Written by Garett Reid | NSCA, CSCS, CISSN, M.S.E.S.S
Fact checked by Andrew Lenau, ISSA CPT & Sports Nutritionist
FACT CHECKED
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Whether it's an actual meal, snacking too much throughout the day, or chowing down when you're emotional, the most common reason for gaining weight is simply overeating.
But what if you could take a pill that took away hunger? What if a pill existed that left you feeling full and satisfied between meals?
Taking it would keep you from overeating or wanting to rummage through the fridge, and you could stay within your desired caloric intake. Sounds good, right? But, does a pill like this really exist?
Keeping you full and eliminating hunger is exactly what glucomannan supplements claim to do. And if what it claims to do is true, it would mean that glucomannan could be one of the most effective weight loss supplements on the market.
Curious as to whether it really works? Let's take a look at research and real life experience to find out.
Table of Contents:
- What Is Glucomannan?
- What Does Glucomannan Do?
- Does Glucomannan Really Work For Weight Loss?
- Additional Glucomannan Benefits
- Best Glucomannan Supplements For Weight Loss
- What Real Users Say About Glucomannan For Weight Loss
- Glucomannan Dosing
- Who Should Take Glucomannan For Weight Loss?
- Potential Glucomannan Side Effects
- FAQs
What Is Glucomannan?
Let's start with the basics.
Glucomannan is a type of water-soluble dietary fiber found naturally in the wild. It's derived from the konjac plant, also known as elephant yam, making up about 40% of its dry weight. That's a ton.
In the past, it's been combined with foods such as tofu and Shirataki noodles (we'll get into these below) to add volume. Designated as E425-ii, it's commonly added to modern foods as an emulsifier and thickener.
What Does Glucomannan Do?
You may be thinking that you already get fiber from other foods, so what makes glucomannan supplements so amazing?
Well, the thing is that when glucomannan touches water, it draws it in and expands. In fact, it's the most viscous dietary fiber that we know of. If you were to take a glass of water and place just a bit of glucomannan inside, you would have a cup of gel.
Applying that to food makes for cuisine that is highly filling yet low in calories.
Take the shirataki noodle, for example. Known as the "zero-calorie" noodle (around 15 calories per serving), it contains 97% water and 3% glucomannan. When consumed, the glucomannan in these noodles expands in the stomach, making you feel full with barely any calories.
Because this fiber takes up gut real-estate, glucomannan can also slow down absorption rates of sugar and cholesterol. Not only is this feature useful for diabetics and those with high cholesterol, but a slower absorption rate improves satiety.
Does Glucomannan Really Work For Weight Loss?
Before we look at specific studies, glucomannan supplementation seems effective for weight loss.
Perhaps the largest study on taking glucomannan supplements and weight loss was done in 2005¹. When comparing three different glucomannan supplements with a placebo, they followed participants while on a calorie-restricted diet. They found that all three glucomannan products worked relatively the same, producing significantly more weight loss than just the placebo.
Modest weight loss was also seen in several other studies²⁻³.
In 2020, a large meta-analysis looked at six trials with 225 subjects. They concluded that a glucomannan supplement was well tolerated and effective at creating moderate weight loss⁴.
However, not all studies are positive. A study from 2013 researched glucomannan use in 53 participants⁵. While well tolerated, the participants did not experience more significant weight loss.
Overall, glucomannan combined with a meal plan for weight loss seems to have a positive effect on losing weight.
Additional Glucomannan Benefits
Quite impressively, weight loss isn't the only thing that glucomannan is good for. Here's a quick list of the other benefits of glucomannan:
- Reduce cholesterol
- Balance blood sugar levels
- Lower risk of heart disease
- Lower risk of type 2 diabetes
- Treat constipation
Best Glucomannan Supplements For Weight Loss
Interested in taking glucomannan to support your weight loss goals? It can be purchased as either a standalone product or combined with other weight-loss ingredients into a fat burner.
Here are two great options.
