Best Rated Diet Pills Free Trial Scams


Fenburn is a metabolism boosting weight loss supplement with a very high caffeine content. Caffeine has been proven successful as a weight loss supplement, but it also comes with many potential health risks and side effects.


Fenburn Pros
  • One of the ket ingredients, caffeine has been proven effective in clinical trials
Fenburn Cons
  • Not all ingredients have been proven effective in clinical trials
  • Many potential health risks and side effects associated with high caffeine intake
  • Spelling mistakes on the company’s website damage credibility

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Fenburn Review

Produced by Ltd, Fenburn is a weight loss supplement that works primarily as a metabolism booster, increasing the body’s energy expenditure particularly during periods of intense workout. The product contains many ingredients associated with weight loss, primarily caffeine which has been proven to be successful in increasing energy expenditure in clinical trials. However, not all of Fenburn’s other ingredients have been proven quite as successful, and because of the high level of caffeine the product comes with an extensive health warning and a long list of potential side effects, including nausea, headaches and in extreme cases, a risk of heart disease or stroke.

Fenburn Claimed weight loss benefits Ltd claims that Fenburn helps the body lose weight through the process of thermogenesis, wherein the body is able to break down fats at a faster rate. According to the company, Fenburn helps to keep the body’s metabolic rate high throughout the day, which enables the body to burn more fat even when at rest. The company’s website also claims that Fenburn is an effective anti-oxidant thanks to its green tea content, and that it contains appetite suppressant qualities, although it is unclear as to why as none of the named ingredients have be proven to have any consistent effect on appetite.

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How Fenburn Works

Fenburn’s primary benefit as a weight loss supplement come from its metabolism boosting properties – these are provided primarily thanks to the large dose of caffeine that is included within each tablet, but could also be due in part to the inclusion of ingredients like green tea extract, capsaicin and bioperine. These ingredients are believed to increase the body’s natural energy expenditure after consumption, helping the body to burn more calories in a shorter amount of time and thus helping the user to lose weight. As the body’s energy expenditure increases, it burns excess energy that is stored as fat, and the body becomes leaner and lighter as a result.

Caffeine is well known for its stimulant qualities, and these are the primary reason it is used in so many weight loss supplement. Caffeine consumption triggers increased energy consumption within the body, which is why its users experience an energetic buzz. This increase in energy expenditure burns through calories at a faster than normal rate, which leads to the body burning through its built in fat reserves. The energy buzz also helps users to get the most out of a workout session, as they are able to push themselves further and for longer. Caffeine is also a natural diuretic, which can also be useful in losing some weight.

Green Tea Extract
Green tea’s primary weight loss benefit is believed to be because it naturally contains caffeine, and as such drinking green tea helps to increase energy expenditure. Green tea is also a natural antioxidant, which while not necessarily having a large direct result on weight loss, does help the body to recover from the negative effects caused by obesity, and as such green tea’s antioxidant nature indirectly helps with the process of improving health and maintaining a healthy weight.

Oolong Tea
Oolong tea extract works in exactly the same way as green tea, providing a boost in energy expenditure due to the caffeine inherently contained in the substance and thereby aiding the process of burning fat. Oolong tea is also an antioxidant, which is beneficial as it helps the body recover from the adverse effects of symptoms of obesity.

Bitter Orange Peel
Bitter orange peel is a regular inclusion in some riskier diet pills because it is structurally very similar to ephedra, a powerful diet supplement that was banned by the US Food and Drug Administration over concerns regarding its potent side effects. Bitter orange is believed to contain chemicals that raise the heart rate and blood pressure – as more blood pumps faster around the body, the body has to burn more calories to keep things running smoothly. This in turn burns off fat.

Found naturally in capsicum (also called peppers), capsaicin is present in all types of peppers except bell peppers and is responsible for the spicy taste users experience when eating peppers of almost all kinds. This reaction triggers an increase in energy expenditure within the body as the user experiences a rise in body temperature, and this burns through fat at an increased rate for a time. As the body reacts to the spice of capsaicin, the user benefits from increased energy expenditure while feeling these effects.

