Underground Fat Burner Supplement Reviews 2024 – Truth Disclosed Here

The Underground Fat Burner is the latest creation by Matt Marshall. This supplement promises to help you reduce your appetite and burn fat at the cellular level. My review exposes how these claims stand up to scrutiny.

Matt Marshall is no new to the fitness and weight loss industry. He’s already well known for his controversial “Underground Fat Loss Manual” (reviewed here) and “How To Build A Classic Physique” (reviewed here).

He has now come up with a new, all-natural supplement purported to restore your appetite to healthy levels and burn fat all along.

The motivation behind Matt’s new creation was the result of an unexpected weight gain under the current lock-down measures. The current coronavirus situation has only made worse a problem that was already there since the beginning of the industrial age.

The ready availability of rich, highly processed food has made it all too easy for regular people to access food anywhere and thus overeat, which is the leading cause of the current obesity and weight gain problems experienced by many.

As a result, countless diet plans, systems, and fads have popped up over the years, like:

Underground Fat Burner Review
  • Paleo diet
  • Low-fat diet
  • Ketogenic diet
  • Low-carb diet
  • Mediterranean diet
  • Weight Watchers
  • Intermittent fasting
  • Whole 30 diet
The list goes on and on, and each diet has its pros and cons. However, the creator points out that the real issue is not a kind of a particular diet vs. another because all diets share a common factor: calorie deficit.

Matt argues that there is just one way to force your body to burn its fat storage and lose weight: eating fewer calories than your body needs for functioning. As simple as that, you cannot bend the truth.

What all diets or workout plans try to achieve is a calorie deficit in a way or another (mostly calorie-counting), the reason being that we all tend to overeat, which is caused in turn by what Matt describes as ” runaway appetite,” or out-of-control appetite. Therefore we gain weight.

You may or may not agree with his definition, but the bottom line is that weight gain and obesity are not so much weight loss problems as they are appetite problems, he reasons.

I have to say that it makes sense, as two significant factors cause overeating:

Food everywhere; there is an oversupply of rich, highly processed foods readily available anywhere, from the refrigerator at home to an overabundance of produce at the local store, particularly in industrialized, wealthy countries.

Genetically modified foods, engineered to grow bigger and sweeter, further fueling our dependence on glucose-rich nutrients in ever more significant quantities. These foods short-circuit your appetite because they tend to have less fiber to make you feel full and skew your insulin sensitivity glucose levels, thus causing you to eat more than you should.

In the old days before the industrial advent, you couldn’t find food everywhere. Even when you did, foods were healthy, fiber-rich, and non-processed and did not interfere with your natural appetite response.

You are hungry, you eat, you feel full, and you stop eating.

Because of this, the Underground Fat Burner was formulated precisely to tackle weight loss from two fronts:

  1. Naturally reducing appetite to healthy levels thanks to fibersol, a nutrient responsible for kick-starting 2 key appetite-regulating hormones.
  2. Supporting fat burning on the cellular level, specifically in the mitochondria, where fatty acids can be burned for energy.

2023 UPDATE – The Underground Fat Burner Is Currently Offered With A Discount

Underground Fat Burner Reviews

What Is The Underground Fat Burner Supplement?

First, the Underground Fat Burner is not the usual pill or capsule you would typically expect for this type of supplement. Instead, it’s a water-soluble powder to be taken once per day. The creator suggests a 3-month trial for best results, but there are options for one or six months, depending on your starting point and the amount of excess fat to lose.

The powder format may or may not be of your liking, as it does not have the convenience of a capsule. But Matt reckons that powder trumps the capsule format hands-down and is, in fact, necessary because it allows to releases the active ingredients better and faster, as it would be impossible to get the same potency and benefits from a pill or capsule.

However, the excellent point is that you can mix the powder with water or your favorite juice (the creator suggests plain water), then the ingredients are immediately released into your bloodstream and absorbed.

This, in turn, begs a few questions regarding its safety and quality. The Underground Fat Burner seems to pass with ease because it’s formulated using only extracts from plants and is manufactured in the US in an FDA-approved facility under GMP standards.

All ingredients are non-GMO and void of chemicals or the typical additives found in many fat-burning supplements that may make you feel jittery and nervous.

Also, the Underground Fat Burner supplement has already been tested on the author and many personal customers successfully, as you can see from the original and unique testimonials.

However, while manufacturing standards, ingredients, and initial results are reassuring, this supplement has not been tested by a third-party, independent agent.

It also needs to accrue a more extensive clientele database for the product to be deemed entirely satisfactory.

