Stacker 2 is a weight loss aid manufactured by N.V.E. Pharmaceuticals; the manufacturers used to include Ephedra in the original formula, but were forced to remove the ingredient and reformulate after Ephedra was banned and the FDA had to step in.

Below we take an in-depth look at Stacker 2 to see whether it can aid weight loss by burning fat, cutting cravings and boosting the metabolism, as claimed by the manufacturers.

Stacker2 Pros

  • No longer includes the banned substance Ephedra

Stacker2 Cons

  • No money back guarantee
  • Over-relies upon the use of caffeine
  • Unlikely to suppress appetite as claimed
Watchdog Rejected Muscle Pills



What You Need To Know About Stacker2

We are not very impressed by Stacker 2 and its manufacturers, N.V.E. Pharmaceuticals Inc. The company have a fairly poor reputation because of their conflicts with the FDA in the past. We have also reviewed other supplements that are manufactured by N.V.E. Pharmaceuticals, and we were unimpressed by those products as well.

The list of restrictions for this product is extensive. There is no money back guarantee offered, and the returns period offered by the manufacturer’s website is ridiculously short, as it is calculated from the original purchase date, not from the date of delivery. The product contains a high dose of caffeine, and so if customers are taking several capsules per day, as recommended, then they are much more likely to develop side effects. Taking large amounts of caffeine regularly can also lead to the consumer developing withdrawal symptoms once they stop using the product; this has been reported by some reviewers of Stacker 2.

What Are The Side Effects Of Stacker2?

It appears that the ingredients used in Stacker 2 can cause a range of side effects, some of which appear to be fairly common. For a full list, please see below.

How Much Does Stacker2 Cost?

A 4 capsule blister pack costs $1.49 plus delivery charges. A 20 capsule bottle costs $5.65, and a 100 capsule bottle costs $19.99.

Our Verdict On Stacker2

We believe that this supplement could potentially aid a very small amount of weight loss, but that it is unlikely to suppress the consumer’s appetite, as claimed. The formula used in Stacker 2 over-relies upon the use of caffeine. Although caffeine, yerba mate and green tea all have clinical support linking them with an increased calorie burn from a boosted metabolism and increased levels of thermogenesis, the beneficial weight loss effects are not very dramatic. There is also no money-back guarantee.

We do not recommend Stacker 2 to our readers.

Stacker2 Review

According to the manufacturers, Stacker 2 is a fat burning, metabolism boosting weight loss supplement that also acts as an appetite suppressant.

Stacker2 Facts

  • Manufactured by N.V.E. Pharmaceuticals
  • Forced to remove Ephedra after it was banned

Stacker 2 is manufactured by N.V.E Pharmaceuticals Inc, a company based in New Jersey. Our research has uncovered several concerns about this product and the manufacturing company. N.V.E. Pharmaceuticals Inc have been in trouble with the FDA back in 2013 after their manufacturing facility and procedures were found to be in “serious” violation of the Current Good Manufacturing Practice (CGMP) regulation for Dietary Supplements. The owner of the company, Robert Occhifinto was one of the supplement manufacturers who fought the ephedra ban in 2004, claiming that the FDA were unable to prove that the ingredient was dangerous when used as directed (despite 16,000 adverse-event reports and a government-commissioned study that linked the adrenaline-like stimulant to heart attack, stroke and death).

How to Take Stacker2

Take one capsule after meals. Do not exceed 3 capsules in a 24 hour period.

N.V.E. Pharmaceuticals can be contacted using the information found on their official sales website.

Stacker2 Concerns:

  • No money back guarantee
  • Over-relies upon the use of caffeine
  • Unlikely to suppress appetite as claimed

What Does Stacker2 Claim To Do?

According to the manufacturers,

The Stacker 2 formula is designed for those who are in search of a dietary supplement in a powerful Ephedra-free formula. This formula when taken as directed may help burn fat, cut cravings and boost a sluggish system without the use of ephedra.

Does Stacker2 Work?

When trying to establish whether a product will actually work, we look at the ingredients used, the quantities that they are used in, and also turn to customer reviews, to see how the product works in practice.

There are lots of reports of side effects from consumers, which primarily appear to be caffeine-related. Insomnia is common, and seems to be made worse by the manufacturer’s directions for use; by instructing consumers to take each serving after a meal, it is likely that the final capsule will be taken relatively late in the evening, making insomnia much more likely. By taking the capsule earlier in the afternoon, or only taking two and skipping a third dose, consumers are much less likely to develop side effects.

