There are a select few ingredients that actually help you to burn fat, while most are just junk.
The information in this article will help ensure you don’t waste your time and money on dodgy fat burners.
Table of Contents
Ingredients That Work
Green Tea Extract
All the catechin goodness.
Catechins are the active ingredients in green tea. In fact, all tea start out with catechins, but the fermentation process of oolong and black tea causes the catechins to oxidize and vanish (1).
The end result is more catecholamines, like adrenaline and noradrenaline, floating around. These guys have fat mobilizing and burning super powers, confirmed by research.
One study found green tea increases resting energy expenditure by 4% (around 100 calories or 415 kJ). That works out to around 1 extra kg of fat every other month (2).
For people interested in reducing belly fat, another study found participants lost an extra 7.4% abdominal fat, on average, when ingesting 625 mg/daily of green tea extra for 12 weeks (3). With long-term interventions like these, green tea probably works by increasing daily energy expenditure rather than increasing the proportion of fat being burnt (4).
How to take it: Green tea is a reliable fat burner ingredient without any side effects. For most people the effects don’t reduce over time either. Based on the research, you should take 625 mg of green tea extra daily.
Unlike green tea, caffeine stimulates more adrenaline to be produced rather than preventing its breakdown.
Caffeine has been shown to increase the amount of fatty acids in the blood and their availability to use for energy. You could say caffeine switches on the body’s ability to burn more fat (5).
It increases the amount of calories burnt every hour too, and some studies show that repeated caffeine intake can increase metabolic rate by 8-11% over 12 hours. The effect of caffeine on energy expenditure seems dose-dependent, so in some ways, the more the better (6).
Just be aware that caffeine’s effects diminish over time. The more you have, the less effective it becomes.
How to take it: Both low and high doses of caffeine have beneficial effects. Either take around 100 mg every couple hours, or take 8 mg per kg of bodyweight for short term, but effective, results.
Nicotine gets a bad rep, you know, because of smoking.
But when isolated from tobacco products its effects on the body are entirely different.
Nicotine naturally occurs in a number of plants such as egg plant and peppers, albeit, in very small doses. It works by mimicking a chemical in the body called acetylcholine. This chemical drives the fight-or-flight response by increasing levels of adrenaline and dopamine in the body.
Research has found that individuals taking nicotine for a cognitive benefit, without any change in diet, reduced their bodyweight by 1.3 kg over 90 days (7). Another study found nicotine gum (1-2 mg) to increase short-term energy expenditure for 3 hours, around 4-5% above baseline (8).
How to take it: Be warned that nicotine is addictive, probably more so than coffee! So supplementing short term or taking scheduled breaks every fortnight is advised. Nicotine gum with 1-2 mg seems good for a 3 to 4 hour period.
Yohimbine is an active ingredient in the Pausinystalia plant. It’s used primarily as an appetite-suppressant and fat burner.
Yohimbine works by increasing adrenaline and other fight-or-flight sympathetic nervous system hormones. In this way, it increases both energy expenditure and the availability of body fat to be burnt as fuel.
One study found that highly active soccer players experienced impressive reductions in body fat percentage, from 9.3 to 7.1%, after 21 days of supplementation (10 mg twice daily) (9).
Another study showed Yohimbine to increase fat burning between meals and during exercise. This means it may be better used during fasted states and as a pre-workout, rather than post-meal (10).
But here’s an important warning.
For people susceptible to mental health issues such as depression, anxiety or bipolar disorder, yohimbine could trigger episodes. And if you’re taking neurological medication or dealing with high blood pressure you should seek professional medical advice before using it.
In fact, that’s one of the reasons yohimbine requires a doctor’s prescription in New Zealand.
How to take it: An evidence-based approach would have you taking 0.2 mg per kg of bodyweight once or twice per day. But caution should be exercised with higher body weight.
Glucomannan is a water-soluble fiber that comes from the roots of the elephant yam (also called as konjac).
It takes up space in the stomach to help you feel full, reducing your overall calorie intake during the day. And like other water soluble fibers, it helps limit the absorption of protein and fat, and the calories that go with them (11) (12).
There have been several on glucomannan and weight loss.
In a randomized controlled trial of 176 overweight people, those taking a glucomannan supplement lost significantly more weight than the placebo (fake pill) group after 5 weeks (13).
How to take it: A dosage of 1 gram, 3 times per day is recommended for weight loss. It should always be consumed 30 minutes to 1 hour before a meal to maximise effectiveness (17).
Capsaicin is the active ingredient in hot chilli, like cayenne. This ingredient is responsible for its pungency and ability to turn up the heat!
