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 was Metamucil shown in independent testing to contain relatively high lead levels? Does Metamucil contain healthy ingredients? Which Metamucil product has the healthiest formulation? And how do real customers rate and describe the effects of Metamucil supplements?
In this article we’ll answer all of these questions and more, as we share a third-party test result which found Metamucil to have concerningly high lead levels.
We'll analyze the ingredients in some of Metamucil's most popular supplements to give our pick for the healthiest option.
We'll also discuss the potential for side effects, feature unsponsored customer reviews and provide a cost comparison to show which retailer sells Metamucil for the best price.
Finally, we'll explain why Metamucil was sued in 2023, and compare Metamucil to Benefiber (another popular fiber brand) and Miralax (a laxative).
Lead Contamination Issues
Metamucil's 4-in-1 Fiber powder Orange flavor was found to contain relatively high levels of lead in testing conducted by an independent third-party organization called ConsumerLab.
ConsumerLab found up to 14.6 micrograms (mcg) of lead per serving.
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 documented by ConsumerLab 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.
As reported above, the testing also found "12 insect fragments" per 25 grams (g) of Metamucil fiber powder.
The ingredients in Metamucil's fiber powder are shown above.
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, but 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.
Real People Try Metamucil
A YouTube creator named Ciara Lynn explains whether or not Metamucil caused her to lose weight:
A TikTok creator named Stefanie Renee suggests that Metamucil is a good choice for people who deal with regular gas and bloating:
@stefanie.renee.salyers If you’re seeing this, you probably really need to start taking Metamucil… This will get you, so regular so fast. 10 out of 10 recommend taking Metamucil every morning for regular poops 💩 #ibs #metamucil #ibstok #constipation #health #vitamins #supplements #fiber #holistic ♬ original sound - Stefanie Renee
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
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.
Why Was Metamucil Sued?
In 2023, Metamucil was sued in a class-action lawsuit filed in New York federal court.
The plaintiff alleged that Metamucil contains dangerous levels of lead, according to Top Class Actions.
At the time of updating this article, it's unclear to us if this lawsuit is ongoing.
We don't believe this lawsuit provides any additional information that can help guide consumers to an informed health decision.
We had already shared our concerns about the lead levels in Metamucil more than a year before this lawsuit was filed, and we can't find any evidence that lead contamination is an ongoing issue for Metamucil.
ConsumerLab doesn't appear to have tested any new batches of Metamucil supplements since the lawsuit, or since our initial publication of this article.
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.
Real Customers Review Metamucil
Amazon is a better resource for honest customer reviews than a brand's website in our opinion.
Metamucil Sugar-Free Fiber Powder is the brand's most-reviewed product on Amazon, with over 28,000 reviews and an average review rating of 4.7 out of 5 stars at the time of updating this article.
The top positive review from a verified purchaser comes from a user named "Chin Music" who gives the product a 5/5 star rating, and likes both the taste and functional benefit:
"No matter what I eat, as long as I've taken my Metamucil, I do not have to worry about being irregular. The nice thing is that it tastes just like Tang which takes me back to my childhood!"
The top negative review from a verified purchaser is written by a user named "Savannah" who gives the product a 1/5 star rating, and claims it worsened constipation:
"Idk if I somehow used this wrong but I was even more constipated when I used this. I suggest seeing a doctor and getting a recommendation before you try."
Metamucil currently has an average review rating of 4.6 out of 5 stars on Google.
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
MBG Organic Fiber Potency+ is our top fiber pick because it's certified organic, provides 7 g of fiber per serving and costs under $1.85 per serving at the time of updating this article.
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.
Bulletproof Express 3-in-1 Probiotic is our top value probiotic supplement, because it costs only $1.20 per serving at the time of updating this article.
Probiotics "can improve in the immune, gastrointestinal...health systems in healthy adults" according to a 2019 medical review.
"...many studies demonstrated that VSL#3 has a beneficial effect on obesity and diabetes, allergic diseases, nervous systemic diseases, AS, bone diseases, and female reproductive systemic diseases."
All of the products recommended in this section are entirely free of ingredients that we consider to be unhealthy or unsafe.
Where to Buy Metamucil for the Best Price
Metamucil products are sold at a variety of online retailers.
Here's a price breakdown for a one-time purchase of two of the brand's most popular products at the time of updating this article:
Metamucil Sugar-Free Fiber Powder (180-count)
CVS: $43.29 (free shipping, link)
Walmart: $31.82 (plus shipping, link)
Amazon: $31.82 (free shipping, link to official Amazon listing)
Metamucil Premium Blend Fiber Powder (180-count)
Amazon: $39.99 (free shipping, link to official Amazon listing)
Amazon has the best prices on Metamucil supplements currently.
The Sugar-Free Fiber Powder is 26% cheaper at Amazon than CVS, and Amazon appears to be the only retailer of the value-sized version of the Premium Blend.
Pros and Cons of Metamucil
Here are the pros and cons of Metamucil in our opinion:
- Provides effective fiber dose
- Should support gut health
- Mostly positive online customer reviews
- Premium Blend is relatively healthy
- One Metamucil product was shown to have high lead levels in ConsumerLab study
- 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