The Truth About Fat Burner Supplements

Fat burners are one of the most popular supplements in the supplement industry. And for good reason, many people want to lose fat as fast as possible.

Consequently, many take these supplements without even understanding the contents of the tablets. Here's the truth about fat burners.

What Is A Fat Burner?

Fat burners are usually manufactured in tablet form and are marketed as miracle pills that will strip all of the fat off of your body in a week. These tablets target specific components of fat loss. Often by boosting metabolism and energy, curbing appetite and promote lipolysis.

Side Effects

Fat Burners are commonly associated with having dangerous side effects, common reactions to fat burners include:

• Diarrhoea

• Constipation

• Intense Abdominal Pain

• Nausea

• Insomnia

• Headache

• High Blood Pressure

Rare side effects include:

• Liver Damage (Hepatotoxicity)

• Heart Failure

• Heart Attack

Ingredients In Fat Burners


Caffeine is the most widely consumed psychoactive drug in the world today. Often ingested by drinks like tea, coffee, energy drinks and fizzy drinks.

The stimulant is well known for its ability to block a neurotransmitter called adenosine. By blocking adenosine it increases the release of dopamine and norepinephrine. This process causes elation and increases energy and alertness. It may also improve athletic performance by 12%.

Caffeine accelerates fat loss by stimulating the nervous system, signaling it to release the energy held in fat stores by raising adrenaline levels in the blood.

The study also showed the RMR (Resting Metabolic Rate) also increased up to 11%. This is dose dependant however, as higher doses will have a greater impact on RMR.

Side Effects

Overdosing or over consuming caffeine can do more harm than good. Using caffeine too often can lead to dependency and your body can build tolerance to the drug, so you have to take more to get the same effect. Other side effects include:

• Restlessness

• Insomnia

• Headaches

• Nausea

• Rapid or abnormal heart rate

• Dehydration

• Anxiety

• Dependency


If used in moderation, caffeine can be a very effective tool to lose fat. But a calorie deficit is still needed to lose fat. I recommend getting your caffeine from natural sources like coffee green tea, black tea and matcha tea.

Fat burners abuse this stimulant however, often including as much as 500mg caffeine per tablet, which if taken daily will very quickly lead to dangerous side effects and will also reduce the effectiveness of caffeine overall as your body builds a tolerance to it.


L-carnitine is a naturally occurring essential amino acid that plays a vital role in fatty acid transportation into your mitochondria cells. Mitochondria uses these fatty acids to produce energy for the body to use. (1)

The body can produce L-carnitine by itself by synthesizing it endogenously from two amino acids, Lysine and Methionine. This process occurs in the kidney, liver and brain. L-carnitine can also be consumed in small amounts by eating meat or fish. Vegans and other people with genetic issues may be unable to produce enough of this nutrient. Therefore supplement may be necessary. (2)

L-carnitine is essential in preventing and fighting disease, through its mitochondrial function boosting properties. There is promising evidence that L-carnitine can be clinically applied to help people with diabetes, by improving nerve conduction, neuropathic and immune function in people with diabetes. Furthermore, it also holds promise in helping a variety of neural disorders like Alzheimer's.

As a nutritional supplement there is evidence carnitine may help cardiovascular disease as well as treating obesity, improving glucose intolerance and boosting metabolism. A study on rats found that the rats receiving carnatine supplements promote muscle recovery and athletic performance.

This is good news, but does it aid in fat loss? A study on 38 women who exercised 4 times per week showed no difference in weight loss for those who took L-carnitine and those who did not take it.

But that does not mean it doesn't work at all, another study found that obese and older individuals lost an average of 1.3kg more while supplementing L-carnitine.

Side Effects

• Diarrhoea

• Headaches

• Insomnia

• High Blood Pressure

• Low Blood Sugar & High Triglycerides (in people with diabetes)

Avoid carnitine if you are allergic or sensitive to it. Children and pregnant women should also not use carnitine as its safety for these individuals are unknown. Check with your doctor before taking L-carnitine as it may have adverse effects with other drugs or medication.


L-carnitine is promising for clinical use in people with neuropathic disorders, obese individuals and diabetes. However the effectiveness of L-carnitine in weight loss or fat loss is only noticeable in people who are obese, diabetic or older adults. Even then, L-carnitine will only aid in fat loss if there is an appropriate diet in place for fat loss to result.

