Top 3 Best (and Worst) Fat Loss Supplements

If you want to know what the best supplements to burn fat and lose weight are, as well as the worst supplements for fat loss, then you want to read this article.


Diet pills, fat burners, weight loss aids, appetite suppressants, whatever you want to call them are, the weight loss industry is bigger than ever.


When you consider that ⅔ of the adults in the United States and ⅓ of the world’s population are overweight and that approximately 40% of the population is on a weight loss diet at any given time, it’s easy to see that fat burners are in high demand. And trust me, there’s no shortage of products masquerading themselves as weight loss supplements, begging to be picked by you.


Yet, when you use them, you either feel overstimulated, on edge, anxious, or wondering why you wasted your money.


That’s where this list comes in.


We’ve assembled a list of the top 3 ingredients you do NOT want in your fat burner along with the three ingredients you should definitely want in your fat burner.


Let’s get right to it!

The Worst Supplements for Fat Loss

Conjugated Linoleic Acid (CLA)

Conjugated linoleic acid (CLA) is a naturally occurring polyunsaturated fatty acid (similar to omega-6 fatty acids) found in beef and dairy products. Our own bodies endogenously produce CLA as well.


It has been a mainstay stimulant-free fat loss supplement for years and it’s often touted as a “healthy” fat. This is primarily due to the fact that early research using CLA noted that it did, in fact, help people lose body fat.[1,2]


However, for every study shown CLA enhances fat loss, there are an equal number of studies demonstrating that CLA supplements are not more effective than placebo for weight loss.


And, there’s even some research showing that CLA supplements actually result in weight gain![3,4]


But, gaining a few extra (unwanted) pounds of fat from your fat burner isn’t the worst of your concerns when supplementing with CLA….not even close.


As it turns out, there may be some fairly serious consequences to using CLA supplements.


A pair of meta analyses, both published in 2017, detailed that using CLA supplements led to increased inflammatory markers, including c-reactive protein (CRP) and tumor necrosis factor-α (TNF-α).[5,6]


Why is this bad?


Well, chronic, systemic inflammation is a key factor in a wide assortment of diseases including:


  • Diabetes

  • Metabolic syndrome

  • Heart Disease

  • Alzheimer’s

  • Parkinson’s

  • Rheumatoid arthritis

  • Chronic Obstructive Pulmonary Disorder (COPD)

  • Irritable Bowel Syndrome

  • Lupus

  • And many other chronic diseases


Other research indicates that consuming large doses of CLA supplements can lead to fat buildup in the liver (i.e. fatty liver), which is an hallmark sign of metabolic syndrome and diabetes.[7,8]


Continuing with the list of reasons note to consider a CLA supplement for your weight loss needs, it also has been documented to lead to:


  • Stomach pain

  • Nausea

  • Diarrhea

  • Flatulence[9]


And as if all of the above reasons didn’t warrant you avoiding CLA altogether, then maybe this will -- CLA may cause insulin resistance and reduce HDL ("good") cholesterol.[10,11]


EAA Max Energy provides a low calorie option to enhance energy levels and support performance during your fat burning workouts.



L-carnitine is another common ingredient in many of the best selling fat burning pills on the market. And, when you understand the theory behind L-carnitine you could understand why people might think it’s actually one of the best ingredients for weight loss.

So, what is L-Carnitine?

Carnitine is an important compound that allows your body to burn fat for fuel. It’s found in many foods, including meat, milk, and eggs. Your body can also synthesize L-Carnitine from two essential amino acids, lysine and methionine. And, over 90% of your body’s carnitine stores reside in your muscles.


How does Carnitine Help Burn Fat?

On their own, fatty acids cannot enter the mitochondria (the mini “nuclear reactor”) of the cell to be burned (“oxidized”) for energy. They need a transport or “shuttle” to carry them into the mitochondria.


L-carnitine is this “shuttle” that taxis fatty acids into the mitochondria.


Therefore, theoretically speaking, by increasing your body’s amount of carnitine, you would be able to burn more fat. The easiest way to boosting carnitine levels (without having to chow down a bunch of meat) is by taking L-carnitine supplements.


However, while good in theory, this hasn’t exactly panned out in research trials.


First and foremost, regular free form l-carnitine (the kind you see in those L-Carnitine 1500 supplements) is poorly absorbed by most people. In fact, research shows that L-carnitine supplements are really only effective for increasing carnitine stores in those with carnitine deficiencies, such as vegans, vegetarians, or the elderly (e.g. people who do not eat much meat).


Note: This is why Pyretic and Hurakan use the more bioavailable and effective forms of carnitine, such as Acetyl L-Carnitine.


Other studies note that when L-carnitine has increased muscle carnitine stores in those not deficient in the compound subjects had to consume a heaping 80-94 grams carbohydrates so as to improve carnitine absorption.[11]


Now, let’s stop and think about that for a second, if you’re dieting, carbohydrates are typically restricted. Is it really worth blowing a decent chunk of your allotted carbohydrate intake for the day to a supplement that might lead to a little better fat oxidation?