1) Hourglass Fit:
Another excellent option for a glucomannan fat burner is HourGlass Fit. It utilizes glucomannan as the primary ingredient and also contains other powerful fat-burning ingredients such as the thermogenic Capsimax and 5-HTP.
Buy Hourglass Fit and benefit from the 2 in 1 power. Packed with nutrients and ingredients to help you burn fat and reduce hunger...
If you want to learn more about this weight loss supplement, which suppresses your appetite and provides a thermogenic effect, head to our article: Hourglass Fit Review: Does It Really Work For Weight Loss?
2) NOW Glucomannan:
If you're looking for a stand-alone product, we recommend NOW Glucomannan. NOW is one of our favorite "no-frills" companies that delivers simple, high-quality products. This product currently has a 4.3 rating from 4,257 ratings.
Some titles of reviews include:
- Suppresses my appetite!
- Overall great supplement; no complaints whatsoever
- Makes OMAD a breeze (One meal a day)
Looking for more great options? Check out our article on the 7 Best Appetite Suppressants, which contains multiple products featuring glucomannan.
Glucomannan For Weight Loss: What Do Real Users Say?
Studies are one thing, but when it comes to the real effects of glucomannan, you need to look at real life. To do that, there's no better place than Reddit.
Many of the actual users report positive outcomes. Instead of hearing from us, we'll list some actual responses below.
"I just came here to add that since supplementing this in my daily routine (pill form), it's finally broken me through the most epic plateau I have ever encountered." (source)
"I get deep hunger around meals, and since using konjac dissolved into water/sugar-free diluted juice, I can eat a smaller portion and not feel a gnawing sense of hunger every day and still lose weight." (source)
With that in mind, we also want to touch on many of the complaints:
- Tastes or smells bad
- Gas
- "Backed up"
Keep in mind that many of these were referring to konjac food. In other words, bad taste or smell won't be an issue if you simply swallow a pill, but it might if you get glucomannan from food or opt for a glucomannan powder.
Overall, I should clarify that glucomannan is not a miracle pill. Unlike thermogenics, which may increase metabolism to burn more calories, you must use glucomannan strategically to curb your appetite.
Many of the negative reviews report feelings of fullness but no weight loss. Glucomannan makes you feel full, but it only works if you consume fewer calories. If you continue to eat on a full stomach, it's not going to work.
What's The Best Glucomannan Dose For Weight Loss?
As mentioned above, you don't need to take a lot of this stuff to get an awesome effect. Studies suggest taking 2-4 grams a day provides optimal results.
Further, this needs to be divided out before every meal⁶. Keep in mind that glucomannan works by creating a sense of fullness, so you should aim to take 1g three times a day or before every meal.
Who Should Take Glucomannan for Weight Loss?
Glucomannan can be used by overweight or obese adults who are looking for a non-stimulant fat-burning supplement.
It can also be used by those who just need help with weight management. It's a great supplement if you tend to overeat in triggering situations. For example, you could take glucomannan supplements before attending a special event to combat any food cravings that may arise.
Potential Glucomannan Side Effects
Even though glucomannan is generally considered safe, there are a few things to consider. Some potential side effects of glucomannan include:
- Bloating
- Bad Taste/Smell
- Flatulence
- Soft stools
- Diarrhea
In addition, glucomannan supplements can prevent the absorption of certain medications. Therefore, check with your doctor to see about any interactions. If you're unsure, separate your consumption medication and glucomannan by 3-4 hours.
We should also mention that some complaints tend to be the consumer's fault. For instance, some people report being "blocked up for weeks," but when you read their story, they were consuming way too much. Perhaps this was due to a labeling issue, but these concerns seem user-related rather than the actual supplement.
What Other Supplements Are Good For Weight Loss?
Glucomannan has the potential to be a great weight loss aid when used properly. It can be used alone or with other diet aides, but keep in mind that glucomannan works by filling you up to reduce calorie intake. The good thing is there are other ways to combat unwanted fat.
Caffeine and green tea are both very effective stimulants, with numerous studies showing they support weight loss through fat reduction⁷.
