Stacker 2 Review – Should You Add This Fat Burner To Your Routine?

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By Jack Cincotta, MS

Reviewed by Juliana Tamayo, MS, RDN - Last Updated

Stacker 2 Review

If I were to place a bet on the most frequently consumed supplements, I’d pick fat-burners. After all, many people in today’s society are trying anything they can to lose body weight and, more importantly, body fat.

But, there seems to be an endless number of fat-burners out there, so it can be hard to figure out which ones might actually help, and which ones are probably just a waste of money. So in this review, we’re going to focus on one particular fat burner supplement called Stacker 2. We’ll dive into this fat burner’s ingredients, claims, benefits, and more to see if it’s truly an option worth considering.

Ready to dive into this Stacker 2 review? Let’s get started!

About Stacker 2

Stacker 2, as the manufacturer claims, is “brought to you by the manufacturers of the World’s Strongest Fat Burner,” so it obviously designed as a product for fat loss. The manufacturer is NVE Pharmaceuticals, which has been making fat-burning supplements for over 35 years.

Stacker 2

Stacker 2 is supposed to be NVE Pharmaceuticals’ strongest fat-burning product, though it is different from the original because it is now ephedra-free (ephedra is banned by the FDA). 

Stacker 2 Benefits

With its blend of researched ingredients, Stacker 2 is supposed to help you burn fat, increase energy levels, and lose weight. They claim that their energy-enhancing effects surpass most other fat-burning products out there. These benefits are attributed to the blend of plant and herbal extracts, along with various stimulants. And it is supposed to be safer than the original version that included ephedra. 

So, less fat, more energy, and better body composition? Sounds like a good deal. But read on to find out if these benefits are likely to actually occur!

Stacker 2 For Fat Burning

Stacker 2 Ingredients

Stacker 2 consists of a proprietary blend, a Tri-Gugglytoid3 complex, and caffeine. Now, of course, there are ingredients within the blend and complex, so here are all of the listed ingredients: 

  • Proprietary Blend (198mg) consisting of the following:

    • Kola Nut
    • Yerba Mate
    • Cassia Mimosoides Extract
    • White Willow Bark
  • Tri-Gugglytoid3 Complex (25mg), consisting of the following:

    • Green Tea
    • Guggelsterone
    • Gymneme Sylvestre
  • Caffeine (200mg)

Stacker 2 - Ingredients

While the use of a blend within Stacker 2 does mean less knowledge of exact ingredient dosages when compared to other more transparent options, like Burn XT or Nugenix Thermo, there are still benefits to be had from the inclusion of these ingredients. Below, we will take a more thorough look at what is included in the Stacker 2 formula and the benefits these ingredients may provide.

Proprietary Blend

The first ingredient in Stacker 2 is a proprietary blend that contains a number of plant-based ingredients and herbal extracts. Specifically, this blend contains kola nut, yerba mate, cassia mimosoides, and white willow bark. 

So, what might these ingredients do for you?

Kola Nut

Kola nut, which is the fruit of the Kola tree, is a caffeine-concentrated nut. As you may know, this nut was also used in Coca-Cola and thus had an influence on that product’s name. Research on the kola nut for weight loss is limited, but some evidence shows that it can suppress appetite and lead to more weight loss. 

Yerba Mate

Next up, yerba mate comes from the leaves of the holly tree, and it has quite a bit of caffeine in it. It has been shown to increase energy expenditure and weight loss, and it also may improve glucose and cholesterol levels, all of which play a role in fat and weight loss.

Cassia Mimosoides

The third ingredient in this blend is Cassia mimosoides extract. This shrub contains a few beneficial compounds, but the main one is chrysophanol. Chrysophanol has been shown to inhibit fat accumulation, improve insulin sensitivity, activate brown fat and increase energy consumption, and reduce body weight. Therefore, it may be beneficial for people with obesity and metabolic disorders, though the research has been primarily in animals. 

White Willow Bark

Last in this blend is white willow bark. White willow bark comes from the white willow tree and has been primarily used for its anti-inflammatory and analgesic (pain-killing) effects. This is due to certain compounds such as salicylates, flavonoids, and polyphenols. Despite offering benefits in these areas, there isn’t specific research showing its effectiveness for fat loss. 

Tri-Gugglytoid3 Complex

Another blend in this product is the Tri-Gugglytoid3 Complex, a name that sounds like it’s straight out of a sci-fi movie. Nonetheless, this complex is, in fact, real, and contains three ingredients: green tea, guggulsterone, and Gymnema Sylvestre.

