Citrucel is a methylcellulose-based fiber supplement designed to relieve occasional constipation and support regularity. In this Citrucel review, the short version is this: it’s a gentle, 100% soluble fiber that generally doesn’t cause the extra gas and bloating associated with fermentable fibers like psyllium or inulin. It works reliably for mild to moderate constipation, but it isn’t a fit for people who need fiber for cholesterol support, blood sugar management, or gut microbiome benefits, since methylcellulose isn’t fermented by gut bacteria the way other fibers are.
If you want fiber that’s easy on digestion and won’t leave you gassy, Citrucel is a solid, well-studied option. If you’re looking for a fiber that also feeds your gut bacteria or lowers cholesterol, you’ll want to look at psyllium husk or acacia fiber instead.
Table of Contents
What Is Citrucel?
Citrucel is an over-the-counter fiber supplement made from methylcellulose, a plant-derived, non-fermentable soluble fiber. It’s manufactured by GSK Consumer Healthcare and sold in the same aisle as other bulk-forming laxatives like Metamucil and Benefiber.
Unlike psyllium husk (the fiber in Metamucil) or wheat dextrin (the fiber in Benefiber), methylcellulose is a semi-synthetic fiber. It’s derived from plant cellulose but chemically modified so your gut bacteria can’t break it down. That single difference explains almost everything people notice — and don’t notice — when they use it.
Citrucel is sold in a few different forms:
- Citrucel Caplets — 500 mg of methylcellulose per caplet, taken with water
- Citrucel Powder (Orange Flavor) — mixed into a beverage, 2 g of methylcellulose per heaping tablespoon
- Citrucel Sugar-Free Powder — same formula without added sugar, sweetened with alternatives
<cite index=”10-1″>Each two-caplet dose of the caplets contains one gram of methylcellulose, compared with two grams in a single scoop of the powder.</cite>
How Citrucel Works
Methylcellulose is a bulk-forming fiber. It absorbs water in the intestines and swells into a soft, gel-like mass. This does two things:
- Adds bulk to stool, which stimulates the intestinal walls to contract and move waste along
- Softens stool, making it easier to pass without straining
Because methylcellulose isn’t fermented by colon bacteria, it doesn’t produce the gas byproducts that fermentable fibers do. That’s the core reason people choose Citrucel over psyllium: it’s gentler on a sensitive gut, but it also means it doesn’t feed beneficial bacteria the way a prebiotic fiber would.
<cite index=”8-1″>Citrucel generally produces a bowel movement within 12 to 72 hours of use.</cite> That’s a wider window than some people expect, so patience matters in the first few days.
Citrucel Ingredients
Here’s exactly what’s in the caplet version, based on the product label.
| Ingredient Type | Ingredient | Purpose |
| Active | <cite index=”3-1″>Methylcellulose (500 mg per caplet)</cite> | Bulk-forming soluble fiber |
| Inactive | <cite index=”3-1″>Crospovidone</cite> | Disintegrant, helps caplet break down |
| Inactive | <cite index=”3-1″>Dibasic calcium phosphate</cite> | Filler/binder |
| Inactive | <cite index=”3-1″>FD&C Yellow No. 6 aluminum lake</cite> | Coloring agent |
| Inactive | <cite index=”3-1″>Magnesium stearate</cite> | Lubricant for manufacturing |
| Inactive | <cite index=”3-1″>Maltodextrin</cite> | Filler |
| Inactive | <cite index=”3-1″>Povidone</cite> | Binder |
| Inactive | <cite index=”3-1″>Sodium lauryl sulfate</cite> | Surfactant, aids dissolution |
A few things worth flagging that most review pages skip:
- The yellow dye and sodium lauryl sulfate are only in the caplets, not necessarily the powder — if you’re sensitive to dyes or surfactants, the powder may be the better pick.
- Citrucel caplets are gluten-free, but always check the current label since manufacturers occasionally reformulate.
