Psyllium vs Metamucil is mostly a question of what comes with the fiber. Metamucil's powders and capsules are psyllium husk, the same fiber sold plain by other brands; the powder adds maltodextrin, flavor, a sweetener and color. Metamucil's Fiber Gummies are different: their label lists no psyllium at all, but inulin and soluble corn fiber.
This guide compares the labels, the grades and the cost, and sums up what the human studies show for psyllium itself. For the doses that worked, when to take it and its side effects, see our psyllium page.
Psyllium vs Metamucil at a Glance
From the labels of the products we graded, with each one's tier for the goal it was graded for:
| Product | Fiber on the label | Also on the label | Graded for | Tier | Cost a month |
|---|---|---|---|---|---|
| Metamucil 4-in-1 Sugar-Free Orange Powder | Psyllium husk, 6 g fiber per serving | Maltodextrin, citric acid, orange flavor, aspartame, Yellow 6 | Regularity | 2 | $6.12 |
| Metamucil Psyllium Husk Capsules | Psyllium husk, 2 g fiber per 5 capsules | Gelatin | Weight and Metabolism | 2 | $18 |
| Metamucil Fiber Gummies | No psyllium: inulin and soluble corn fiber, 5 g fiber per 3 gummies | Xylitol, pectin, Bacillus coagulans, colors from vegetable extracts | Regularity | 4 | $14.99 |
| Konsyl Original Psyllium Husk | Psyllium husk, 5 g fiber per teaspoon | Nothing else | Digestion and Bloating | 2 | $9.14 |
| NOW Psyllium Husk Powder | Psyllium husk, 7 g fiber per tablespoon | Nothing else | Regularity | 3 | $12.62 |
| NOW Psyllium Husk Caps | Psyllium husk, 1.1 g fiber per 3 capsules | Capsule shell, stearic acid | Regularity | 3 | $6.12 |
A tier grades a product for one goal on the human studies of its ingredients at the dose on its label; it is not a grade of the brand. The products are ranked on our Regularity page.
What the Human Studies Show for Psyllium
Regularity: in the human studies we graded, psyllium showed a clear improvement in 2 meta-analyses, from 3.4 g a day.
Gas, bloating and irregular bowels: a clear improvement in 5 meta-analyses, the largest of 1,904 people, from 7.5 g a day.
Cholesterol: across 28 trials of 1,924 people, about 10 g of psyllium a day lowered LDL cholesterol by 0.33 mmol/L, about 13 mg/dL (Jovanovski 2018).
Blood sugar: across 35 trials, psyllium lowered fasting blood sugar in proportion to how high it was to begin with: no change in people with normal readings, a modest fall in people just above normal, and the largest fall in people already taking meds for their blood sugar (Gibb 2015).
The gummies' fiber, inulin, is a different fiber with different studies: in the human studies we graded, inulin showed no effect for digestion and bloating across 56 studies. See the inulin page.
Plain Psyllium or Metamucil: What Differs
Additives. The sugar-free powder adds maltodextrin (a starch), aspartame, flavor and Yellow 6. Plain husk powders list only psyllium.
Fiber per dose. Capsules carry little fiber each: 5 Metamucil capsules hold 2 g and 3 NOW capsules 1.1 g, against 5 to 7 g in a spoonful of powder.
Cost. Among the products we graded, the powders cost $6 to $13 a month, the Metamucil capsules $18 and the gummies $15.
How to take it. The powder labels say to mix each dose into 8 to 12 oz of liquid; NOW's also says to drink plenty of fluids and to start small and build up over several weeks.
If you take meds: fiber can slow how some meds are absorbed, so take it apart from them and check the timing with your doctor or pharmacist. See our guide to supplement and med interactions.
Which Fits Your Stack
Rala, the AI behind Reverse Age Lab, ranks the fiber you take against the human studies for your goals, times it apart from your meds and builds one Daily Protocol with food and supplements together. Build my protocol, with my fiber timed for me.
Is this medical advice? No. This guide sets out the product labels and the published research on psyllium; it is not a diagnosis, and Rala isn't a medical device or a clinician. Talk to your doctor before you start a fiber supplement, especially if you take meds.
Frequently Asked Questions
Is Metamucil just psyllium?
Metamucil's powders and capsules use psyllium husk as their fiber; the powders add maltodextrin, flavor, a sweetener and color. Metamucil's Fiber Gummies contain no psyllium: their fiber is inulin and soluble corn fiber.
Are Metamucil gummies the same as the powder?
No. The gummies' label lists inulin and soluble corn fiber, not psyllium, so the psyllium studies don't apply to them. In the human studies we graded, inulin showed no effect for digestion and bloating.
Is plain psyllium husk cheaper than Metamucil?
Among the products we graded, the Metamucil sugar-free powder and NOW's capsules were the cheapest at about $6 a month; plain husk powders cost $9 to $13 and the Metamucil capsules $18.
Sources
Jovanovski E, Yashpal S, Komishon A et al. Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials. American Journal of Clinical Nutrition, 2018. PubMed.
Gibb RD, McRorie JW Jr, Russell DA et al. Psyllium fiber improves blood sugar control in proportion to how high it was: a meta-analysis. American Journal of Clinical Nutrition, 2015. PubMed.