Green Tea

Green tea is an all-around health product, containing polyphenols, gallates, and catechins, among other compounds that benefit health. Green tea extract may also increase metabolism, improve glucose and cholesterol levels, and lead to reductions in BMI and fat mass. Lastly, green tea has a thermogenic effect when paired with caffeine. 


The next “g” ingredient in this complex is guggulsterone. Guggulsterone is a phytosteroid that comes from the guggul plant. Guggulsterone has been used in Ayurveda for thousands of years, and there is some research showing it may lead to increased weight loss and increased fat metabolism. However, the research overall is limited.

Gymnema Sylvestre

Lastly, this complex contains Gymnema Sylvestre, which is a shrub. The leaves of this plant contain a few beneficial compounds, including triterpenes, glycosides, and saponins. It has been shown to reduce blood sugar and lipids (fats), so these improvements may help you to lose weight. 


The final ingredient in Stacker 2 is caffeine in the form of caffeine anhydrous. Caffeine has been used for a long time for fat loss since it stimulates the central nervous system and increases metabolic rate significantly. Caffeine can also reduce appetite, as most stimulants are known to do. Unsurprisingly then, caffeine appears to promote reductions in body weight, fat mass, and BMI. 

Does Stacker 2 Really Work?

So, after analyzing Stacker 2, it is likely that it will work at least somewhat well for fat loss. Most of the ingredients in Stacker 2 are well-researched and shown to be effective for fat loss, either directly or indirectly. Stacker 2 contains a range of ingredients that increase metabolism, suppress appetite, help to regulate blood sugar, cholesterol, and fat metabolism, and increase energy expenditure, all of which should lead to fat loss. 

However, there are some weaknesses to consider. First, some of the ingredients have primarily been researched in animals, such as Cassia mimosoides and Gymnema Sylvestre, so they may not work as well in people. 

Another consideration is that, since this product uses a blend and a complex, it is impossible to tell exactly how much of each ingredient is in the Proprietary Blend and Tri-Gugglytoid3 Complex. So, even though the ingredients in there are known to be beneficial, you might not get as many benefits if the doses aren’t optimal. 

Stacker 2 - On Fire

Claims vs. Reality

Stacker 2 claims it will help you burn fat, boost energy, and lose weight. And overall, these claims are probably true, especially when paired with a healthy diet, exercise, and lifestyle. Nearly all of the ingredients in Stacker 2 have been shown to affect at least one of those areas; the only one not doing so is white willow bark. Stacker 2 contains quite a bit of caffeine, not only from caffeine itself, but also from kola nut, yerba mate. So, this is one of the main reasons for its benefits. But the other herbs and ingredients here, such as the Tri-Gugglytoid3 complex, offer other benefits, including positive effects on metabolism, appetite, and weight reduction. Overall, the ingredients should not only work by themselves, but also may have a synergistic effect on each other.

Who is Stacker 2 Best for?

Stacker 2 is best for anyone wanting to lose fat and improve their overall cardiometabolic health. Granted, it is most effective for people who also are going to exercise, eat healthy, and overall live healthy, as the effects will be the most pronounced if these other things are done. This product is also best for people who like and can handle stimulants since there is a significant amount. If you are sensitive to stimulants, this product is probably not going to be what you want. 

Stacker 2 - Waist measurement

Is Stacker 2 Safe?

There are few things to consider in terms of safety and possible side effects of Stacker 2. Here are the main ones:

  • Due to its high caffeine and stimulant content (caffeine, kola nut, yerba mate) it may produce anxiety, jitters, nervousness, increased heart rate, insomnia, and related issues. This is not for people sensitive to stimulants.
  • Since some of the ingredients may affect blood sugar (e.g., Gymnema Sylvestre), individuals with diabetes should be cautious. 
  • Guggulsterone sometimes produces mild gastrointestinal side effects (e.g., nausea)

Where to Buy Stacker 2

Stacker 2 is available for purchase on Amazon.

Stacker 2 - Buy on Amazon

Each bottle costs $12.89 and contains 100 servings (100 capsules). So, you’re getting a pretty darn good price per serving, much lower than most fat-burners.

Overall Rating:
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Jack Cincotta, MS

Jack Cincotta is a certified holistic health coach through AFPA and a board-certified holistic health practitioner through AADP. He has written hundreds of articles on nutrition and supplementation. Jack has a M.S. degree in Psychology and is passionate about researching the science behind nutrition. He often uses research-backed supplementation protocols for many of his clients to optimize results.

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