Best Weight Loss Supplement Reviews and Comparisons 2023

Weight loss or fat burner supplements can be an effective addition to an existing diet and exercise plan for removing stubborn fat. But with thousands of products now available, how can you find the right one for you?

One problem is there are so many types of weight loss supplements. Carb blockers, fat burners, CLA, meal replacements, appetite suppressants, caffeine supplements, and even hydroxycitric acid (HCA) products such as Garcinia Cambogia have all proven popular.

This guide will mostly focus on fat burners, which are supplements specifically designed to help burn fat. They’re also referred to as thermogenic, because they simulate thermogenesis. This means they increase heat production in your body, which causes you to burn more calories.

So which ingredients actually work? Which fat burner supplements and brands should you be looking out for, and which should you avoid?

In this guide we’ll take a close look at the science behind the most popular fat burning ingredients, such as green tea leaf extract and garcinia cambogia. Individual fat burner reviews are also available, with comparisons between all the top brands.

Even if you’re simply looking for a quick list of the best fat burners on the market, we’ve got you covered. After analyzing more than 50 leading fat loss supplements, we created an ultimate science-backed list of products that are actually worth buying.

What Is a Fat Burner and How Does It Work?

Thermogenics are fitness supplements commonly referred to as fat burners. They’re designed to increase your metabolic rate and burn more calories in less time, which can lead to weight loss.

Some fat burners, such as Biotest Hot Rox and Nutrex Lipo 6 also contain ingredients to boost the natural process of lipolysis – the natural breakdown of fat stored in fat cells. However, even if you include a fat burner supplement in your routine, it’s important to already be in a caloric deficit, preferably through healthy diet and exercise.

Modern fat burners are often blends of herbs and stimulants that work together to increase your body temperature, to promote thermogenesis. Such ingredients include green tea extract, caffeine, and rhodiola rosea extract. Because caffeine has a mild diuretic effect, you should always boost your water intake to compensate. At least 20-24 ounces per day is a good starting point, but more if you lead a physically active lifestyle.

Top 10 Best Weight Loss Supplements

According to a 2017 report by Marketdata Enterprises, the U.S. weight loss industry is worth a record $66 billion. This includes everything from Weight Watchers and Jenny Craig, through to gym memberships for LA Fitness, and even memberships to fitness tracking services like MyFitnessPal.

With so much money at stake, it’s no surprise that the number of weight loss supplements has exploded in recent years. They often claim to be the best natural fat burner, designed to prevent hunger cravings, increase metabolic rate, improve appetite control, and burn fat fast.

But how much is based on real science? Clinical, long-term double-blind placebo trials are hard to find, but there are a few proven ingredients to look out for.

We analyzed the labels of over 100 weight loss supplements to bring you what we believe to be the best on the market. No marketing hype weight loss pills, just some of the highest rated fat burners for men and women, to destroy stubborn fat and help you reach your weight loss goals.

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Other high quality weight loss supplements worth mentioning:

Types of Weight Loss Ingredients

Weight loss supplements often use a combination of fat burning ingredients and appetite suppressants. We’ve listed three of the most common types below.

Who Are Weight Loss Supplements Designed For?

Science has shown that certain ingredients can increase the rate of fat loss. But it’s important to remember that so-called ‘weight loss pills’ aren’t a miracle cure on their own, and any weight management supplement should always be combined with a healthy diet and regular physical exercise.

Weight loss supplements and fat burners are suitable for anyone that wants to lose weight or boost their metabolism. Whether it’s for health reasons, improve your quality of life, or cut down for a bodybuilding competition. However, we would always recommend seeking professional advice from your local health professional before adding starting any new supplement routine.

How Much Should You Take?

Typically, fat burners aren’t taken over a long period of time. A standard rotation would be 14 days on followed by 14 days off, but as always, consult a medical professional before taking any new supplement. We would also avoid taking fat burners after 2pm, due to the stimulant effects of caffeine and the negative effects it can have on sleep quality.