Not really.


And, also remember that fat oxidation (“burning”) is not the same thing as fat loss. Just because your body is burning fat doesn’t mean you're losing weight. Case in point, people following a ketogenic diet.


Yes, they’re burning fat all day long, but if they are not in a calorie deficit they will not lose weight. But, let’s not go off on a keto tangent. Let’s get back to carnitine and the heaping helping of carbs you need to take with it.


As you know, when you consume carbohydrates, insulin levels rise, which brings about nutrient storage and a reduction in fat burning.


Here’s the real “nail in the coffin” regarding L-carnitine supplements though, and why they are one of the worst ingredients for fat loss.


In the studies where subjects experienced an increase in muscle carnitine stores, they didn’t actually lose any weight![12]


And, if you’re thinking about supplementing with L-carnitine for its purported improvements exercise performance, think again. A pair of recent trials have concluded that supplementing with L-Carnitine has no significant impact on performance.[14,15]


Health Concerns Regarding L-Carnitine

Aside from the fact that L-Carnitine won’t do much of anything in regards to helping you lose weight, it may come with some very serious health consequences. A pair of recent studies have highlighted an association between carnitine intake levels and an increase in levels of a compound known as TMAO.


What is TMAO?

TMAO stands for “trimethylamine N-oxide”.


When you consume certain nutrients, such as choline or L-carnitine (both prevalent in meat and energy drinks), the bacteria in your gut break these compounds down and produce trimethylamine (TMA).


The liver then converts TMA into TMAO, which isn’t all that beneficial for your heart as it turns out.


Recent studies note a strong association between high levels of TAMO and an increased risk for clot-related events, including heart attack and stroke.[16]


Most recently an analysis of 2200+ patients with coronary artery disease found that high blood levels of TMAO were linked to higher rates of premature death.[17]


In fact, the individuals with the highest TMAO levels had a four-fold greater risk of dying from any cause over the subsequent five years.


Exogenous Ketones (BHB Salts)

Carbohydrates have been deemed “persona non grata” recently, and with this demonization of all things starchy and sugary comes the rise in popularity of low carb and ketogenic diets.


Concurrent with this renewed interest in the low/no-carb lifestyle the past few years, has been a steady influx of supplements designed to put you into ketosis “immediately” after consumption. These keto supplements typically are built on a foundation of exogenous ketones, such as BHB salts and ketone esters. And you’re beginning to find BHB salts in everything from pre workouts to post workouts and even the occasional nootropic.


For those of you unaware, exogenous ketones are readily used source of energy marketed to help “ease” an individual’s transition to ketosis, alleviate symptoms of “keto flu”, and “teach” you body how to burn fat for fuel.


These BHB salts provide your body with a quick burning source of energy while your body figures out how to once again rely on fuel as its main source of energy as opposed to glucose.


However, there’s been very little research demonstrating that BHB salts are effective for reducing symptoms of keto flu (i.e. brain fog, lethargy, muscle cramps, headaches, constipation)[18] or “easing” eases the transition to ketosis symptoms of “keto flu”.


Regarding fat burning, BHB salts will definitely have you burning fat, but not necessarily the kind that’s stored around your midsection.


Why is that?


When you take BHB salts, you are supplying your cells with exogenous ketone bodies. Since your body is getting a source of quick-burning fuel from outside, it doesn’t need to rely on its energy stores to run itself.


As a result, your body decreases its own production of ketones, meaning you’re reducing the amount of stored body fat you’re burning (not exactly ideal when trying to lose weight as fast as possible).


Now, once your body finished burning through the exogenous ketones, it will resume normal ketone production from your body’s fat stores.


Another reason to avoid using BHB salts is due to the fact that your body has feedback mechanisms that reduce ketone production when ketone levels get too high. What this means, is that if you’re chugging BHB salts all day long thinking that you’re doubling down on your fat burning, you’re really hindering your own fat loss, as your body will scale back its production of ketone bodies to prevent your blood from becoming too acidic.[19,20,21]


That’s not all.


Ketone supplements (BHB salts) have been noted to increase insulin secretion, which inhibits lipolysis (and fat burning).


This also holds true for the glucose-burning individual. If you consume carbohydrate-rich foods all day long, blood sugar and insulin levels rise. This reduces fat burning and promotes fat storage.


Basically, when it comes to BHB salts the truth is that while they make you burn fat for fuel, they aren’t really helping you burn body fat or lose weight.


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Top 3 Research-Backed Fat Loss Supplements


Without question, the most popular fat loss supplement is caffeine. It’s been studied thousands of times, proven safe when consumed in reasonable doses (the same of which can’t be said for other common weight loss aids), and effect.


