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Konjac Forte, a concentrated Glucomannan formula

flacon-konjac-forteKONJAC FORTE, a product that promises rapid and lasting weight loss thanks to a very popular ingredient at the moment, konjac.

According to the official website, Konjac Forte is “recommended by leading nutritionists”.. So, is Konjac Forte effective or not? Answer in our survey…

Konjac Forte presentation and promises

Konjac Forte comes in the form of hyper-concentrated capsules containing 500mg each of glucomannan, to be taken at a rate of 6 capsules a day. These 6 slimming pills provide a dose of 3 grams of glucomannan per day.

The official website backs up the quality of its product with an announcement from EFSA (European Food & Safety Authority), stating:

“Taking 3 grams of glucomannan (konjac extract) per day contributes to weight loss.”

After verification, we confirm that the EFSA is indeed behind such claims. You can read this statement directly on the EFSA website.

(Source: EFSA. European Food Safety Authority. EFSA Journal 2010; 8(10): 1798. 27pp. doi : 10.2903/j.efsa.2010.1798).

The benefits of Konjac Forte according to the official website:

  • Traps fats and sugars ;
  • Eliminates cravings ;
  • Promotes intestinal transit ;
  • Eliminates constipation;
  • Absorbs 100 times its volume of water;
  • Is hyper-concentrated.

The site explains its low prices on the basis of the absence of intermediaries and the fact that the konjac is selected directly in China, with the highest possible quantity of glucomannan.

Konjac Forte, by Perfoline

In the course of several tests published on our site, we have already had dealings with the Perfoline company, aka Ab Vital and Institut Nutritia.

We’ve already talked about this company on several occasions, warning consumers about the hidden clauses included in this type of company’s GTC. The company is known to anti-scam networks for its abusive direct debits, bogus free trial offers and so-called miracle products.

Konjac Forte ingredients

Konjac Forte’s main and unique ingredient is, of course, KONJAC.

Konjac is rich in glucomannan fibers, which are said to have a powerful appetite-suppressant action. These fibers act in the stomach by multiplying their original volume by 200. By swelling so much in the stomach, the feeling of satiety arrives more quickly, and the quantity of calories ingested is reduced.

But the benefits of konjac don’t stop there. This natural ingredient is also said to reduce cholesterol and glucose levels in the blood. Konjac is also said to be excellent for regulating metabolism, and reducing the effects of irritable bowel syndrome.

And here’s the konjac forte packaging label:

Scientific studies on Konjac Forte

No scientific studies have yet been carried out on Konjac Forte.

However, EFSA, in its review of konjac – the ingredient, gives the following verdict on the various slimming claims made for konjac:

  • A cause-and-effect relationship has been established between glucomannan consumption and body weight reduction, in the context of a restricted diet;
  • No cause-and-effect relationship has been established between glucomannan consumption and the reduction of post-prandial glycemic responses (2 hours after the meal);
  • No causal relationship could be established between glucomannan consumption and maintenance of normal blood glucose levels;
  • No causal relationship could be established between glucomannan consumption and the maintenance of normal triglyceride levels;
  • No causal relationship could be established between glucomannan consumption and the promotion of normal intestinal transit;
  • No causal relationship could be established between the consumption of glucomannan and the reduction of potentially pathogenic micro-organisms in the digestive tract.

Konjac saves the day by proving genuinely effective for weight loss. However, the other properties of this ingredient are invalidated by EFSA.

Another randomized, double-blind, placebo-controlled study conducted on 83 volunteers (66 women and 17 men), who were administered glucomannan for a period of 60 days, concluded that glucomannan is effective for weight loss, body fat reduction and cholesterol lowering. The study notably announces that these positive results are dependent on certain compliance corrections applied upstream.

(Source: Integrative Health Technologies, Inc, San Antonio, Texas (G.R.K.), Department of Pharmacy, University of Houston, Houston, Texas (D.B.), Department of Biochemistry, Georgetown University Medical Center, Washington, DC (H.G.P.). Kaats GR., Bagchi D., Preuss HG. J Am Coll Nutr. 2015 Oct 22: 1-7).

Comparing the results of these studies and adding those obtained in the various studies mentioned in our previous article on konjac, we are faced with contradictory conclusions. This observation leads us to believe that further studies should be carried out on konjac, to truly validate or invalidate its properties.

One thing is certain: konjac and glucomannan can have an effective effect on weight loss, but only under very specific conditions and within a well-defined lifestyle (diet + physical activity).

Konjac Forte side effects and contraindications

The manufacturer lists a number of precautions for use on its product label, including the risk of suffocation, a well-known feature of konjac and the subject of several alerts by official health authorities.

Konjac can also cause diarrhea and flatulence.

Finally, konjac’s supposed action on glucose could reduce blood sugar levels beyond what is healthy, in people already taking medication to reduce glucose or cholesterol levels.

Consumers’ opinion about Konjac Forte:

When we consulted consumer opinions on this product, we found ourselves faced with various statements: unpleasant smell, constipation problems, violent vomiting attacks, no appetite-suppressant effect, no feeling of satiety…The only good point on which the vast majority of consumers agree is its ease of use.

In short, the general trend in user testimonials is towards the negative, classifying this product as ineffective and with no apparent effect.

Konjac Forte price and guarantee

Konjac Forte is available in different packs:

  • Objectif – 5 kg – 15-day cure – €29.90
  • Objectif – 10 kg – 30-day cure – 49,90€ + 1 free detox foot pad kit
  • Objectif – 20 kg – 60-day treatment – 89.90€ + 1 free detox foot pad kit
  • Objectif + de 20 kg – 120 days of treatment – 149,90€ + 1 free detox foot pads kit

Delivery is free for packs over 20 kg. Otherwise, shipping costs €7.90.

The manufacturer offers a 90-day money-back guarantee.

Our opinion on Konjac Forte

To remain objective, Konjac Forte seems to meet the standards set by the official authorities in terms of its dosage and main ingredient.

What we find fault with are the maneuvers used by the manufacturer, which many people consider to be misleading, in particular the repeated sampling without the customer’s consent. The web is full of complaints published against this manufacturer.

Leave a Comment


  • Marie

    Glucomannan has a very bad effect on me after just one dose? Every time I’ve tested it (one dose before a meal), I’ve had a severe case of nausea a few hours later, and even vomiting on one occasion.
    and above all an intense stomach ache (spasms) with diahrea within 12 hours of taking it…

    So I’m really astonished that it’s still on the market and I wouldn’t recommend it at all because you feel really bad after taking glucomannan…. Weight loss, that’s for sure, considering the 12 hours spent sick in the bathroom! Every time I try it, I get sick, so be careful!

    • Marie

      And just for additional information to my comment, without quoting the brand of glucomannan that made me sick for clue it was Konjac powder by stick lemon taste (1 stick to take 30 min before the meal) …. Maybe it’s the dosage in this stick… I think it’s simply the negative effect of glucomannan, which disrupts intestinal transit and causes diahrea and bloating associated with painful spasms…. So really I strongly advise against it

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