Because of the potential dangers of double-dosing on certain ingredients, we would also advise against taking more than one weight loss supplement or fat burner at a time. In terms of dosing, always follow the ingredients on the label.

What Happened To Ephedra?

Ephedra is a herbal supplement that occurs naturally in the Chinese herb ma huang. When it first came to market, it quickly gained popularity amongst athletes and gym goers as a weight loss aid and energy boost.

Unfortunately, the effects weren’t always positive. Increased blood pressure and arrhythmias are just two of the potential side effects, and it was banned by the FDA in 2004 after being linked to several deaths. This ban was put in place after more than 16,000 reports of adverse health effects, and roughly 155 deaths.

Which Fat Burner Gives You the Most Energy?

If you’re looking for a fat burner with high levels of caffeine and energy boosting stimulants, Hydroxycut is the way to go.

The standard Hydroxycut Advanced version is relatively low in caffeine, with 180 mg per serving, in addition to a natural energy boost from vitamins B6 and B12. But step this up to Hydroxycut Hardcore Elite, and you’re looking at 270 mg of caffeine anhydrous per serving.

If you’re looking for the strongest energy boost Hydroxycut has to offer, then check out their Hardcore Next Gen supplement. With 290 mg of caffeine anhydrous and 400 mg of green coffee bean extract per serving, it’s their most potent energy and weight loss blend.

To put this in perspective, Lipo 6 Black Ultra Concentrate contains 294.5 mg of an ‘ultra-concentrated fat destroying complex’, which lists caffeine anhydrous as one of 5 ingredients.

ENGN SHRED from Evlution Nutrition is an excellent choice for a pre-workout thermogenic fat burner. Each scoop contains 260 mg of natural caffeine and green tea extract per serving, alongside a range of scientifically proven fat loss ingredients, such as CLA (500 mg). You’re also getting high levels of a vitamin B complex for natural energy (vitamin B6 100% DV, vitamin B12 417% DV).

Side Effects of Weight Loss Supplements

Slimming pills, weight loss pills, thermogenic fat burners, and diet pills. These are just some of the terms used to loosely describe supplements or medication that can help you lose weight.

Licensed pharmaceutical drugs should only be described by doctors, while unlicensed pharmaceutical drugs are often available at private slimming clinics. But it’s the over-the-counter weight loss supplements that often cause the most concern.

The likelihood of experiencing any side effects from these products is dependent on the ingredients. For example, Alli orlistat is generally suitable for long-term use (12-16 weeks+, based on results), but the ingredients mean it interferes with fat absorption. In some cases, this can lead to changes in bowel function due to the unabsorbed fat.

But with most weight loss supplements you can buy online, the main ingredients are green coffee bean extract (GCBE), green tea extract, CLA, or caffeine. These are much less likely to produce an adverse reaction.

Drugs.com has a comprehensive list of FDA approved weight loss drugs, such as Belviq, Contrave, and Saxenda, together with their common side effects. This is currently outside the scope of this guide, but if you’re interested in finding out more about prescription weight loss drugs, you can find the article here.

Top 10 Best Weight Loss Ingredients

The weight loss industry is notorious for false claims about the effectiveness of products. There are countless high-profile examples, including the $40 million FTC settlement from Skechers over their Shape-ups ‘toning’ shoes.

Weight-loss supplements have faced legal action due to similar false claims, such as the $40 million judgement of Luna Biomedical, Inc. for the deceptive marketing of Amberen. Amberen was a dietary supplement for women over 40, which made unsupported claims about its ability to help women lose weight and belly fat.

So, with no shortage of misinformation, and some supplements containing dozens of ingredients, how do you know what actually works? What are the best weight loss ingredients to look out for?

Conjugated linoleic acid (CLA) is a naturally occurring fatty acid that’s found in beef and dairy products. CLA is most commonly known for its ability to reduce body fat, as proven in animals. But how well does this work for humans? How much should you take per day and is it safe to supplement with CLA year-round?