The logic behind including L-Tyrosine in weight loss supplements comes from its purported mood enhancement properties – it is believed by some that as L-Tyrosine is used in the body to create dopamine which is responsible for mood control in the brain, taking L-Tyrosine supplements will help the body to create more dopamine, and therefore the person will be happier. Many diet pills include it in an attempt to help users maintain a positive attitude throughout workout and to burn more energy, and some claim that L-Tyrosine is also effective at increasing energy expenditure, although none of these effects have been proven in a clinical trial setting.

Commonly found in black pepper, much as capsaicin provides red peppers with their spicy taste, bioperine similarly gives black peppercorn its own powerful taste. Those who consume black pepper feel the effects of the taste by experiencing an increase in body temperature and sometimes in sweating, dependent on the dose. This increase in energy expenditure takes up calories, and encourages the body to burn through its natural fat reserves, particularly when the consumption of bioperine is combined with strenuous aerobic exercise.

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Key Ingredients

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Fenburn contains a lot of different ingredients that are relatively common in modern diet pills. These ingredients come from a range of sources and have varying success as a dietary supplement, but also with varying potential side effects, ranging from ingredients that are common in everyday foods and are relatively harmless, through to powerful stimulants that are particularly dangerous when taken in extreme doses.

The most popular stimulant in the world, caffeine is included in varying doses in many everyday foodstuffs including coffee, tea, chocolate, cola and energy drinks. Caffeine occurs naturally in many plants and is well known for its special energy boosting abilities, giving users an increased buzz. However, caffeine is highly addictive and overuse can lead to some unpleasant side effects, including dizziness, nausea and in extreme cases, heart murmurs, high blood pressure and brittle bone diseases. Withdrawal effects for those who are addicted are also not pleasant, and as such doctors advise that patients limit their caffeine use and do not overindulge regularly.

Green Tea Extract
Used in herbal medicine for thousands of years, green tea is exceptionally popular throughout the Eastern world and is believed to have many healing qualities. Brewed from the leaves of the camellia sinensis tree, green tea is used to treat illnesses and ailments including high blood pressure, depression and headaches, and is also believed by many to have preventative qualities, helping to keep diseases like cancer and Alzheimer’s at bay. Despite its reputation as a soothing and calming drink, green tea contains a moderate dosage of caffeine, which is thought to be its primary benefit as a weight loss supplement.

Oolong Tea
Oolong tea is almost exactly the same as green tea, as both come from brewing the camellia sinensis leaves and the only difference is that green tea is made by brewing dried leaves, while oolong leaves are left to wilt and ferment slightly before brewing. Much like green tea, oolong tea is believed to help treat a variety of ailments, including issues of brain function such as dementia and Alzheimer’s, thanks to its antioxidant nature. As with green tea, oolong tea contains some caffeine and can be harmful when drank in excessive amounts of more than five cups a day.

Bitter Orange Peel
Bitter orange trees are native to east Africa and tropical Asia. The oil of the bitter orange is used in a variety of products including foods, cosmetics and aromatherapy oils. It is also used in traditional Chinese medicine as a cure for heartburn, indigestion, congestion, and for weight loss. Bitter orange peel is a contested ingredient in diet pills as it closely resembles ephedra, a powerful but dangerous weight loss substance that has been banned by the US Food and Drug Administration. There has not yet been sufficient study to determine whether bitter orange peel is similarly harmful.

Capsaicin is most commonly found in capsicum (another name for peppers), and is present in all varieties of peppers except the bell pepper. Capsaicin is what gives peppers their spicy taste, and it is present in traditional meals from all over the world. As well as being used as a metabolism booster, capsaicin is used in some circles as a topical painkiller – it is often added to creams that are designed to alleviate itching, swelling and discomfort of the skin. While its effectiveness both as a painkiller and as a weight loss aid are debatable based on clinical trials, capsaicin is almost entirely free from side effects for most people.

L-Tyrosine is an amino acid that occurs in most proteins and can be found in abundance in fish eggs and meat. It is used in the body to make neurotransmitters that send signals in the brain, including dopamine with is responsible for mood control. A lack of dopamine in the brain can cause depression, and so L-Tyrosine is linked to the production of good moods, and it is also thought to be beneficial in helping people combat stress and sleep deprivation.

