, according to a YouTube video published by an adjunct professor at the University of Illinois, shown below.
The video has over 1 million views at the time of updating this article.
We want to be clear that we do not consider there to be any risk of serious side effects when using Metamucil at the directed dose.
This video is presented for educational purposes about the risk of high doses of the type of fiber in Metamucil:
Does Metamucil Cause Weight Loss?
Metamucil may cause weight loss in overweight and obese individuals, but that's due to the fiber content and not anything unique to Metamucil's formulation.
A meta-study found that fiber intake is associated with weight loss. The study authors found that an additional 14 g per day of fiber intake was associated with a 10% decrease in calories consumed from diet.
Fiber is low-calorie plant material that takes up space in the stomach, so it causes individuals to feel full faster and can therefore be a natural, effective weight loss aid.
We consider any fiber supplement to have an equivalent chance of causing weight loss in overweight individuals. What matters in regard to weight loss is the fiber dose.
Higher daily intakes of fiber are associated with greater weight loss according to the above-linked review, but may also be associated with greater risk of side effects.
Which Metamucil Product is Healthiest?
Metamucil sells a wide variety of fiber supplements, including powders, gummies and foods.
Here's our take on the relative healthiness of some of the brand's most popular products:
Real Sugar Fiber Powder
We reviewed this product in the Ingredient Analysis section above, and noted that it contains a relatively high dose of added sugar, and several questionable inactive ingredients.
Our verdict: Unhealthy
Premium Blend Fiber Powder
Naturally colored with paprika and turmeric rather than artificial colorants.
Sweetened with stevia instead of refined sugar, and contains natural flavor but not artificial flavor.
Our verdict: Relatively healthy
Sugar-Free Fiber Powder
Contains aspartame, an artificial sweetener described as "possibly carcinogenic to humans" by the World Health Organization (WHO).
Also contains citric acid, an artificial color and artificial flavors.
Our verdict: Unhealthy
Fiber Thins
Composed of mostly whole food ingredients, and spices like cinnamon and nutmeg that provide health-promoting phytonutrients.
Also contains refined sugar and artificial flavors.
Our verdict: Unhealthy
While we don't currently recommend any Metamucil products, we consider Metamucil Premium Blend to be the healthiest product sold by the brand.
While this product contains citric acid and natural flavors, it's free of refined sugar, artificial color and artificial flavor.
Benefiber vs. Metamucil
Consumers are often curious about whether Benefiber or Metamucil is healthier, given that these are two of the most popular fiber supplements on the market.
We believe that Benefiber is the clearly superior option from a nutritional perspective, because it only contains one ingredient: wheat dextrin.
What dextrin is a soluble fiber processed from wheat grain.
The lack of questionable filler ingredients makes Benefiber the healthier option, and for individuals with no gluten sensitivity, Benefiber may be one of the best fiber formulations on the market due to its clean, simple and non-toxic formulation.
There are no questionable additive ingredients in Benefiber like artificial dye or artificial sweeteners.
In this section we’re only referring to the formulation of original Benefiber powder and not any of the brand's other products.
Metamucil vs. Miralax
Miralax is an over-the-counter (OTC) product used to treat constipation.
Because fiber can also stimulate a bowel movement, consumers are often curious about which product is more effective for treating constipation.
We believe that Miralax is more likely to be effective for treating constipation than Metamucil because it's formulated to support that outcome. Metamucil is not a laxative.
The active ingredient in Miralax is polyethylene glycol which was shown in a medical review to be effective for the treatment and management of constipation.
While we consider Miralax to be the better option for treating acute constipation, we would not recommend it overall as an alternative to Metamucil.
Miralax is used for a specific medical circumstance, not as a fiber replacement, and there may be health risks associated with its long-term use. Metamucil is the better option for consumers seeking a fiber supplement.
Our Clean Gut Health Picks
Manukora MGO 850+ is our top whole food gut health pick.
A 2024 clinical trial reported that manuka honey ingestion "correlates with beneficial modulation of gut microbiota composition."
MBG Organic Fiber Potency+ is our top gut health supplement.
MBG Organic Fiber Potency+ contains 100% soluble fiber, which was described as "one of the most important nutrients for the gut microbiota" in a clinical review published in the Molecules journal.
Both of the products recommended in this section are free of ingredients that we consider to be unhealthy.
Metamucil Pros and Cons
Pros:
- Provides effective fiber dose
- Should support gut health
- Mostly positive online customer reviews
- Premium Blend is relatively healthy
Cons:
- One Metamucil product was shown to have high lead levels in independent tests
- Company sued over lead levels
- Some products contain artificial flavors
- Some products contain artificial colors
- Some products contain citric acid
- Some products contain natural flavors
- Some products contain refined, added sugar