Scientific studies (what dose?)

Whigham LD et al. performed a meta-analysis of human studies where CLA was used as a dietary supplement. By analyzing the dosages used in these studies, a median dose of 3.2 g CLA/d was found to be more effective than placebo for a reduction in fat mass.

This is backed by a paper published in the International Journal of Obesity. Waltras AC et al. performed a randomized, double-blind, placebo controlled study, where forty overweight subjects received a daily dose of 3.2 g CLA for 6 months.

Their results showed that CLA significantly reduced body fat gain during the holiday season, without affecting your level of physical activity, dietary intake, or resting metabolic rate (RMR).

So, 3.2 g/day seems to be the maximum recommended level, but what happens when you take a larger dose? Perhaps as high as 6 or 7 g/day?

Blankson H et al. performed a randomized, double-blind study, which included 60 overweight or obese volunteers. These 60 volunteers were assigned to five groups, receiving a placebo, (9 g olive oil), 1.7, 3.4, 5.1 or 6.8 g of CLA per day for 12 weeks.

After 12 weeks, 47 subjects had completed the study. Results showed a significantly higher reduction in body fat mass for the CLA groups compared to placebo. This reduction was found to be most significant for the 3.4 and 6.8 g CLA groups, but no additional reduction in body fat mass was achieved using doses higher than 3.4 g CLA/d.

Bottom Line: Supplement with a maximum of 3.4 g CLA/day to experience the greatest reduction in body fat mass.

How long can you supplement with CLA for?

A separate study, published in the American Journal of Clinical Nutrition, tested the effects of long-term CLA supplementation (1 year). Researchers assigned 180 male and female volunteers to 3 different groups: CLA-free fatty acid (FFA), CLA-triacylglycerol, or placebo (olive oil).

The results of the study showed that the CLA-triacylglycerol group experienced the greatest reduction in body fat mass, but that CLA-FFA was also a more effective option than placebo.

Further research by Chen SC et al. aimed to determine the effect of CLA on weight loss in obese Chinese subjects. The study last 12 weeks, with subjects randomized to receive 1.7 g of cis-9, trans-11 and trans-10, cis-12 CLA or placebo (salad oil).

Of the sixty-three subjects that completed the study, 30 had supplemented with CLA. This led to a reduction in bodyweight, BMI, subcutaneous fat mass, and waist-to-hip ratio, with no adverse side effects.

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(stop formation of new fat cells, carbohydrate blocker):
Garcinia Cambogia is a pumpkin-shaped citrus fruit that grows naturally in Southeast Asia and India. Hydroxycitric acid (HCA) is one of the main ingredients, which has traditionally been used in cooking, but research has also proven it beneficial for weight loss.

Some of the most popular Garcinia cambogia supplements on the market come from NatureWise, Quality Encapsulations, Potent Organics, and Schwartz.

But can Garcinia cambogia work on its own, and does it cause weight gain?

In 2007, a study was published in the Phytotherapy Research journal, testing the effects of Slim339. The ingredients were a combination of Garcinia cambogia and calcium pantothenate.

This double-blind, placebo-controlled study had a treatment period of 60 days, after which weight loss was recorded for each subject. The average reduction in body weight for the group receiving Slim339 was 4.67%, compared with 0.63% for the placebo group.

A separate study by Hayamizu K et al. tested the effects of Garcinia cambogia extract on visceral fat accumulation. Subjects aged 20 to 65 years were split into two groups for a period of 12 weeks, with one group receiving 1000 mg of HCA per day, and the other a placebo.

After 12 weeks, both groups were assigned a placebo for a further 4 weeks to assess any rebound. The results showed no rebound effect, with no severe adverse effects, and a significant reduction in visceral fat for the Garcinia cambogia group.

Further research has been carried out on a water-soluble calcium hydroxycitrate in Garcinia atroviridis. In this study, fifty women with a BMI over 25 kg/m were assigned to two groups; one with HCA, and one with placebo. Each subject followed a strict diet of 1000 Kcal/day.