Bioperine (also known as piperine) is another name given to common black pepper extract. Black pepper is widely eaten throughout the world and is added to a variety of dishes to give added flavour. Bioperine is what gives black pepper its taste, and it is believed by some to have additional benefits to the human body. A study into the effects of black pepper extract in rats concluded that the substance may have many benefits, including use in combatting arthritis and depression. Much like capsaicin, the only side effects associated with bioperine are its powerful taste, but this is enjoyed by billions of people around the world.

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Clinical Studies

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Fenburn itself has not been the subject of a clinical trial, but all of its active ingredients have at some point been subjected to studies to determine their effectiveness as weight loss substances. While individual user’s experiences can be helpful in assessing a substance’s effectiveness, a proper clinical trial is conducted in a controlled environment where scientists use rigorous tests to determine whether a substance is actually effective or not. These tests are designed to eliminate bias as far as it is possible, and are only considered successful if the results can be reproduced.

Caffeine has been the subject of many clinical studies to determine its effect on weight loss. One such study in 1989 measured the effects of caffeine on the human body’s resting energy expenditure over a 150 minute period after the drug was taken. Two groups of participants were either given caffeine or a placebo, so that scientists could compare the effects of caffeine against the normal body in the same conditions, and the amount of energy the participants burned in the next two and a half hours was measured. The results showed that participants who had been given caffeine on average burned 8-11% more energy than the participants who had been given a placebo. The study concluded that caffeine consumption has a dramatic effect on the amount of energy burned after taking the drug.

Green Tea Extract
A study conducted in 2007 into the weight loss potential of green tea studied sixty participants, all of Thai origin, to determine the influence green tea has on weight loss. The participants were divided into two groups, both of which were fed a diet of traditional Thai food, with one group receiving green tea. This experiment was undertaken over the course of twelve weeks, during which the participants were carefully monitored. The study found that there was a slight increase in weight loss and energy expenditure for the group who had received green tea, but that there was no different between the groups’ levels of hunger, food intake or exercise. The study ultimately concluded that green tea does aid weight loss when combined with a traditional Thai diet.

Oolong Tea
A study in 1999 analysed the weight loss properties of oolong tea when administered to mice. The mice were fed a high fat diet over the course of ten weeks while also receiving oolong tea supplements. The mice were analysed and compared to a control group that received the same diet but not the oolong tea supplements. At the end of the experiment it was found that the mice who had received oolong tea were less likely to have developed the negative effects related to obesity including fatty liver. The study concluded that oolong tea did have an effect in preventing obesity, and it was concluded that this was due at least in part to the quantity of caffeine present in the tea.

Bitter Orange Peel
There is not a lot of clinical evidence to support any claims that bitter orange peel is effective as a weight loss supplement. One review in 2004 attempted to collate data from previous studies to form a consensus regarding bitter orange, but was only able to find one study to look at. The study had a very small sample of 20 participants and a small measuring period of 6 week, but over that time did not find any evidence to support orange peel as a weight loss aid.

A 2009 study looked into the effectiveness of capsaicin as a weight loss substance by measuring the effects of capsicum on energy expenditure. 20 participants were given capsicum supplements while an additional 20 were given placebos to provide a control group. The participants were regularly weighed an monitored as part of the experiment, to determine how much energy they burned after taking the supplements. The study concluded that there was no noticeable difference between the two group’s energy expenditure, but that there was a slight, ‘nearly significant’ improvement in the capsicum group’s weight loss. The study therefore concluded that there may be slight benefits to capsaicin as a weight loss substance, but these effects are not due to energy expenditure.

There have not been any studies into L-Tyrosine that prove that it is an effective weight loss aid. One study in 2013 attempted to examine its affects on obese particpants who were given a strict weight loss programme. In a randomised test of seventy participants, half were given L-Tyrosine supplements while half were given placebos. Only 45 participants continued with the exercise programme, and of those who did, no distinct differences were seen between the two groups. The trial concluded that more study is required to determine for definite whether L-Tyrosine has any benefit as a weight loss supplement.