Like many other fat burners, capsaicin works by activating the fight-or-flight system and increasing adrenaline levels. The increase in adrenaline causes a metabolic boost and greater energy expenditure.
One study found that capsaicin taken before exercise increased the amount of fat used for fuel (18). It was also shown to effectively preserve resting energy expenditure during low calorie dieting and counteract any adaptive reductions in metabolism (19).
Other studies have found the ingestion of 135 mg per day (before meals) increased daily expenditure by 119 kcals (498 kJ), and may even help you eat up to 12% fewer calories (20).
Note that the effect of capsaicin on energy expenditure seems to be more pronounced in lean individuals than those classified as obese.
How to take it: Take 100 to 150 mg per day split into equal servings and taken with your meals.
Ingredients That Might Work
Forskolin is the active compound in coleus forskohlii, an Indian perrneial plant.
Forskolin is interesting because it may also increase testosterone, protect against cancer and inflammation.
It increases levels of a particular enzyme (cCAMP) that relays messages inside many cells. This enzyme is also associated with greater rates of fat loss inside muscle and fat cells.
The research behind forskolin is very limited. One study found that when obese individuals supplemented with forskolin their body fat mass significantly decreased by 11% compared to 1.7% in the placebo group (However, no other human trials are available.
How to take: Take 250 mg of a Coleus forskohlii supplement with 10% forskolin, twice a day.
Taurine is an essential amino acid and is especially prevalent in the gastrointestinal system of humans and animals. You’ll also find it in loads of sports drinks.
It’s not historically thought of as a fat burner by researchers, but there has been one particular study showing that taurine affected fat burning during exercise.
The researchers were assessing whether taurine improved cycling ability but instead found taurine to increase fat burning by 16% during the time trial compared to the placebo (21). However, there are no other studies to back this up.
How to take it: As per the researchers, take 1.66 g of taurine 1 hour pre-workout.
Synephrine is the active ingredient in the bitter orange plant. It’s otherwise referred to as p-synephrine or Citrus Aurantium and works similarly to ephedrine, but is much less potent.
Unlike ephedrine, it seems to be harmless and without major side-effects. And, some studies show modest effects in boosting the proportion of fat being burnt at the same exercise intensity (22). Overall, supplementing with synephrine alone, or with caffeine (as is frequently the case) shows promise for increasing energy expenditure and a boost in weight loss over 6 to 12 week (23).
How to take it: A daily dosage of 10-53 mg per day, taken as 10-20 mg, thrice a day.
Ingredients That Don’t Work
CLA (conjugated linoleic acid) is a type of poly-unsaturated fatty acid that naturally occurs in some dairy products.
Why is it supposed to help with fat loss? Because the molecule is thought to interact with cellular receptors that regulate fat and glucose metabolism.
At least in theory.
In practice, there is very little research behind CLA supplementation alone or in conjunction with exercise (24).
Carnitine is a naturally occurring amino acid found in meat products in relatively high concentrations. Carnitine claims to increase the proportion of fat burnt during exercise, as well as reducing fat mass and increasing muscle mass.
Sounds great right? Unfortunately, science doesn’t back it up.
Carefully controlled studies show that ingestion of carnitine doesn’t increase the levels found in the muscle. They also show the levels of carnitine available in the muscle are more than enough to maximize its role in fat burning.
There’s no doubt that ephedrine and ephedra products are potent fat burners. But they come with a hefty risk of side effects and in some cases, legal action.
These side effects can include:
- Heart attack
Despite many individuals having used ephedrine without these side effects, the risk is real.
Raspberry ketones have enjoyed their share of the spotlight in the last 5 or so years, but not anymore.
The most recent study assessed 3 weeks of supplementation with 125 or 250 mg of raspberry ketones daily. They found reductions in body fat of 0.6% and 0.4% in the supplement and placebo group, respectively.
At these levels, the difference in body fat between the groups could easily be accounted for by variability in the measurements alone.
DHEA is an upstream metabolite of testosterone, meaning it has the potential to affect sex hormones in the body.
There are no studies showing that DHEA has an effect on reducing fat mass or burning body fat in humans.
The super nutrition directory Examine.com haven’t got round to reviewing this supplement.
This alone is a red flag.
Naringin is an active compound in grapefruit and while grapefruit has been shown to help lower weight, the ingredient in its isolated form is yet to show any benefit.
Just remember that fat burners are supplements, intended to be used on top of solid training and healthy eating.
They won’t work if you’re generally treating your body like rubbish.
For more information and insights on how to make the most of your fat burner, check out our comprehensive guide to fat burners.