After 2 months, the HCA group had lost twice as much weight compared to the placebo group (2.8 kg vs. .4 kg) and at a faster rate.

As well as its potential weight loss benefits, some studies show HCA to be effective at regulating weight gain.

A study by Leonhardt M et al. tested HCA intake on rats after 10 days of substantial weight loss. This was found to suppress body weight regain for at least 3 weeks after starting supplementation with 3% HCA.

A Super CitriMax (HCA-SX) version is also available, which is completely soluble in water, therefore providing higher bioavailability. This was found to be effective in reducing the body weight and BMI of healthy and obese adults are 8-week clinical trials.

One such study was performed in Elluru, India, with 60 moderately obese subjects between the ages of 21 and 50. Each subject received a 2000 kcal/day diet, and was assigned to one of three groups.

Group A received 4667 mg of HCA-SX, while group C was given a placebo. At the end of the 8 weeks, the body weight and BMI decreased by 5-6% in groups A and B, with no significant benefit for group C (placebo). Total cholesterol level was also lower in groups A and B.

NatureWise have a Super CitriMax Garcinia Cambogia supplement available, which is currently one of their best sellers.

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Chitosan is a popular over-the-counter dietary supplement which is often used as an ingredient in weight loss products. However, there is minimal clinical evidence to say it’s any more effective than a placebo.

One study attempted to evaluate the effects of chitosan using a 24-week randomized, double-blind, placebo-controlled trial. Each of the 250 participants were assigned a course of treatment; 3 g chitosan/day, or placebo.

The results showed that participants in the chitosan group lost the most weight. But the weight loss difference between the chitosan and placebo groups wasn’t considered significant.

A separate meta-analysis, published in the Obesity Review journal, came to a similar conclusion. Fourteen trials involving 1071 participants were included in the review, where chitosan was supplemented for a minimum of 4 weeks.

Taking the results from the high-quality trials, this review concluded that the effect of chitosan on bodyweight was minimal, and unlikely to be of clinical significance.

A third study was also published in the European Journal of Clinical Nutrition. In this case, thirty-four overweight volunteers were assigned to receive either four capsules of chitosan or a placebo, twice daily for 28 days.

After 4 weeks, researchers found no significant difference in body mass index. They concluded that chitosan did not reduce body weight in overweight subjects.

Bottom Line: Not enough evidence to prove chitosan is effective for weight management or weight loss.

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One study, published in the British Journal of Nutrition, analyzed the long-term effects of very-low-carbohydrate ketogenic diets. This was a meta-analysis of existing research, which compared a VLCKD diet (no more than 50 g carbs per day) against a low-fat diet (less than 30% of energy from fat).

The results showed that individuals assigned to the VLCKD group lost more weight over the same period of time than those in the low-fat diet group (more energy, appetite control).

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Green tea extract (GTE) has been linked to numerous health benefits, such as lowering cholesterol, faster resting metabolic rate, boosting mental alertness, reducing the risk of Parkinson’s disease, and even cancer prevention.

But is there any clinical evidence to prove green tea extract is a powerful fat burner?

One study showing a clear reduction in abdominal fat was performed by Maki KC et al., and published in the Journal of Nutrition.

In this case, 132 subjects were assigned to one of two groups. Group 1 consumed a green tea catechin drink (625 mg of catechins and 39 mg of caffeine), while group 2 simply consumed 39 mg of caffeine, with no catechins. Each subject was also asked to engage in at least 180 minutes of moderate intensity exercise per week.

After 12 weeks, the catechin group had noticed the most significant reduction in total abdominal fat area and subcutaneous abdominal fat area.

A separate study by Ota et al. tested fat oxidation rates as a result of supplementing with GTE. After 2 months of light treadmill exercise (5 km/h for 30 min 3 times/wk) and consuming a drink with 570 mg catechins daily, fat oxidation rates 24% higher than placebo were observed.