- <cite index=”7-1″>Each caplet also contains 10 mg of calcium</cite> from the dibasic calcium phosphate filler — a minor detail, but worth knowing if you’re tracking calcium intake closely.
Citrucel Dosage: How to Take It Correctly
Getting the dosage right is where most negative reviews actually originate — people either take too little to notice an effect, or too much too fast and get uncomfortable.
Caplets:
| Age Group | Starting Dose | Maximum Per Day |
| Adults & children 12+ | 2 caplets | 12 caplets |
| Children 6–12 | 1 caplet | 6 caplets |
| Under 6 | Consult a physician | — |
<cite index=”6-1″>Take each dose with 8 oz. of liquid, and you can increase gradually up to 4 caplets per dose as needed.</cite>
Powder: One heaping tablespoon (orange) or rounded tablespoon (sugar-free) mixed into 8 oz of liquid, up to a few times daily depending on the product directions.
A practical tip competitors rarely mention: start at the lowest dose for 3–5 days before increasing. Ramping up too quickly is the single most common cause of temporary bloating with any fiber supplement, methylcellulose included.
<cite index=”10-1″>Laxative products like Citrucel shouldn’t be used for longer than one week unless directed by a physician</cite> — though in practice, many people use daily fiber supplements long-term under a doctor’s guidance for maintenance, not acute constipation. If you plan to use it regularly, that’s a conversation worth having with your doctor rather than assuming it’s automatically fine.
Pros and Cons of Citrucel
| Pros | Cons |
| 100% soluble fiber — gentle on digestion | Not fermented, so no prebiotic/gut-microbiome benefit |
| Generally doesn’t cause excess gas or bloating | Slower onset (12–72 hours) than some people expect |
| Available in caplet and powder forms | Caplets contain artificial dye and several fillers |
| No mixing required with caplets | Doesn’t have strong evidence for lowering cholesterol, unlike psyllium |
| Clinically studied and widely available OTC | Requires adequate water intake — risk of choking if taken dry or with too little liquid |
| Sugar-free powder option available | Multiple caplets needed to match one scoop of powder |
Citrucel Side Effects
Citrucel is generally well tolerated, but side effects can happen, especially early on or with rapid dose increases:
- Mild bloating or fullness
- Stomach cramping
- Temporary gas (less common than with psyllium, but possible)
- Choking or throat blockage if taken without enough liquid
<cite index=”8-1″>The label specifically warns that taking this product without adequate fluid may cause it to swell and block the throat or esophagus, which can cause choking, and advises against use if you have difficulty swallowing.</cite> <cite index=”8-1″>If you experience chest pain, vomiting, or difficulty swallowing or breathing after taking it, that warrants immediate medical attention.</cite>
This is a genuine safety point, not boilerplate — always take Citrucel with a full 8 oz glass of water or the recommended liquid amount, and never take it dry.
This article is for educational purposes only and isn’t a substitute for medical advice. If you have a chronic digestive condition or take other medications, talk to your doctor or pharmacist before starting Citrucel, since fiber supplements can affect the absorption of certain medications.
Who Citrucel Is a Good Fit For
- People whose constipation is triggered by fermentable fibers (psyllium, inulin) causing gas or bloating
- Anyone who prefers a fiber that doesn’t require refrigeration or mixing (caplets)
- People managing occasional, mild-to-moderate constipation
- Those on a sugar-restricted diet (sugar-free powder option)
Who Should Consider a Different Fiber Supplement
- Anyone hoping fiber will also help lower cholesterol — psyllium husk has stronger evidence here
- People wanting a fiber that feeds gut bacteria (a prebiotic effect) — look at inulin or acacia fiber
- People with difficulty swallowing pills or capsules, who may prefer a different fiber powder
- Anyone sensitive to artificial dyes, who may want to check the best natural fiber supplement options instead
Citrucel vs. Other Fiber Supplements
Most reviews only rate Citrucel in isolation. Here’s how it actually stacks up against the two fibers people compare it to most.