Whilst caffeine has been linked with an increase in the body’s metabolic rate, the actual weight loss caused by caffeine consumption appears to be ‘small but significant’. The dosages of the other ingredients are unknown as they are a part of a proprietary formula, but we suspect that the doses of green tea and yerba mate are less than the amounts used in successful clinical trials, making it less effective overall.

Stacker 2 appears to be good at boosting energy levels, but we suspect that consumers will not lose significant amounts of weight whilst using the supplement, as the product heavily relies on its high caffeine content. Many consumers are disappointed with this product, especially in comparison to the older formulations of Stacker 2, which contained the now-banned ingredients Ephedra.

What Are The Ingredients of Stacker2?

The ingredients used in Stacker 2 are detailed below. The majority of the ingredients are a part of a proprietary formula, and so their individual ingredient quantities are not provided. Each capsule contains 267 mg of the proprietary formula, and an additional 200 mg of caffeine.

Proprietary blend 267mg

  • Yerba mate (leaves): There is diverse clinical evidence to support the use of this plant for weight loss, as it stimulates the central nervous system and increases the metabolic rate. It is also a source of caffeine, and so should increase energy levels. Read our full investigation for more information.
  • Camellia sinensis 60% polyphenols (green tea leaves): Green tea is high in a group of antioxidants called catechins. Studies have suggested that catechins increase thermogenesis in the body, whilst caffeine increases energy expenditure by boosting the metabolism slightly for few hours.
  • Guggulsterone (whole plant): Guggul extract is taken from the sap of a tree native to India. Currently, evidence that Guggul is useful for weight loss is preliminary, with mixed results from the few trials already conducted upon it, with some suggesting that Guggul has no effect upon weight loss, whilst others suggest its effect is moderate.
  • Cassia mimosoides extract (leaves/stems/pods): this plant appears to act as a diuretic and laxative, and may be a natural mosquito repellent. It is thought to act as a lipase inhibitor, preventing the absorption of fat in the stomach and intestines, with the undigested fat being excreted. This could aid weight loss in some people, theoretically, but there is seemingly no clear evidence that
  • White willow bark: Willow bark contains salicin, which acts a painkiller, and is thought to be as effective as aspirin. There is some evidence that when taken in conjunction with kola nut and ephedra, it can cause weight loss. It does not seem to have been tested on its own for weight loss properties.
  • Caffeine 200mg: Numerous studies have shown that caffeine boosts energy levels and alertness, as well as mildly boosting the metabolism. The effects shown in studies are small, and some studies are inconclusive.

Does Stacker2 Have Any Side Effects?

It appears that the ingredients used in Stacker 2 can cause a range of side effects, some of which appear to be fairly common.

Yerba mate and green tea are both natural sources of caffeine used in this diet pill, as well as caffeine being used as a separate ingredient. Caffeine can cause headaches, increased urination, jitteriness, dehydration, increased heart rate, increased blood pressure, heart palpitations and problems sleeping. Green tea can also cause constipation.

With consumers being instructed to take up to 3 capsules per day, they are consuming at least 600 mg of caffeine each day, not including any unseen caffeine content in the yerba mate and green tea. Consumers should avoid all other sources of caffeine, such as tea, coffee and soft drinks or energy drinks, as the dose of caffeine found in Stacker 2 is highly likely to cause some side effects on its own, and other sources of caffeine would likely cause more side effects.

Guggulsterones can cause side effects, including stomach upset, headaches, nausea, vomiting, loose stools, diarrhoea, belching, and hiccups. Guggul can also cause allergic reactions such as rash and itching. Guggul can also cause skin rash and itching that is not related to allergy.

Cassia mimosoides appears to work as a mild diuretic and laxative. Dehydration is the main worry here, as severe dehydration can cause a range of serious secondary side effects. Drink plenty of water whilst taking this supplement, and stop taking the supplement if you develop diarrhoea.

White willow bark contains salicin, which is closely related to the active ingredient in aspirin. This means that it is not suitable for anyone who is allergic to aspirin. It can cause stomach upset, digestive system upset, rash, itching, and other symptoms of an allergic reaction.