An epidemiological study was also performed in Taiwan by Wu et al. in 2003. Following tea consumption of 434 mL/day for more than 10 years led to a lower percentage of total body fat, smaller waist circumference, and decreased waist-to-hip ratio.

Some studies have also highlighted how important it is to combine green tea catechins (GTCs) with caffeine if you want to experience the greatest reduction in body weight.

A systematic review of controlled trials was performed by Phung et al., to determine whether caffeine was necessary to experience the weight loss benefits of green tea catechins.

After analyzing fifteen studies, it became clear that GTCs with caffeine decreased BMI, body weight, and waist circumference more effectively than GTCs or caffeine alone.

Bottom line: Green tea extract can boost fat burning, but is very dose dependent. It should also be combined with caffeine for the best results. 600 mg of catechins and 65 – 110 mg of caffeine per day appears to be best for weight loss, based on existing research.

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Green coffee bean extract (GCBE) has been tied to numerous health benefits, such as lowering blood pressure and boosting your metabolism. It’s also a popular ingredient in weight loss supplements, but can it help you lose weight and burn fat?

A meta-analysis of existing GCBE research was published by Gastroenterology Research and Practice. Researchers took an initial 2160 articles and cut them down to just 3 randomized clinical trials that were worthy of inclusion (142 total participants).

One of these studies was published in the Journal of International Medical Research. Across a 12-week double-blind study, researchers tested the effects of coffee on 30 overweight people. They found that coffee enriched with chlorogenic acid (high levels of which are found in GCBE) may result in reduced body mass and body fat, compared to instant coffee.

A separate study of GCBE was performed on high-fat diet (HFD) induced mice, over a period of four weeks. Levels of GCBE supplementation were tested at 50, 100, and 200 mg/kg. The study concluded that GCBE had a potential anti-obesity effect through lowering body fat accumulation.

Similar results were seen from supplementing the diets of HFD mice with 300 mg/kg of green coffee bean extract. Research by Su Jin Song et al. found this was the minimum effective dose for preventing body weight gain, fat accumulation, and insulin resistance in mice fed the HFD for 11 weeks.

However, we were unable to find clinical research that showed human participants losing weight as a clear result of GCBE. No universally accepted intake level was available, and there are no guidelines over how much weight you can expect to lose over a set period of time.

Bottom Line: Supplementing with GCBE at 300 mg/kg has shown to be effective at reducing fat accumulation in mice, but there is limited research to prove this is true in humans.

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Acetyl-L-Carnitine is one of the most popular ingredients in weight loss supplements. This includes the bestselling Lean Mode capsules from Evlution Nutrition (500 mg), and Burn XT from Jacked Factory (700 mg). It can also be purchased as a single ingredient supplement, from companies such as NOW Foods, BRI Nutrition, and Doctor’s Best.

The goal of supplementing with carnitine is to transport long-chain fatty acids to your cells’ mitochondria to produce energy.

So, does L-carnitine work for fat loss, and what results can you expect?

One study, published in the journal ‘Metabolism: Clinical and Experimental’, tested the effects of l-carnitine on the rate of fat oxidation. Twelve volunteers were assigned a diet with or without l-carnitine, at a dose of 3 g/day for 10 days.

The results showed a significant increase in fat oxidation, with no change in the rate of protein synthesis.

However, this is just one study, with a very small sample size. We were unable to find any other human trials that show a positive link between carnitine and fat loss.

Mehmet Oz, MD, actually backtracked on earlier support for carnitine supplements after new research was released suggesting L-carnitine poses a risk to heart health. This is irrespective of where your carnitine intake comes from; either supplement form or from red meat.

Bottom Line: Not enough evidence to prove carnitine is effective for weight management or weight loss. Some research has also linked carnitine to an elevated risk of heart disease.

