What is psyllium husk, and what can it do for metabolic health?
This supplement is for more than GI issues. It also helps manage blood sugar, insulin, and LDL cholesterol.
Psyllium husk is nothing new. People have used the seed-derived soluble fiber for centuries as a digestive remedy to alleviate constipation and diarrhea. But recently, psyllium husk has shown potential to be more than just a GI fix, with some research suggesting it may lower cholesterol and support stable blood sugar. It’s also gained attention for its alleged ability to curb cravings and promote weight loss—some people even compare it to wildly popular GLP-1 receptor agonist drugs like Ozempic and Wegovy.
But can it really do all that? Here, we break down psyllium’s promising metabolic perks, who might consider trying it, and what to look for in a supplement.
What is psyllium husk?
Psyllium husk (also called blond psyllium and ispaghul) is a soluble fiber derived from the seeds of the shrub-like Plantago ovata plant, which is grown predominantly in India. Psyllium husk comes from the outer coverings, or husks, of psyllium seeds. The husks are typically ground into a uniform texture and sold in supplement form, either as a powder that can be mixed with liquids or as capsules.
Similar to chia seeds, psyllium husk forms a thick, viscous gel when combined with water or when it encounters fluids in the GI tract, which contributes to its health benefits.
How does psyllium husk affect metabolic health?
The most substantial evidence on psyllium husk is on its benefits for:
- Digestive health
- Blood glucose
- Cholesterol levels
Psyllium husk, digestion, and gut health
Psyllium husk is the great equalizer for digestion, helping alleviate both constipation and diarrhea due to its water-holding capacity. When consumed with plenty of fluids, psyllium husk absorbs water and swells. This helps bulk up and subtly soften stools, making them easier to pass if you’re experiencing constipation. Psyllium husk’s ability to absorb water in the GI tract can also help firm up loose stools and slow their movement through the intestines if you’re prone to mild to moderate diarrhea.
Psyllium husk is the only form of isolated fiber recommended by the American College of Gastroenterology for relieving IBS symptoms (which can include both constipation and diarrhea). And the American Gastroenterological Association recommends this “bulk-forming” laxative for chronic idiopathic constipation (that is, persistent constipation with no known cause).
There’s also evidence that psyllium can do more for your gut. While it’s often classified as a “non-fermentable, gel-forming fiber,” some evidence suggests gut bacteria ferment a portion of psyllium husk—meaning it has prebiotic properties. Prebiotics feed and promote the proliferation of good bacteria (probiotics) in your gut, contributing to the formation of fermentation byproducts called short-chain fatty acids (SCFAs). These SCFAs, including butyrate, play an integral role in supporting the health of your gut barrier and curbing inflammation. In turn, this supports metabolic health, as inflammation underlies many metabolic disorders.
In a small 2019 clinical trial, taking 21 grams of psyllium husk fiber per day for one week increased several beneficial microbes in the gut compared to a placebo, particularly for study participants with constipation. These people ended up with higher levels of Lachnospira, Roseburia, and Faecalibacterium bacteria*,* which are known producers of butyrate and were correlated with increased fecal water content. This evidence suggests that psyllium husk alters the gut microbiome in a way that helps alleviate constipation and promotes the production of beneficial SCFAs. Added bonus: Compared to highly fermentable fibers like inulin, psyllium is less likely to cause gas and bloating.
Psyllium husk, satiety, and blood glucose
Because psyllium husk swells into a thick, viscous gel as it travels through the GI tract, it can slow gastric emptying—the movement of partially digested food from the stomach into the small intestine—when taken with a meal. This slowing has two main benefits: It contributes to a feeling of satiety and supports healthy blood sugar balance. Other sources of soluble fiber can have a similar effect, but there’s some compelling research on psyllium husk.
In a 2016 study, participants consumed either 3.4, 6.8, or 10.2 grams of psyllium before breakfast and lunch for three days. All groups experienced reduced hunger and desire to eat and increased fullness between meals compared to the placebo. But, the two higher doses provided the most significant and consistent benefits.
Regarding glycemic control, a 2015 meta-analysis of 35 randomized controlled trials found that taking psyllium before meals significantly reduced fasting blood glucose and HbA1c (a measure of average blood sugar over the past three months) in people with Type 2 diabetes. This effect was supported by a 2016 clinical trial in which people with Type 2 diabetes consumed 7 grams of psyllium husk fiber before lunch and 3.5 grams before dinner daily. After eight weeks, study participants significantly lowered their fasting blood glucose (by 44 points), HbA1C, insulin levels, and HOMA-IR, a marker of insulin resistance. Typically, research has shown that psyllium’s glycemic benefits are greater among those with compromised metabolic function, but even among healthy people, studies have found that taking psyllium with a meal can help curb post-meal spikes in blood sugar and insulin.
Together, these benefits could translate to subtle weight loss in some people In a 2023 meta-analysis, researchers found that, on average, 10.8 grams of psyllium husk fiber per day (divided and taken before meals) decreased body weight by 4.6 pounds and waist circumference by 2.2 centimeters among participants with overweight and obesity after almost five months. Per the researchers, a combination of reduced insulin resistance due to improved glycemic control and caloric reduction due to increased satiety is the most likely explanation for these changes. However, improved insulin sensitivity seems to be the more substantial factor.