You know caffeine gives you greater energy and alertness, but have you ever stopped to think about how caffeine increases energy?


The primary way in which caffeine exerts its energy and mood-enhancing effects is through antagonism of adenosine receptors. Adenosine is a neurotransmitter that’s associated with feelings of fatigue and lethargy.


FYI, adenosine also forms the “backbone” of ATP.


Since caffeine resembles the shape of adenosine, it can dock to adenosine receptors and “block” adenosine from binding. In doing so, caffeine increases wakefulness and alertness.[22] But that’s not all.


Second to antagonizing adenosine receptors, caffeine also increases production of dopamine (a mood and motivation molecule) as well as adrenaline -- one of the most important fat burning catecholamine in the body.[23]


More specifically, adrenaline can causes an increase in an individual’s metabolic rate.


Caffeine also enhances weight loss through a number of indirect mechanism as well. Studies demonstrate that caffeine can[25,26,27]:


  • Stimulate lipolysis

  • Increase energy expenditure

  • Reduce appetite

  • Enhance the effects of other fat burning supplements

  • Boost exercise performance (which helps increase the number of calories your burn during training)



Yohimbine is a powerful alkaloid extracted from a species of African plant called Pausinystalia johimbe ( or simply yohimbe). Research has shown it to be an effective supplement for losing weight, but the manner in which yohimbine helps burn fat is a bit tricky.[28]


Adipocytes (your fat cells) contain two types of receptors that dictate fat storage (alpha receptors) or fat release (beta receptors).[29] Lipolysis is the process by which fatty acids stored in fat cells are released into the bloodstream to be burned for energy.


Now, when fat burning catecholamines, such as adrenaline and noradrenaline, bind to beta receptors, fat cells “unlock”, initiating lipolysis, and stored fatty acids are available for beta-oxidation. However, when catecholamines bind to alpha receptors, lipolysis is for all intents and purposes stunted.[30]


These receptors are at the core of your “stubborn fat” problems, as the areas of fat on your body that are the most difficult to lose contain high amounts of alpha receptors and lower amounts of beta receptors.


Now, here’s where yohimbine comes in as the ultimate “stubborn fat” burner.


Yohimbine blocks alpha receptors[31], which leaves more catecholamines available to bind to beta receptors, free the stored fatty acids, and allow you to burn stubborn belly fat.


Now, yohimbine isn’t all rainbows and sunshine, it does come with one “catch” -- elevated insulin levels reduce its effectiveness.[32] In other words, if you want more than just the stimulatory actions of yohimbine, you need to take it in a fasted state.[33]


Yohimbine’s benefits don’t stop there, though.


It does more than help you lose fat faster: research shows that it also improves exercise performance[34] and it’s particularly effective at fighting off physical fatigue and increasing time to exhaustion.[35]



Forskolin is the bioactive compound present in the Ayurvedic plant Coleus forskohlii, where it has a long history of use treating disorders of the respiratory and cardiovascular systems.


Studies shown that supplementing with forskolin raises plasma and intracellular levels of a molecule known as cyclic adenosine monophosphate, or cAMP for short.


cAMP serves as a vitally important intracellular "messenger” that impacts numerous physiological processes including metabolism of sugar, fats, and glycogen..[36]


cAMP and ATP (the cellular “currency” of energy production) have a rather unique relationship inside the cell. When ATP levels are high it signals to the cell that it has plenty of energy. This tells your body it needs to store nutrients and build tissue.


However, when cAMP levels are elevated, it signals to the cell that ATP is low, which causes the cell to initiate processes to generate more ATP by using its stored energy (i.e. fat).


Forskolin triggers the enzyme adenyl cyclase, which converts ATP to cAMP, leading to a significant increase in the amount of cAMP in a cell, and thus igniting the energy-burning processes.[37]


Studies have demonstrated that supplementation with forskolin speeds up fat loss and boosts testosterone levels.[38,39]


The Bottom Line on Fat Loss Supplements

The supplement industry is riddled with overpriced, underdosed products touting themselves as weight loss aids, when in reality they’re a bunch of glorified stim pills built on bogus ingredients and bad science.


Primeval Labs believes in doing things differently, choosing instead to formulate weight loss aids built on science and actually enhance weight loss.


That’s why we’ve created Hurakan and Pyretic.


Hurakan is our stimulant-based fat burner formulated to deliver smooth, long-lasting energy that boosts metabolism, increases energy expenditure, and helps limit appetite all while helping improve mood and alleviate the “brain fog” commonly experience while dieting.


Pyretic is our stimulant-free weight loss supplement that can be used on its own or stacked with Hurakan for added metabolism revving, appetite suppression, and nutrient partitioning.


Click here to learn more about our line of scientifically-formulated weight loss formulas and decide which is best for YOUR needs!


Click here to learn more about Primeval Labs stimulant-based fat burner and thermogenic supplement Hurakan.


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