Other supplements that have generally favorable reviews are:
- 5-HTP
- Capsimax
- Cayenne Pepper Extract
Check out our article 8 Best Supplements For Fat Loss for even more great options!
FAQs
Let's take a look at some of the commonly asked questions about glucomannan and weight loss.
Is glucomannan FDA approved?
It has been considered "safe" by the FDA since 1994.⁸ In addition, it's been added to the US definition of dietary fiber, but it hasn't been approved as a dietary supplement to treat conditions.
How much weight can you lose on glucomannan?
Most people can effectively cut out 300 calories a day on average, equaling about 2-3 pounds a month.
Can glucomannan be taken long term?
You should use glucomannan for short-term periods of 3 months.
How much glucomannan should I take for weight loss?
1 gram before every meal.
Can you take glucomannan and not eat?
You can, but it won't do anything. Glucomannan will promote weight loss by preventing you from eating as much. If you're not eating, then glucomannan has no benefit for weight management. The only time this may be effective is if you are fasting and have issues with cravings.
Can you take glucomannan at night?
No. Taking glucomannan at night will provide no benefit, assuming you take it after your last meal.
Glucomannan To Lose Weight: Our Final Verdict
All in all, glucomannan looks like it's a unique and interesting weight loss supplement. We like that it's a natural compound and can be taken as is without any other ingredients.
Further, it's a non-stimulant, which is great for those who don't like the effect, and it can be taken at any time. While there is some negative feedback, I believe most of it could be solved by simply taking a purer supplement rather than eating the noodles.
All in all, glucomannan is not a miracle drug, but it can help you lose weight through a unique mechanism seen in few other methods. That said, I feel that glucomannan could be a useful tool either by itself or in combination with others.
But remember, to lose weight, no matter what you take, you're going to have to fix your nutrition and start an effective exercise regimen!
Looking for a supplement that effectively burns fat and supports your weight loss goals? Check out the 8 Best Fat Burners For Men and the 9 Best Fat Burners For Women.
References:
- Birketvedt, G. S., Shimshi, M., Erling, T., & Florholmen, J. (2005). Experiences with three different fiber supplements in weight reduction. Medical science monitor : international medical journal of experimental and clinical research, 11(1), PI5–PI8.
- Keithley, J., & Swanson, B. (2005). Glucomannan and obesity: a critical review. Alternative therapies in health and medicine, 11(6).
- Sood, N., Baker, W. L., & Coleman, C. I. (2008). Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis. The American Journal of clinical nutrition, 88(4). https://doi.org/10.1093/ajcn/88.4.1167
- Mohammadpour S, Amini MR, Shahinfar H, et al. Effects of glucomannan supplementation on weight loss in overweight and obese adults: A systematic review and meta-analysis of randomized controlled trials. Obesity Medicine. 2020;19:100276. doi:https://doi.org/10.1016/j.obmed.2020.100276
- Keithley JK, Swanson B, Mikolaitis SL, et al. Safety and Efficacy of Glucomannan for Weight Loss in Overweight and Moderately Obese Adults. Journal of Obesity. Published December 30, 2013. https://www.hindawi.com/journals/jobe/2013/610908/
- Keithley, J., & Swanson, B. (2005). Glucomannan and obesity: a critical review. Alternative therapies in health and medicine, 11(6).
- Tabrizi, R., Saneei, P., Lankarani, K. B., Akbari, M., Kolahdooz, F., Esmaillzadeh, A., Nadi-Ravandi, S., Mazoochi, M., & Asemi, Z. (2019). The effects of caffeine intake on weight loss: a systematic review and dose-response meta-analysis of randomized controlled trials. Critical reviews in food science and nutrition, 59(16). https://doi.org/10.1080/10408398.2018.1507996
- Behera, S. S., & Ray, R. C. (2016). Konjac glucomannan, a promising polysaccharide of Amorphophallus konjac K. Koch in health care. International journal of biological macromolecules, 92. https://doi.org/10.1016/j.ijbiomac.2016.07.098
Garett Reid
Author