Psyllium husk and cholesterol levels
High blood levels of LDL cholesterol are associated with fatty plaque buildup in artery walls, which can promote atherosclerotic cardiovascular disease. Several studies have shown that consuming 6 to 15 grams of psyllium husk fiber daily may lower LDL cholesterol by 6 to 24 percent. (Note: Getting 5 to 10 grams of soluble fiber daily from any source has been shown to lower LDL by 5 to 11 mg/dL.) Additionally, in a 2018 meta-analysis of 28 clinical trials, psyllium intake was shown to lower LDL cholesterol and ApoB, a marker of all atherogenic (“plaque-promoting”) particles in the blood that’s considered a more accurate measure of cardiovascular disease risk.
Even if you currently take a statin medication to lower your cholesterol, it’s worth asking your doctor about psyllium since it could lower your dose. In a 2005 randomized controlled trial, patients taking 10 milligrams of simvastatin supplemented with psyllium husk experienced a drop in cholesterol equivalent to taking 20 milligrams of simvastatin alone.
Again, these benefits are mainly due to psyllium husk’s gel-forming properties. As it moves through the intestines, it helps trap and eliminate bile acids, which are composed primarily of cholesterol. Increased fecal elimination of bile acids (normally recycled by the body) means the liver must synthesize new bile acids to meet the body’s needs. This prompts the liver to take up more cholesterol from the bloodstream, thereby lowering circulating levels of LDL cholesterol and several other blood lipids. Additionally, researchers speculate that the SCFAs produced as a result of psyllium fiber fermentation in the gut may alter cholesterol metabolism and decrease cholesterol synthesis in part by interfering with the activity of the enzyme HMG-CoA reductase.
How much psyllium husk do you need?
You’re probably not consuming any psyllium husk through your diet, as it’s rarely found in everyday foods (except for a few high-fiber cereals). Psyllium husk is predominantly found as a supplement.
Because psyllium husk isn’t an essential nutrient, you don’t “need” to consume it to survive. However, it is a source of fiber (predominantly soluble), and most people fall woefully short on their fiber goals. The average American gets just 10 to 15 grams per day, while most Levels experts recommend around 50 grams. So, if you regularly struggle to hit your fiber quota through food alone, a psyllium supplement could help. Per the research above, you might also benefit from increasing your psyllium husk intake via supplements if you experience constipation or loose stools, are trying to balance blood sugar, or have elevated cholesterol levels.
Keep in mind: There’s no specific range of psyllium husk intake that is ideal for everyone or every benefit. There are, however, some suggestions we can pull from the research.
Per a 2024 research review, the most common dose of psyllium husk that’s been shown to have therapeutic effects for gastrointestinal conditions in clinical trials is 10 to 15 grams per day, divided into three doses of 3.5 to 5 grams before meals. This is generally in line with the doses and distribution used in the studies above to elicit other benefits related to satiety, blood sugar, and cholesterol.
If you are new to taking psyllium husk, start with a low dose. Try ½ teaspoon (3.4g) per day mixed in at least eight ounces of water or another beverage for your first week, then gradually work up to your desired dose. This should help reduce the likelihood of symptoms like gas and bloating while your body adjusts to the increased fiber load. For every 3 to 5 grams of psyllium husk taken, drink at least eight ounces of fluids, and make sure you’re drinking plenty of water throughout the day to stay hydrated and avoid constipation. You can also incorporate psyllium husk into recipes, like this flax bread from Beth Bollinger.
As always, it’s best to work with a medical professional to identify the optimal dose for you. Your provider can also help you determine if you need to avoid psyllium based on your current health status and medications. For example, if you have a bowel obstruction, esophageal stricture (narrowing of the esophagus), or difficulty swallowing, psyllium husk supplements are not for you. Psyllium also has the potential to bind to certain drugs (e.g., metformin, lithium, and certain antidepressants) in the GI tract and reduce their effectiveness, so additional dosing guidance from a professional is vital if you’re taking prescription medication.
What to know about psyllium husk supplements
Psyllium husk is primarily available as a supplement, typically as a loose powder or capsule form. Loose powders are generally preferable to capsules, as each capsule can only fit a small amount of total fiber (just 1 gram per three capsules for this option). So, you’d need to take a lot of them to hit a meaningful dose. Psyllium husk powder, on the other hand, is meant to be mixed with liquids and often contains five to seven grams of total fiber per serving.
While psyllium husk powder is preferred, not all powders are created equal. Many mainstream psyllium husk powder supplements, such as Metamucil, contain some combination of added sugars (up to 16 grams), artificial sweeteners, artificial colors, and artificial flavors. Your best choice is plain psyllium husk powder, which is simply ground-up psyllium husks with no additives, such as those from Konsyl and NOW. If you prefer a little flavor, brands like Bellway offer psyllium husk powder with added fruit powders, natural flavor, and monk fruit. Pro tip: For a less clumpy texture, quickly and thoroughly mix the powder and liquid. And keep in mind the longer you let the mixture sit, the thicker it becomes.
Many studies have shown the benefits of taking psyllium husk supplements before meals but consider your supplement and medication schedule. A good general rule is to take psyllium husk at least one hour before or two to four hours after taking other medications and supplements to ensure proper absorption. And as mentioned above, psyllium supplements may need to be avoided if you’re taking certain medications.
Psyllium husk powder is considered safe for daily use for up to 20 weeks for most people. If you are considering taking it longer, just consult with a medical professional. Finally, because different brands of psyllium husk powder may contain different amounts of fiber per serving (depending on the texture and other additives), always consider package dosing instructions along with your medical provider’s recommendations.
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