Trying to Lose Weight?

Losing weight can be difficult, but at least in terms of calories it’s simple. If you burn more calories than you take in, you’ll lose weight. As a formula, it’s clear and concise. In the real world, it involves a whole lot of sweat and salads! It’s no wonder then that people look for less demanding ways to burn fat. Fat burners are supplements that claim to improve your body’s ability to shed weight. They’re usually meant as an adjunct to a healthy diet and exercise regime. But what do they contain, do they work and are they safe?

What Are Fat Burners?

Fat burners are supplements, and can be in tablet, capsule and liquid forms. They may also be called ‘fat metabolizers’. They claim to contain ingredients that help your body break down fat as a fuel source.

How do Fat Burners Work?

Depending on the manufacturer, fat burners can contain a range of ingredients that are claimed to help burn fat. Some fat burners focus on one ingredient while others advertise a combination. The ingredients present are meant to energize you for exercise, help your body shed fat during exercise and suppress appetite. Let’s examine some of the common ingredients present in fat burners.

Do Caffeine Fat Burners Work?

The very same chemical we find in our coffee and energy drinks! Caffeine increases epinephrine in the blood (also know as adrenaline). This hormone causes your body to start breaking down fat. This releases fatty acids into your bloodstream. In addition to breaking down fat, caffeine can speed up your resting metabolic rate. It also suppress appetite.

Caffeine is a well-researched chemical, but that doesn’t mean you shouldn’t watch your intake. If you’re taking caffeine-based fat burners you may want to drink less caffeinated drinks. The side effects of too much caffeine intake may include difficulty sleeping, increased heart rate, headaches and agitation.

A cup of coffee placed on top of a mound of coffee beans. Coffee contains caffeine, which can help exercise performance.

Do L-Carnitine Fat Burners Work?

L-Carnitine occurs naturally in the body. It’s a key part of the fat burning process, in which our mitochondria use our fat to generate energy. It can also be obtained from some dietary sources, like red meats and fish. So, what happens when you take it in supplement form?

The results are mixed. L-Carnitine didn’t promote weight loss in moderately obese women. In another study focusing on L-Carnitine’s effect on weight loss in adults, subjects who were supplemented with L-Carnitine lost significant weight. However, it had diminishing returns.

Do 5-HTP Fat Burners Work?

5-HTP, or 5-Hydroxytryptophan, is naturally found in the body. It’s an amino acid which converts to serotonin in the brain. So how does this help burn fat? In truth, it’s more useful as an appetite suppressant than an exercise drug. Taking it orally can decrease carbohydrate intake and studies examining the role between serotonin and appetite have identified 5-HTP as a key influence in feelings of fullness. It’s used in fat burner supplements to help prevent calorie intake through snacking but won’t necessarily increase the productivity of your exercise.

You should be careful about taking 5-HTP if you’re taking anti-depressants. This is because anti-depressants can also raise the levels of serotonin in your body. Taking two different medications that both raise serotonin levels could result in serotonin syndrome. This can be a very dangerous condition, so make sure you’re avoiding fat burners with 5-HTP if you’re taking anti-depressants.

Do Glucomannan Fat Burners Work?

Glucomannan is a dietary fibre and it’s found in the root of the Konjac plant, or elephant yam. Konjac has a long history as a herbal supplement in Southeast Asia and is also an ingredient in many Asian foods like Shirataki noodles and tofu. It’s used as an emulsifier in food. The key property of Glucomannan is that it’s exceptional at absorbing liquid. It’s this property that earns Glucomannan a spot in fat burner supplements. Like 5-HTP, it’s primarily included to suppress appetite. By sitting in your stomach, Glucomannan promotes a feeling of fullness that prevents over-eating. In a study testing the relationship between dietary fibres and weight loss, Glucomannan was found to induce weight reduction.  Taking a Glucomannan supplement before a meal with a drink can be an effective way of preventing over-eating. Just make sure you don’t overdo it – it’s a well-tolerated substance at the small suggested doses, but too much could contribute towards feeling bloated, flatulence and soft stools!

Do Green Tea Extract Fat Burners Work?

Fat burners make use of chemicals found in another common drink: Green tea. Often lauded as a health drink, green tea extracts may increase fat oxidation. Green tea extracts can also be marketed as health supplements, as green tea contains chlorogenic acids which have anti-oxidant and anti-inflammatory properties.

In general, the main reason green tea extracts are included in fat burners is because of their caffeine content as well as their ability to be marketed as a health benefit.

Two cups of green tea. Green tea extracts are a common ingredient in fat burners.

Do Fat Burners Work?

So, we’ve looked at the ingredients that many fat burners contain. Some of the ingredients, like caffeine, are well known to increase energy. Others such as 5-HTP and Glucomannan can help you feel full and thus lower your calorific intake. Ingredients that help raise adrenaline can also be productive alongside structured exercise.

Some of the effective ingredients found in fat burners can be obtained elsewhere in your life through your diet but having concentrated doses in supplement can be convenient. If you take fat burner supplements, make sure to look at the research behind the main ingredient. You can take it alongside your food at the recommended doses. Fat burners are most effective when taken as part of a healthy diet and alongside structured exercise. Do not expect them to help you drop pounds if you’re sitting around eating ice cream! While some fat burners have stronger evidence supporting them than others, there is still no conclusive evidence showing any of these over-the-counter products are effective as weight loss agents.

Are Fat Burners Safe?

The fat burner ingredients examined in this article are generally safe in controlled doses. Some of them, such as 5-HTP, should not be taken by people on anti-depressants. Caffeine based fat burners should be used carefully, particularly if you’re still intaking large amounts of caffeine through energy drinks or coffee.

Some ingredients used in fat burners can be actively dangerous. One of them is DNP, or 2,4-Dinitrophenol. It’s a chemical used in industry for a variety of purposes including as a pesticide and explosive. So, why would anyone use it as a fat burner? It’s because DNP prevents energy from being stored as fat in the body. This raises metabolism and body temperature dramatically, which can cause severe weight loss. It’s a highly toxic chemical that has caused multiple deaths. DNP can cause fever, vomiting, rapid and irregular heartbeat, flushed skin and and sweating. It can be difficult to reverse the effects of DNP poisoning and many people looking to lose weight by taking DNP have fallen seriously ill and even died. It’s illegal to sell DNP for human consumption, and you should never take DNP for any reason.

Some fat burner supplements contain a combination of ingredients. Large combinations of these ingredients may have unforeseen interactions or side effects. While many fat burner ingredients are well-researched individually, combining them into one tablet is not so well researched. This is why you should talk to your GP or pharmacist before taking any fat burner supplements. If you have any questions, sign up for our free Ask A Pharmacist service for answers to any health or prescription related concerns.

Is There Any Fat Reduction Medication?

While there is dubious research on the efficacy of many of the over-the-counter fat burners, there are prescription drugs available that are well proven to work. The most studied and widely used of these medications is called Orlistat (brand name Xenical). Orlistat is used in patients with obesity and commonly prescribed in the UK. This medication works by attaching to the enzymes in your digestive system that aid the process of breaking down fats from your food. Orlistat and Xenical then works to block the intake of about one-third of the fat in the food you eat. 

Read ‘Obesity: What You Need to Know’ to learn more about the facts behind weight loss.

If you have any questions, sign up for our free Ask A Pharmacist service for answers to any health or prescription related concerns!