| Feature | Citrucel (Methylcellulose) | Metamucil (Psyllium Husk) | Benefiber (Wheat Dextrin) |
| Fermentable by gut bacteria | No | Yes | Yes |
| Gas/bloating risk | Low | Moderate–higher | Low–moderate |
| Cholesterol-lowering evidence | Limited | Stronger | Limited |
| Dissolves clear in liquid | No (cloudy) | No (thickens) | Yes, dissolves clear |
| Onset time | 12–72 hours | 12–72 hours | 12–72 hours |
| Best for | Gas-sensitive users | General regularity + heart health | Mixing into food/drink discreetly |
For a deeper side-by-side, see our full Citrucel vs. Metamucil and Benefiber vs. Citrucel comparisons.
Common Mistakes People Make With Citrucel
- Not drinking enough water. This is the top cause of both poor results and choking risk.
- Expecting overnight results. With a 12–72 hour window, judging it after one dose isn’t a fair test.
- Jumping straight to the max dose. Slower titration avoids most bloating complaints.
- Using it for cholesterol or gut-health goals. Methylcellulose isn’t the right tool for that job — see our guide on soluble vs. insoluble fiber to understand why fiber type matters for different goals.
- Using it long-term without medical guidance. Fine for many people, but worth checking in with a doctor if it becomes a daily habit rather than occasional use.
What Real Users Report
Across pharmacy and drug-review sites, a consistent pattern shows up: people who switched to Citrucel from psyllium-based products most often cite less gas and bloating as the reason they stayed with it. The most common complaints are the slower onset time and the number of caplets needed to reach an effective dose. Powder users tend to report a milder, more neutral taste compared with older formulations, though taste preference is understandably subjective.
Citrucel FAQs
Is Citrucel better than Metamucil? Neither is universally “better” — it depends on your goal. Citrucel tends to cause less gas because it isn’t fermented, but Metamucil’s psyllium husk has more research behind it for cholesterol support. If gas and bloating are your main concern, Citrucel is usually the more comfortable choice.
How long does it take for Citrucel to work? Generally between 12 and 72 hours. Don’t judge effectiveness after a single dose.
Can I take Citrucel every day? Many people do use fiber supplements daily for maintenance, but the label is written around short-term, occasional use. If you want to take it long-term, run it by your doctor first.
Does Citrucel cause bloating? Less often than fermentable fibers like psyllium or inulin, since methylcellulose isn’t broken down by gut bacteria. Some initial bloating is still possible, especially if you increase your dose too quickly.
Is Citrucel safe to take with medications? Fiber supplements can interfere with how some medications are absorbed. As a general rule, take other medications at least an hour before or a couple of hours after your Citrucel dose, and confirm timing with your pharmacist.
What’s the difference between Citrucel caplets and powder? They contain the same active ingredient, but the caplets include added fillers, a dye, and a surfactant that the powder doesn’t necessarily contain. The powder also requires mixing and gets cloudy rather than dissolving clear.
Is Citrucel a prebiotic? No. Because methylcellulose resists fermentation by gut bacteria, it doesn’t function as a prebiotic the way inulin or acacia fiber do.
Final Verdict
This Citrucel review comes down to one clear takeaway: Citrucel is one of the gentlest bulk-forming fiber options available, and it earns its reputation as the go-to choice for people whose digestive system reacts badly to gassier fibers. It’s not the most versatile fiber supplement on the market — it won’t move the needle on cholesterol or gut bacteria diversity — but for straightforward relief of occasional constipation without the bloat, it does exactly what it promises.
If your priority is comfort and predictability, Citrucel is worth trying. If your goals extend beyond regularity into heart health or gut health, pair this review with our guide on how to choose a fiber supplement to find the better match for your needs.
This article is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional before starting a new supplement, especially if you have an existing health condition or take medication.