Green Tea Extract

Green tea is known as one of the healthiest beverages in the world, packed with antioxidants called catechins. A study conducted on the beneficial effects of green tea suggest that it may benefit a wide variety of ailments such as, cancer, heart disease and liver disease. These are reported to be because of the high content of catechins, specifically Epigallocatechin-3-gallate. Furthermore, there is evidence that green tea could also be beneficial to obese individuals, type II diabetes and cardiovascular disease.

Green tea has been linked to the prevention of many other types of cancer, including: lung, colon, esophagus, mouth, stomach, small intestine, kidney, pancreas and mammary glands. (3)

What's the difference between Green Tea & Green Tea Extract?

Green tea leaves are most often used in tea bags to infuse the green tea into water to be drank. This is the best way to consume green tea, however some opt for capsules of green tea extract if they cannot come to terms with the taste. Beware, not all extracts are manufactured the same and may not be green teas pure form. The extraction process can also miss some of the content found in the leaves only.

High doses found in some green tea extract capsules may pose risks to health. Overall, we recommend not taking green tea extract.

Can Green Tea Aid Fat Loss?

Green Tea contains caffeine, although in small amounts (up to 40mg per cup) it is still potent enough to have some effect. Caffeine, as we know is a great fat burning stimulant, however green tea does not contain enough to make it the main fat burning property.

But, the most plentiful antioxidant in green tea, Epigallocatechin-3-gallate (EGCG) can help promote the production of a fat burning hormone called norepinephrine. Interestingly, caffeine and EGCG may have a synergistic effect, further boosting fat burning properties.

Almost every fat burner contains green tea extract because it has been repeatedly proven that it does in fact increase fat burning, even more so during exercise.

A study on men who took green tea extract prior to exercise burned on average 17% more fat than the men who did not take the supplement. Another study showed that green tea extract can increase resting metabolic rate by up to 8%.

In one study on 60 obese individuals, those supplemented with green tea extract lost 3.3kg more weight after 3 months than those not taking the supplement. However the effect green tea has on the metabolism may vary from person to person.

Side Effects

In one rare case a 17 year old woman taking green tea extract as a fat burning supplement suffered liver and kidney damage after taking the supplement. Because of the extreme amount of catechins in green tea extract capsules plus taking them multiple times a day, every day, it can be extremely dangerous. For reference, one cup of green tea contains 50 to 150mg of catechins, whereas tablets sometimes contain more than 700mg of catechins. This dosage can cause acute liver damage.

• Upset Stomach

• Constipation

• Liver Damage (In extreme doses)

• Kidney Damage (In extreme doses)


Green tea is the best beverage to drink for overall health and can definitely aid in fat loss, but again it will need an appropriate diet in place for fat loss to occur. Green tea extract can often do more harm than good when it comes to fat loss. It is much safer to steer clear of green tea extracts.

Bottom line, green tea extract can help with fat loss but the results will vary between individuals. If you are going to use green tea extract be sure to check the concentration of the extract on the label, and use them in moderation.

So, Do Fat Burners Really Work?

The question if fat burners really work is extremely controversial and varies between individuals. Some ingredients in fat burners are beneficial to fat loss but are only modestly effective and will not burn fat on their own. These supplements should only be used as just that, a 'supplement'. Everybody reacts differently to these compounds and everyone will have different results.

Some fat burners may work, but often they are misused and will not have any results at all. They can accelerate fat loss if taken with a calorie deficit and high protein diet. But I do not recommend them nonetheless.

A guaranteed way of losing fat however, is a personalised diet plan. A good diet is the centerpiece of fat loss and no legal fat burner can change that. The risks that fat burners pose outweigh their benefits 10-to-1.

Often, manufacturers market their fat burners as the ultimate fat burning pill, and consumers believe it. Because fat loss can be stressful and requires patience, many people invest into these pills only to be dissapointed. I, myself have experienced this and was extremely disappointed. I did not understand any of the compounds in the fat burner tablets, and that's where it can be dangerous. High doses of compounds can have adverse effects on individuals and may even be deadly.

If you are going to use fat burners, visit your doctor to ensure you are eligible to take them.

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