Konjac is a perennial tuber plant native to the forests of Southeast Asia, cultivated for over 2,000 years in Japan, China and Indonesia. Glucomannan, the root’s main active component, is a unique soluble fibre able to absorb up to 50 times its volume in water. Once ingested with a large glass of water, it forms a bulky gel that fills the stomach, prolongs the feeling of fullness, and slows the intestinal absorption of sugars and fats — a simple mechanical property that makes it one of the most studied and recognised natural appetite-control fibres among European health authorities. Each capsule provides 550 mg of Konjac rhizome powder at over 90% glucomannan.

Konjac glucomannan carries health claims officially validated by EFSA (the European Food Safety Authority): “Glucomannan contributes to weight loss in the context of an energy-restricted diet” at 3 g of glucomannan per day, in 3 doses of 1 g with 1–2 glasses of water before meals; and “Glucomannan contributes to the maintenance of normal blood cholesterol concentrations” at 4 g per day. These claims are backed by numerous clinical studies showing that glucomannan, by forming a viscous gel in the stomach, prolongs satiety, reduces spontaneous food intake and limits intestinal absorption of fat and cholesterol. For best results, Konjac should be taken before each meal with a large glass of water, as part of a broader approach combining a balanced diet and regular physical activity.

Glucomannan is a non-digestible soluble fibre. Once taken with a large glass of water, it swells in the stomach and forms a bulky gel that stretches the stomach walls — a mechanical effect that activates satiety receptors and sends the brain a fullness signal similar to a substantial meal. The result: appetite decreases, natural portions shrink, and snacking between meals fades. In the gut, the gel also slows carbohydrate and fat absorption. Unlike chemical appetite suppressants, glucomannan acts purely through this mechanical effect, with no stimulant and no effect on the central nervous system.

Maintenance: 2 capsules before each main meal (morning, midday, evening), with 1–2 large glasses of water (250 ml minimum). Intensive support: up to 6 capsules a day, split before main meals to reach the EFSA-validated 3 g of glucomannan. Swallow the capsules 15–30 minutes before the meal with a large glass of water, then drink a second glass right after — this double intake of water is essential for the gel to form correctly in the stomach rather than the oesophagus.

Always take Konjac with plenty of water to avoid any risk of oesophageal obstruction. Not for use in children under 12, people with swallowing difficulties, or digestive strictures. If on medication, ask a healthcare professional for advice, as Konjac can slow the absorption of certain medicines — take at least 2 hours apart. This food supplement is not a substitute for a varied, balanced diet and a healthy lifestyle. Do not exceed the recommended dose. Keep out of reach of children.

Does Konjac really help with weight loss?

Konjac glucomannan is one of the few slimming actives whose efficacy, as part of a calorie-controlled diet, is officially recognised by EFSA. At 3 g a day before meals, it contributes to weight loss by reducing appetite and fat absorption.

How long before I see results?

Satiety effects can be felt from the first dose. For weight loss, allow around 4–8 weeks at 6 capsules a day, combined with a calorie-controlled diet and regular activity.

Does Konjac have side effects?

Generally well tolerated. Some digestive discomfort (bloating, gas) may appear early in the course and settles afterwards. Start with 2 capsules a day and increase gradually, always with a large glass of water.

Herba Barona is an independent specialist supplement shop in the heart of Paris — established in 2006. What you order is genuinely on our shelves: we ship from our own stock, with no dropshipping and no long waits.

Visit us at 10 rue Théophile Roussel, Paris 12 — or use Click & Collect and pick up your order in-store. We also deliver across France and Europe. Friendly, expert advice in English from our team.

Where is the shop?

Herba Barona is at 10 rue Théophile Roussel, 75012 Paris — a two-minute walk from Ledru-Rollin (line 8), close to Bastille. Open Tuesday to Saturday, 9:30 am–6:30 pm.

Can I order online or collect in store?

Yes. We ship across France and Europe under the same conditions as our French store, or choose Click & Collect to pick up your order for free at our Paris shop.