Stool form and regularity
NOW Foods Glucomannan 575 mg Capsules
Konjac root fiber in capsules, a bulk-forming fiber sold mainly for fullness, with a small constipation record.
- Format
- Capsule
- Type
- Fiber
- Cost
- $0.55 a day
- Customer rating
- 4.2 out of 5 from 3,906 ratings from Amazon
What customers consistently report
- Feeling full between meals, which is why most people buy it
- Regularity for those who take the full dose with enough water
- A cheap capsule that avoids a powder
Those are the themes that recur across the reviews. High review confidence — 4.2 from 3,906 Amazon ratings, with most buyers using it for appetite rather than regularity.
Why it might work
Glucomannan absorbs many times its weight in water and forms a thick, viscous gel, which is why it fills the stomach and why it adds soft bulk to stool. It is fermented in the colon more slowly than inulin. The same swelling that makes it work is what makes it dangerous without liquid: it must be swallowed with a full glass of water and never taken dry.
What the research supports
Ingredient-level evidence, thin for constipation. A diet-controlled crossover study in seven constipated adults found 4.5 g of konjac glucomannan a day raised bowel movements from 4.1 to 5.3 a week and improved colonic bacteria. A 2025 randomized trial in athletes with functional constipation reported improved symptoms. The larger evidence base for glucomannan is in weight management, where meta-analyses find small effects. No trial of this NOW product was found.
What the label discloses
Each capsule supplies 575 mg of glucomannan from konjac root (Amorphophallus konjac); NOW states the product is vegan, non-GMO, soy-free, nut-free, dairy-free, egg-free, halal and made without gluten, with NPA A-rated GMP certification. The label carries the choking warning prominently. No third-party testing certificate is published.
Who this tends to suit
We match this product to people reporting constipation and irregular bowel habits. It fits someone whose priority is regularity or a steady daily routine. Whether it is the best fit for you depends on the rest of your answers — what you have already tried, what format you will take, and anything that has to be ruled out.
Where it may not fit
The label supports vegan, gluten-free, dairy-free, no added sweeteners and minimal ingredient list. We flag this product for anyone pregnant or breastfeeding, and the quiz removes it rather than recommending it in those cases. That is a caution about who should be deciding, not a claim about the product. A capsule only works if you will take it as often as the label directs.
Side effects and what to be aware of
The label dose is six capsules a day, three at a time with a full glass of water, and the warning is not optional: glucomannan swells enormously and has caused throat blockages when taken with too little liquid. Not for anyone with swallowing difficulty or a narrowed esophagus. Cramping and bloating are reported. The constipation evidence is very small.
Before you take this. Speak to a doctor or pharmacist first if you are pregnant or breastfeeding. Nothing on this page is medical advice, and no supplement diagnoses, treats, cures or prevents disease.
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Others we researched for the same job
These sit in the same role as NOW Foods Glucomannan 575 mg Capsules — stool form and regularity — so they are the sensible things to weigh it against.
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Related reading
Background on how this type of product works, read from the trial evidence.