How Does It Work?

Underground Fat Burner Weight Loss

The Underground Fat Burner was formulated from a selection of natural ingredients in powder format precisely because its creator thought that regular pills and capsules could do little for curbing appetite and losing weight while rattling about your empty stomach.

The company chose the ingredients mainly to reset your appetite hormones and make you burn energy at the cellular level, which means it’s not the ingredients in the mix in themselves that cause your appetite to diminish.

Instead, they act as agents between you and two hunger hormones responsible for your feeling of satiety. In essence, they stimulate these hormones and reset your appetite to an average level as a consequence.

As a result, you eat less and burn fat for energy instead, losing weight.

The formula allegedly kicks in after about 4 hours from your last meal, making you burn fat until the next meal and, since the fibersol component in the formula lowers your appetite, you can go on longer without eating while burning fat along the way. A two-way approach.

This is how it works essentially, but to understand how this happens exactly, you need to have a look at the active ingredients.

Underground Fat Burner Ingredients

Underground Fat Burner Ingredients

There are ten active ingredients in the Underground Fat Burner formula. Two are the main ingredients, one responsible for lowering your appetite and one for burning fat for energy at the cellular level.

The remaining eight ingredients add potency to the formula thanks to their metabolic and energy-boosting properties.

Fibersol (the main ingredient) – Fibersol is a soluble dietary fiber, also called digestion-resistant maltodextrin. It is known to support bowel movement and weight loss by improving peristalsis and reducing post-meal hunger.

Specifically, it affects the satiety hormones PYY (Peptide YY) and GLP-1 (Glucose-Like-Peptide-1).  These hormones are released inside your intestine and signal your brain that you are full sooner than when you don’t have enough of them.

Fibersol has been shown in a clinical study to make you feel full sooner and for longer than people who don’t use it. It is the most critical ingredient in the Underground Fat Burner supplement because it reduces your overrun appetite, causing you to lose weight.

L-Carnitine L-Tartrate – This is the second most important ingredient in the Underground Fat Burner formula. It works hand in hand with sorbitol to amplify the fat-burning capabilities of the supplement.

While sorbitol helps you burn your fat storage by reducing your appetite and calorie intake, the L-Carnitine L-Tartrate ingredient helps transport fatty acids into the cells’ mitochondria.

The mitochondria are the combustion engines of individual cells because they burn the fatty acids and turn them into energy, which means that whatever calories you eat, they are more readily used for energy than stored as fat.

There are several types of L-Carnitine, but the creator chose L-Carnitine L-Tartrate because it is more easily absorbed than the others.

L-Tyrosine – This is a non-essential amino acid known to help you conserve energy and control adrenaline levels. It has a proven positive effect on mood and well-being since it produces noradrenaline and dopamine, reducing stress. It also improves attention and alertness.

Chromax® (Chromium Picolinate) – This is a patented form of Chromium that has been proven to impact glucose metabolism and insulin function, very useful to reduce hunger and cravings and deliver steady energy levels without spiky ups and downs.

Therefore, it affects body composition since it helps reduce fat tissue in favor of lean muscle, so athletes use Chromax.

Garcinia Cambogia Extract – Garcinia gummi-gutta is a trendy fruit because of its weight loss benefits. Its peel contains high levels of hydroxy citric acid, which blocks an enzyme called citrate lyase responsible for making fat.

It also makes you feel full sooner during a meal because it raises serotonin levels, which reduces appetite.

Caffeine Anhydrous – This type of caffeine is extracted from the seeds and peels of coffee plants rather than the bean. As the name implies, this form of caffeine is obtained through a dehydration process, which filters out all the water.

As a result, caffeine anhydrous is more concentrated and potent than regular caffeine. This is why combat forces use it to increase mental sharpness and improve performance in stressful situations.  But as far as weight loss is concerned, caffeine anhydrous helps burn fat thanks to a process called lipolysis, the breakdown of fat within the fat cells.

Forskolin Root Extract – Forskolin is a plant of the mint family and is well known as a weight-loss supplement that works by increasing lipolysis, a bit like caffeine does.

Forskolin helps create two enzymes, called lipase and adenylate cyclase, which release free fatty acids from the cells that can be burned as energy, thus helping reduce fat storage while preserving lean muscle.

CaloriBurn Grains of Paradise™ – CaloriBurn is a patented ingredient extracted from Grains of Paradise of the ginger family, a spice used in many dishes to add a bit of zest.

