Glucomannan 575 mg Veg Capsules

NOW Foods Glucomannan is the no-frills option in this category. Each three-capsule serving provides 1,725 mg of glucomannan, a soluble, highly absorbent fiber from konjac root, and nothing else of note. NOW suggests three capsules one to two times a day with at least 8 oz of water, 30 to 45 minutes before a meal, so the fiber can swell and add a feeling of fullness.

Glucomannan is one of the more plausible weight-management fibers, but the payoff is small. A 2014 meta-analysis of eight randomized trials found no statistically significant difference in weight loss versus placebo (about 0.2 kg). A broader 2021 meta-analysis did find a statistically significant 1.27 kg difference, but the authors noted that it fell short of their 2.5 kg threshold for clinical significance. Its more reliable roles are adding soluble fiber and supporting regularity, and buyers most often say they feel fuller and eat less.

The main safety point is on the label: without enough liquid, the capsules can swell in the throat and cause choking, so anyone who has had swallowing difficulties or esophageal narrowing should avoid it. NOW also advises checking with a physician if you take medication. Trials have reported abdominal discomfort, diarrhea and constipation, and some buyers mention cramps or bloating.

NOW is a family- and employee-owned manufacturer founded in 1968. This product is made under an NPA A-rated GMP certification and is non-GMO and vegan, with no gluten, soy or dairy ingredients. At about $16.50 for 180 capsules (60 servings), it's roughly 28 cents a serving, an inexpensive way to see whether a pre-meal fiber helps your appetite.