While there have not been many studies into the effects of black pepper extract on human weight loss, one prominent study in 2011 looked at its effects when administered to obese rats. The rats were given black pepper extract in various doses over a period of three weeks alongside a high fat diet which caused them to gain weight. The study found that the rats that received the highest doses of black pepper extract suffered fewer of the effects of obesity – they had lower body weight, fat mass and cholesterol. The study also found that those rats that had been given low doses of black pepper, when later given larger doses instead, experienced a reversal of the initial effects of obesity without a change in diet. The study therefore concluded that piperine supplements do have benefits to rats. Further testing on humans is required before it can be proven that the results are generalizable.

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Weight Loss Power: 65/100

Fenburn contains large amounts of caffeine, which has been clinically proven to increase energy expenditure and thereby aid increased fat burning and weight loss. While not all ingredients within Fenburn have been proven effective, the caffeine within it alone is enough to help the user increase their workout potential and burn large amounts of calories.
Speed of results: 60/100

Users should feel the initial effects of Fenburn from their first dose – this is mainly due to the energy buzz produced by consuming a large quantity of caffeine. In subsequent days and weeks as users continue to use the product they should see results quickly, in relation to the amount of exercise they perform and the care they take to eat healthily.
Appetite Suppression: 30/100 claim that Fenburn contains high levels of appetite suppressants, however none of its ingredients have been proven in clinical trials to display these qualities. That said, one possible side effect of the caffeine high within the body and the resultant increase in energy the user experiences may help the user to go longer without needing to eat, however this will depend on the amount of exercise the user undertakes, as taking Fenburn will naturally increase energy expenditure and this more often than not will leave the user hungry as the body looks to rebuild depleted fat stores.
Long Term Results: 50/100

Consistent use of Fenburn, thanks to its high caffeine content, is likely to allow active and food conscious users to experience consistent weight loss for as long as they take the product – it helps that caffeine is a natural diuretic and as such consistent use will mean a reduced intake of calories as a result. That said, these effects are dependant on diet and activity levels, and prolonged use of Fenburn increases the user’s risk of contracting side effects related to the product.
Safety: 20/100

Fenburn comes with a long list of potential side effects, and healthcare professionals discourage the overuse of caffeine products. Bitter orange is also considered dangerous. Pregnant and breastfeeding women in particular should avoid Fenburn as it may harm their child, and those with heart disease should also be careful with Fenburn as they should with any high caffeine product. Side effects range from mild afflictions such as headaches and nausea, through to far more serious conditions including heart palpitations and a risk of strokes or heart attacks, especially for users who overexert themselves during exercise.
Value for money: 50/100

Fenburn costs £34.00 for ninety capsules from the website, which is a supply long enough to last a month when the supplement is taken in accordance with the product’s recommended dosage. This works out as a little more than £1 per day, which for a powerful fat burning caffeine-based supplement is good value when compared to other similar products on the market that may cost more and prove less effective.

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Fenburn Side Effects

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Fenburn comes with a serious health warning as a result of its high caffeine content. The product should not be taken less than six hours before sleeping as the large caffeine content will affect sleep patterns. Beyond this, pregnant and breastfeeding women should avoid the product as it may damage the child, and those with heart conditions and high blood pressure should be wary as the high levels of caffeine may exacerbate conditions and potentially cause heart palpitations or strokes.

Caffeine’s potential side effects are many and varied. The least innocuous include headaches and nausea, plus what are colloquially known as ‘jitters’ where because of the increase in energy, users feel unable to stay still and experience difficulty resting. Beyond this, however, excessive caffeine usage has been linked to cardiovascular disease and brittle bone diseases like osteoporosis. Caffeine is also highly addictive, with many addicts experiencing negative withdrawal effects and cravings that again include headaches and nausea. It is advised that users of Fenburn limit their additional caffeine intake to the barest minimum to avoid over indulgence and the related side effects.

Green Tea Extract
While green tea is usually used to treat many illnesses including headaches and an upset stomach, overdosing on green tea has been known to have the opposite effect, triggering these very symptoms alongside nausea. These symptoms are especially likely to affect pregnant women or breastfeeding mothers, and is likely due to the caffeine content within green tea – however, these effects are unlikely to be experienced as a result of the green tea within an energy supplement as the dosage is nowhere near the five cups of tea needed to trigger them in most people.