CaloriBurn activates the brown fat or BAT (Brown Adipose Tissue), which helps free up extra fat to burn it off. In other words, it turns white fat into brown fat, which regulates metabolism and energy expenditure.

Capsimax™ (Cayenne Pepper Fruit Extract) is a concentrated form of capsicum extract from the “red hot chili peppers.” It is made from the capsaicinoids contained in the peppers and supports metabolism and thermogenesis, the process of heat production that aids weight loss.

Capsimax™also turns fat into energy, decreases appetite, and increases energy expenditure while resting.

Bioperine® (Black Pepper Extract) – This ingredient offers multiple benefits. It improves metabolism by raising thermogenesis, thus aiding weight loss. Still, it also helps nutrient absorption so that all the ingredients contained in the Undeground Fat Burner supplement are utilized by your body and do not end up wasted in your urine.

Underground Fat Burner Benefits

Underground Fat Burner

This supplement looks very well set to gain popularity because of the balanced formula and quality of manufacturing. It offers multiple benefits, one being a powder supplement that is more easily absorbed than a pill or capsule.

However, as far as weight loss is concerned, these are the main benefits that the Underground Fat Burner offers:

  • It naturally curbs your appetite, actually restoring it to healthy, normal levels. You may not even be aware that the primary reason for gaining weight is the unhealthy super-appetite induced by the ready availability of calorie-rich foods and their highly processed manufacturing standards.
  • Not only does it help burn fat by forcing your body to burn calories from your fat storage, but it also makes the process more efficient by supporting fat-burning within your body cells.
  • It positively impacts energy levels because its ingredients also help regulate glucose metabolism and turn food into energy rather than fat.
  • As a consequence of the above point, it supports mental clarity and a positive, steady mood unaffected by fluctuating sugar and energy levels.
  • It helps restore your body composition, reducing adipose tissue and preserving lean muscle.

What Makes The Underground Fat Burner Different?

Aside from the quality of the ingredients and manufacturing standards, the Underground Fat Burner uses a generous dosage of all active ingredients. That’s also one of the reasons it’s produced in powder format and not in a capsule. You just couldn’t fit all the ingredients in the correct quantity into a single pill.

The other reason is that your body quickly absorbs the water-soluble powder. For a detailed review of the quantity of the ingredients in a single dosage, scroll back up.

How Fast Does It Work?

There is no quick and easy answer for that. This may depend on several factors like starting point, amount of fat to burn, personal response, etc.

The creator reckons that a 3-month supply is a good middle ground that works well for most people, while others may need one month or six months – he offers three different packages to suit all needs and pockets.

It’s worth noticing that the more jars you order, the cheaper the jar per unit. However, if you need just one jar (for one month), the option is there.

How To Take The Underground Fat Burner

If you are used to pills or capsules, this may come as a novelty.  You don’t pop anything in your mouth and swallow it with a glass of water. Instead, you have actually to prepare it, but it takes just a few seconds.

Matt Marshall recommends taking one scoop of Underground Fat Burner from the jar and drop it into an 8oz glass of water, then stir it and drink it. This should be done first thing in the morning every day, once per day.

However, the creator allows for some flexibility and reckons you may use a second dose in the afternoon if needed, but no more than that and not within 3/4 hours before bedtime anyway.

Underground Fat Burner Side Effects

A crucial question. Is this supplement safe? All the ingredients are completely natural, and the formula is manufactured in the US in a state-of-the-art, FDA-approved facility under GMP (good manufacturing practice) criteria.

No adverse side effects have been reported on all the customers who used it. However, you should always use your common sense and ask for your doctor advice if you:

  • Know to suffer from any condition.
  • Have high blood pressure, or heart, kidney, thyroid disease.
  • Suffer from a psychiatric condition or depression, seizures, anxiety, or stroke.
  • You are pregnant (or breastfeeding).
  • You think you may be allergic to any of the ingredients.
  • You are under the age of 18.

Where Is The Underground Fat Burner Made?

Again, this supplement is processed in and distributed from the USA. It is made in a modern facility approved by the FDA and manufactured under GMP standards.

All the ingredients are tested for purity before being processed, and the supplement undergoes a yearly audit to maintain its GMP certification.

Can You Buy It In Stores – Amazon  – Walmart – GNC?

No. You can only purchase the Underground Fat Burner through the official website @ https://undergroundnutritionco.com/

Underground Fat Burner Price Shipping And Guarantee

Matt Marshall offers this supplement with a bulk-saving arrangement – the more you order, the cheaper the individual unit. Specifically, the Underground Fat Burner is available in 3 packages.


