Metamucil vs Citrucel: Which Is Better? (2026)

Metamucil and Citrucel are both fiber supplements. They both bulk up your stool, they both take 12-72 hours, and they're both safe for daily long-term use. So why does the choice matter? Because of one word: gas.

What Is the Difference Between Their Fiber Types?

Metamucil uses psyllium husk, a natural plant fiber from the Plantago ovata seed. When psyllium reaches your large intestine, gut bacteria partially ferment it. That fermentation is actually beneficial — it feeds good bacteria and produces short-chain fatty acids that nourish your colon lining. But it also produces gas. Methane, hydrogen, the works. For many people, the first 1-2 weeks on Metamucil mean noticeable bloating, flatulence, and abdominal discomfort.

Citrucel uses methylcellulose, a semi-synthetic fiber derived from plant cellulose. The key difference: methylcellulose is non-fermentable. Your gut bacteria essentially can't touch it. It passes through your system doing its bulking job without producing any gas whatsoever. No adjustment period, no bloating, no awkward moments.

Both fibers work through the same basic mechanism — they absorb water, swell into a gel, add bulk to stool, and stimulate natural peristalsis. The end result is the same soft, formed stool that's easy to pass. The journey getting there is where they differ.

Which Has Better Side Effects?

Metamucil's side effects are concentrated in the first two weeks: bloating, gas, mild cramping, and a feeling of fullness that some people find uncomfortable. Most of these symptoms fade as your gut microbiome adapts. The other common complaint is texture — Metamucil's psyllium forms a thick, slightly gritty gel that some people find unpleasant to drink. You have to mix it quickly, drink it quickly, and chase it with more water.

Citrucel's side effects are remarkably few. The methylcellulose powder mixes more smoothly than psyllium, though it still thickens if you wait too long. The main risk with Citrucel (and Metamucil) is the same: not drinking enough water. Fiber without adequate hydration can actually worsen constipation by creating a dry, bulky mass that's harder to pass. At least 8 ounces of water with each dose, plus extra fluids throughout the day.

Does Only Metamucil Lower Cholesterol?

This is where Metamucil pulls ahead for certain people. Psyllium husk has an FDA-approved health claim for cholesterol reduction. The soluble gel traps bile acids in your intestines and carries them out of your body. Your liver then pulls LDL cholesterol from your bloodstream to synthesize replacement bile acids. Studies show 5-10 grams of psyllium daily can lower LDL cholesterol by 5-7%. That's meaningful — enough that some doctors recommend it as a first step before statins for borderline cholesterol levels.

Citrucel's methylcellulose does not have this effect. If your doctor has suggested fiber to help with cholesterol, Metamucil (or generic psyllium husk) is the only OTC fiber supplement with clinical evidence supporting that specific benefit.

How Do They Taste and Feel to Drink?

If you're taking something every day, how it tastes matters. Metamucil comes in flavored powders (Orange is the classic), sugar-free options, capsules, and gummies. The powder has a distinctive grainy texture that divides people — some don't mind it, others gag. The capsules avoid the texture issue but require swallowing 5-6 large capsules per dose.

Citrucel also comes in powder (Orange flavor) and caplet form. The powder generally mixes smoother than Metamucil with less grittiness, though it still thickens quickly. The caplets are a convenient option if you dislike drinking fiber.

Both products need to be consumed immediately after mixing. Wait more than 30 seconds and you'll have a gel glob in your glass that's genuinely difficult to drink.

Which Is Better for IBS Patients?

If you have IBS, gas and bloating aren't just uncomfortable — they can trigger a full flare. The fermentation from psyllium can push IBS-sensitive intestines past their threshold, causing pain, distension, and altered bowel habits. Many gastroenterologists specifically recommend methylcellulose (Citrucel) over psyllium (Metamucil) for IBS patients because of the non-fermentable advantage.

That said, some IBS patients do fine on Metamucil after a gradual ramp-up period. The prebiotic effect of psyllium fermentation may even benefit IBS over the long term. But if you're trying fiber for the first time with IBS, starting with Citrucel is the lower-risk move.

When Should You Choose Each One?

Metamucil wins for: people who want the cholesterol-lowering benefit, those who tolerate the initial gas phase, anyone looking for the most-researched fiber supplement, and people who prefer the widest variety of product formats (powder, capsules, gummies).

Citrucel wins for: gas-sensitive individuals, IBS patients, anyone who tried Metamucil and couldn't tolerate the bloating, and people who want a smoother-mixing powder with no adjustment period.

How Do Their Prices Compare?

Metamucil runs $15-35 depending on format and size, with generic psyllium husk available for significantly less ($8-15). Citrucel costs $12-28 for the name brand, with generic methylcellulose also available at lower prices. Per-day costs are similar for both — roughly $0.30-0.60 for name brand, less for generics. Price should not be the deciding factor here; the gas question should be.