Glucomannan and Weight Loss: What the Science Actually Says

There are very few weight management ingredients in the UK supplement market that carry an authorised health claim from the European Food Safety Authority (EFSA) — and subsequently the GB NHC Register.

Glucomannan is one of them.

The authorised claim reads: Glucomannan in the context of an energy-restricted diet contributes to weight loss.

This claim is not marketing. It is a regulatory approval based on clinical evidence. The specific conditions are: 3g of glucomannan per day, taken in three 1g doses with 1–2 glasses of water before each main meal.

What is glucomannan?

Glucomannan is a natural dietary fibre derived from the konjac root (Amorphophallus konjac). It is water-soluble and has a particularly high viscosity — meaning it forms a thick gel when it absorbs water.

How does it work?

When consumed before a meal with water, glucomannan expands in the stomach. This creates a feeling of fullness (satiety) before eating. As a result, people following an energy-restricted diet may find it easier to manage portion sizes and calorie intake.

The key phrase is “in the context of an energy-restricted diet”. Glucomannan does not cause weight loss on its own. It supports people who are actively reducing their calorie intake by helping them feel fuller before meals.

Why SLIM-BRN uses glucomannan in a drink format

SLIM-BRN delivers glucomannan as a pre-meal drink powder — which is actually the optimal format. The glucomannan is mixed with water, consumed before eating, and then begins to expand in the stomach. A capsule format requires enough liquid to dissolve effectively; a drink powder ensures this happens correctly every time.

This is an authorised health claim under the GB Register of Nutrition and Health Claims.
Always use as part of a varied and balanced diet and healthy lifestyle.