  • 1 jar (30-day supply): $49.95 + paid shipping.
  • 3 jars (90-day supply): $119.95 ($39.95 per jar) + paid shipping.
  • 6 jars (180-day supply): $198.00 ($33.00 per jar) + FREE shipping.

Underground Fat Burner Reviews


The product is delivered through USPS to the USA and Canada, and delivery times vary from 3 to 5 days depending on the distance. Orders placed on the weekend will be processed the following Monday.

Under normal circumstances, this supplement should be shipped internationally to any country (5 to 14 days for delivery). Unfortunately, due to the COVID-19 pandemic, distribution is temporarily limited to the US and Canada.

Let’s hope this situation can change soon, and not just for the supplement.


There is a 60-day money-back guarantee in place to safeguard your consumer’s rights. Should anything be not satisfactory, you are covered. The manufacturer is transparent, with contact details at the bottom of the Underground Fat Burner website and a dedicated, commission-free support team.

==>>Visit The Underground Fat Burner Official Website<<==

Underground Fat Burner Pros And Cons

Here is a quick recap of what I liked and disliked:


  • An unusual, natural supplement is water-soluble powder format for extra dosage and more effectiveness.
  • It is made from natural plant extracts, hence free of chemicals or preservatives.
  • It helps reduce out-of-control appetite (the primary cause of weight gain) and moderates hunger.
  • It promotes fat burning at the cellular level and the production of energy.
  • It improves metabolism and optimizes blood sugar levels.
  • It improves mood and sharpens mental focus.
  • It restores a healthy body composition – less fat on lean muscle mass.
  • Generally very safe, unless you have a specific condition, no side effects reported.
  • It is made in the US in a controlled environment under strict guidelines.
  • 60-day money-back guarantee


  • Not available in stores or through different channels other than the official website.
  • Only available in the US and Canada as of now. Temporarily unavailable in the rest of the world due to the pandemic restrictions. This may change later, hopefully.

Verdict – Is The Underground Fat Burner Any Good?

Overall, the Underground Fat Burner is a quality weight loss supplement that targets an often-overlooked factor in any diet plan or nutritional program: appetite. Or better, unnatural and overstimulated appetite from modern-day, highly processed foods and their ready availability.

Since calorie-in vs. calorie-out is the central tenet that ultimately regulates your body weight and composition, it stands to reason that if you reset your appetite to normal levels, then you are on the way to reduce your body fat.

The Underground Fat Burner was formulated to do just that with the help of natural ingredients that help you restore your feeling of fullness and satiety while also helping you burn fat for energy.

Add to this that the ingredients also improve glucose metabolism and optimize blood sugar levels, then you also have the added benefit of constant energy levels and mental clarity.

If you are tired of pills and capsules that offer an inadequate response to your weight loss journey, the Underground Fat Burner could be the right solution.

Underground Fat Burner


Is Underground Fat Burner Safe To Use?

This supplement is 100% natural and produced in a controlled environment. It has already been used by many with no side effects. However, you should use your caution and consult a doctor if you have a condition.

Is It Legit?

The Underground Fat Burner is legit. It is manufactured in the US in FDA-approved facilities under GMP criteria, and its creator is a real person.

How Fast Can I Get Results?

The manufacturer recommends two or three months of usage as a reasonable average time frame to see substantial results, but you may need just one month or maybe six months, depending on many factors. Different packages are available.

How Do I Take Underground Fat Burner?

This is a powder supplement to be taken mixed with a glass of water every day in the morning. The water-soluble powder allows for better absorption of its nutrients.

Can I Buy It In Stores Or On Amazon?

No, You can purchase the Underground Fat Burner only on the official website, not anywhere else.

Where Is It Shipped In The World?

Unfortunately, it can be shipped just within the USA and Canada through USPS because of the pandemic restrictions. Hopefully, things may change later.

How Many Jars Should I Order?

There are three packages available, one jar, three jars, or six jars. However, how many you need depends on your situation. The larger the order, the cheaper the individual jar.

How Long For Delivery?

You can expect 3 to 5 working days for the US and Canada, depending on the distance. For the rest of the world, it usually takes 5 to 15 days, but at the moment, this option is not on the cards because of the pandemic.

Is It A One-Off Payment Or Not?

Absolutely yes. You only pay once, and that’s the end of it. There are no recurring charges or hidden fees.

Does Underground Fat Burner Offer A Guarantee?

Yes, the Underground Fat Burner comes with a 60-day money-back guarantee.

Underground Fat Burner


Average rating 4.6 / 5. Vote count: 22