Oolong Tea
Oolong tea and green tea are often very closely linked when it comes to symptoms, as they are essentially the same substance. As such, oolong tea can produce all of the same symptoms as green tea, including headaches, nausea and dizziness, when taken in extreme doses of over five cups a day. In smaller doses there have been no reported cases of adverse effects.

Bitter Orange Peel
Not enough clinical data has been gathered on bitter orange peel to form a complete list of potential side effects, but the general medical opinion is that it could potentially be dangerous to many users. Bitter orange contains chemicals that are similar to ephedra, which was recently banned by the US Food and Drug Administration. As bitter orange raises the heart rate and blood pressure, those with heart conditions are particularly at risk, as are pregnant and breastfeeding women. Those who are on medication should consult their doctor as there is a risk of bitter orange reacting to some medicines.

As capsaicin is common in peppers that are used around the world for cooking, it is unsurprising that there are very few side effects associated with taking the supplement. What few side effects capsaicin may have are generally very mild, the worst of which is the irritation or burning that many people experience when eating spicy food. In most cases this is entirely harmless, although those with an allergy to peppers may experience related symptoms from taking capsaicin.

As not much research into L-Tyrosine supplements has been conducted, there is not a lot of data regarding confirmed side effects. As it is a naturally occurring substance in the body and present in much protein-rich food, it is believed that L-Tyrosine does not have any particularly dangerous side effects, however pregnant and breastfeeding women should be careful, as with all supplements, and should seek a medical professional’s opinion. As the body uses L-Tyrosine to make thyroxine, a thyroid hormone, those with hyperthyroidism are advised to avoid L-Tyrosine supplements.

As with capsaicin, bioperine is used regularly in a variety of foods and is almost entirely free of side effects, except for the standard burning sensation in the mouth which makes up the familiar peppery taste. This is very rarely dangerous, unless pepper is inhaled in large quantities rather than ingested.

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How To Use recommends that users take three pills a day, at intervals throughout the day, with water, on an empty stomach. They recommend that for best results, one capsule should be taken in the morning approximately 30 minutes before breakfast or exercise; another should be taken approximately 30 minutes before lunch or a mid-afternoon snack; and the third should be taken ‘before training for a boost’. warns against taking the supplement after 4pm or less than six hours before sleeping due to the high caffeine content it contains.

The product also comes with a health warning as a result of its high caffeine content. Users should definitely not use the product in conjunction with any other product containing caffeine, or any other stimulants. Pregnant or breastfeeding women and those with a heart condition should not take the product, and Fenburn may react negatively with other supplements and some medications. Users who feel unwell should either reduce or discontinue use and should seek medical advice. advises that users test their tolerance to the product be beginning with only one tablet per day for the first week of using Fenburn.

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Who Makes Fenburn Ltd is a company that is based in Nottingham, which specialises in a variety of diet pills and supplements. It produces a range of products including piet pills; fat burners and appetite suppressants; slimming drinks; and weight loss patches. The company offers a guarantee on all of its products that all products sold are 100% genuine and in perfect condition when they are shipped. The guarantee does not ensure that the products are effective, safe or fit for purpose, and there is no money back option should their guarantee be broken. The company claims to regularly research and review their products to ensure that they are ‘the very best and most effective weight loss products on the market’.

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Where To Buy

This product is not currently available on the UK high street. The easiest way to get hold of Fenburm is through the website, where the product is available at £34.00 (reduced from £49.95) with £3.95 shipping for 90 capsules, which amounts to a one month supply when taken at the maximum recommended dosage. Ordering directly from also provides the user with access to the company’s Slimming+ online community. The product can also be purchased through Amazon at £37.95 with free shipping for a container of the same size, which is exactly the same price, and as such, the choice of purchasing depends on the customer’s personal preference.

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Overall Verdict

Fenburn’s high caffeine content makes it an effective fat burner, with clinical evidence supporting an increase in energy expenditure following caffeine intake. However, many of its other ingredients have proven less conclusively successful in a laboratory setting. The product also comes with a long list of potential side effects, which include some particularly severe negative effects, and the potential for it to react negatively with other supplements, other caffeinated products and some medications. Ultimately, the product is potentially effective but comes with a high risk of dangerous side effects, and as such users should take caution should they choose to use this product.

Overall: 46/100

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