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Many weight loss supplements contain caffeine, either as caffeine anhydrous or as part of a green tea (catechin) and caffeine combination. This is designed to boost resting energy expenditure (REE) and decrease levels of fatigue commonly associated with low calorie diets.

But is there any science to back this up? Can caffeine alone act as a thermogenic fat burner, or simply provide an energy boost?

One study tested the effects of a 340 mg formula (caffeine and green tea extract as the main ingredients) on twelve subjects. The results showed resting energy expenditure was increased for more than four hours after consumption. Perceived alertness and energy levels were also significantly increased.

A separate meta-analysis of catechin rich teas and caffeine was also published in the Obesity Reviews journal. The goal was to determine whether caffeine-only supplementation increased thermogenesis and fat oxidation.

Six studies were chosen for inclusion, which were used to compare the effects of catechin-caffeine mixtures against caffeine-only supplements.

The results showed both types of supplement increased energy expenditure significantly over a 24 hour period. However, fat oxidation was only significantly increased by the catechin-caffeine combinations.

In a 2002 study, published in the International Journal of Obesity and Related Metabolic Disorders, researchers compared the weight loss benefits of placebo to a herbal Ma Huang/ephedrine/caffeine blend.

Of the 167 subjects that took part in the study, 84 were assigned to placebo, with 83 receiving the herbal treatment. After 6 months, the herbal ephedra/caffeine (90/192 mg/day) combination was found to promote weight loss and fat loss, without significant side effects.

Further research was published in 2005, which supports the weight maintenance benefits of a green tea-caffeine formula.

In this trial, 76 overweight subjects followed a low calorie diet for 4 weeks, followed by 3 months of weight maintenance (WM). During the WM phase, subjects received either a placebo, or green tea-caffeine mixture (270 mg epigallocatechin gallate + 150 mg caffeine per day).

The results showed that high caffeine consumers reduced weight, fat mass, and waist circumference more than low caffeine consumers.

Bottom line: Caffeine alone won’t help burn fat, only increase energy levels. Combine caffeine with ephedra or catechins from green tea to experience an increase in weight loss. Caffeine levels of 150 mg/day have shown to be beneficial.

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The human body requires very low levels of the chromium mineral, making it an essential trace element. It’s typically used to improve blood sugar control for diabetics, but has also been used in treatments for depression, bipolar disorder, and to reduce levels of bad cholesterol.

Chromium has also been found in weight loss supplements, such as the bestselling Garcinia Cambogia extract from Quality Encapsulations (200 mg).

So, if you want to lose weight or decrease body fat, is chromium something worth taking?

One study, published in the Journal of Alternative Complementary Medicine, assessed the effect of chromium picolinate (CP) on weight loss.

In this trial, 80 healthy, overweight adults were randomly assigned to either a placebo or 1000 mcg of CP/day, for a period of 24 weeks. After the full 24 weeks, there was no difference in BMI reduction between the two groups.

The study concluded that supplementation with 1000 mcg of CP did not affect weight loss.

A separate meta-analysis of nine randomized controlled chromium trials was published in 2013. The duration of studies ranged between 8 and 24 weeks, with a total of 622 participants; 346 receiving chromium picolinate and 276 receiving placebo.

The results from doses up to 1000 µg were grouped and analyzed. This revealed participants in the CP group lost just 1 kg more than those taking a placebo.

Further research was published in the Journal of Sports Medicine and Physical Fitness, which evaluated chromium picolinate as a fat-reduction aid.

Participants were 79 men and 16 women, selected from active-duty Navy personnel, with a body fat of 22%+ for men, and 30%+ for women. They were then randomly split into two groups; one receiving 400 mcg of chromium picolinate, and the other a placebo.

After 16 weeks, the study found no significant reduction in body fat or body weight between groups. Researchers concluded that chromium was ineffective at enhancing body fat reduction.

Bottom Line: Existing clinical studies have shown chromium picolinate (CrPic) supplementation has minimal impact on weight loss. We were unable to find a single study that supported CrPic as a weight loss aid.