Not suitable for anyone under the age of 18. Do not use if you are pregnant or nursing individuals who consume caffeine with this product may experience serious adverse health effects. Individuals who are sensitive to the effects of caffeine should consult a licensed health care professional before consuming this product. Avoid all other sources of caffeine whilst taking this supplement. In case of accidental overdose, seek professional assistance or contact a poison control center immediately. Avoid alcohol while taking this product. Do not exceed recommended serving. Exceeding recommended serving may cause serious adverse health effects, including heart attack and stroke. Discontinue use and call a physician or licensed qualified health care professional immediately if you experience rapid heartbeat, dizziness, severe headache, shortness of breath, or other similar symptoms. Improper use of this product may be hazardous to a person’s health. Exceeding recommended serving will not improve results.

Are There Any Customer Reviews For Stacker2?

There are numerous customer reviews for Stacker 2 on amazon, one of the third party online retailers that stocks the supplement.

Good product.. of course it does not have the same affect as when it had that special ingredient in it. Still has good ingredients though. One is a cancer fighter, one helps to lower cholesterol and sugar, another ingredient is an anti-inflammatory and the remaining is for energy. So not a bad product at all.

Over the years, I’ve used some of these and some of those. Some of this and some of that, so to speak. Some are not enough and some are just too much, but Stacker 2 caps are just right. They work just enough to give off the right amount of energy to keep going without feeling jittery.

I used to take these a while ago and I remembered they gave me a decent amount of energy throughout the day. I tried them again but they didn’t really do much for me, nor did they help me lose any weight. They did give me a bit of an energy boost, but not like they used to. I would recommend these to people looking for a bit of an energy booster, but I wouldn’t rely on them for weight loss. Of course, weight loss pills must be paired with a healthy diet and exercise, but I feel there are better weight loss pills out there.

Garbage. I was looking for something to add some energy to my workout. I don’t see how they could be fake, but they seemed to actually make me more sluggish. Perhaps it’s just my personal bodily chemistry or whatever. The Staker 3 XPLC without the crazy hypothetical fat-blocker worked great the first try yesterday.

i just had a baby so ive been working towards my prebaby body. I got the stacker 2 for the energy, not really the weight loss supplement, for a boost in my workout. First off, there was absolutely no added energy. When i say none, i mean zero difference. I dont drink coffee and stopped drinking soda like a month ago to help my efforts in weight loss and still, nothing. Secondly, no weight loss. Although i read it doesnt really work for weight loss anyway. The final and most contributing factor is the side effects. It took me hours to fall asleep, i never got a good nights sleep taking it and therefore i suffered from exhaustion and fatigue. And what symptoms go hand in hand with fatigue? Irritability and sadness. The worst things to deal with when caring for a new baby. I took the pills for two weeks before i decided to stop them. Since, after dealing with sudden and intense headaches from the caffeine withdrawal im back to my happy go lucky self. In the case of stacker 2 ephedra free, the benefits do not outweigh the risks.

Does Stacker2 Offer a Money-Back Guarantee?

There is no money back guarantee for Stacker 2. Customers who ordered through have 14 days from the purchase date to return unwanted products, provided that they are unopened and the customer has first obtained a returns authorisation number, and written it on the outside of the package.

Where Can I Buy Stacker2?

Stacker 2 is available from As this appears to have been the first product in N.V.E Pharmaceutical’s range, the website is named after the product, but the company sell a huge range of other weight loss supplements.
They sell Stacker 2 in three sizes on the official website; a 4 capsule blister pack costs $1.49 plus delivery charges.

A 20 capsule bottle costs $5.65, and a 100 capsule bottle costs $19.99. Delivery charges may apply.

The supplement is also available from amazon. A bottle containing 100 capsules costs $17.99 with free shipping. They also offer a 5% discount for customers who sign up to ‘subscribe and save’ where the product is auto-shipped out to the customer over regular intervals (usually monthly).

Another amazon seller is offering two packs of 20 capsules together (40 capsules total) for $7.74 plus delivery charges.

Summary: Stacker2

Image not available at this time

1.9 out of 5
Editor's Rating
  • Effectiveness
  • Safety
  • Price / Guarantee

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Disclaimer: Our reviews and investigations are based on extensive research from the information publicly available to us and consumers at the time of first publishing the post. Information is based on our personal opinion and whilst we endeavour to ensure information is up-to-date, manufacturers do from time to time change their products and future research may disagree with our findings. If you feel any of the information is inaccurate, please contact us and we will review the information provided.

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