Updated: 01/11/2018

Why is it that so few diet products are backed by science? Let’s find out if GNC Mega Men Energy and Metabolism is one of the good ones. There are people interested in this supplement, so we examined the ingredients, side effects, clinical research and quality of customer support. Additionally, we picked apart hundreds of consumer reviews and comments. We then refined and summarized to give you the info you need.

GNC Mega Men Energy And Metabolism Readers: Click here to find out why we're giving away samples of our product, Burn HD.

What is GNC Mega Men Energy and Metabolism?

First off, GNC Mega Men Energy and Metabolism is a “calorie-burning” multivitamin. The ingredients are caffeine, capsicum seed extract [1], black pepper extract, green tea extract [2], amino acids and B-vitamins [3]. The recommended serving is two capsules daily, which supposedly promotes weight-loss and increases metabolism. One of the benefits is the availability of the supplement.

There’s no information as to when the company first introduced GNC Mega Men Energy and Metabolism, but it  was founded in 1935. It doesn’t appear the supplement contains artificial ingredients, a good start. We do like the amount of time the business has been in operation and the favorable BBB rating, but read on…

Products Similar to GNC Mega Men Energy And Metabolism

GNC Mega Men Sportread
Advocare Sparkread
Focus Factorread
Burn HD (Sample offer)read

GNC Mega Men Energy and Metabolism Side Effects – “Concerning?”

The first negative aspect deals with GNC Mega Men Energy and Metabolism side effects. “When you take a multivitamin, it’s to support overall health and wellness,” said our Research Editor. “What you don’t expect are adverse reactions.”

“My body temp elevates, I feel jittery, light headed and my stomach acts up,” said a user.

“I cut ALL sources of caffeine out of my diet when I started taking this, and within just a couple days I was having feelings of my heart racing, shortness of breath, and my stomach was freaking out,” reported a customer.

Some reports of side effects may be associated with stopping the vitamin, for some, according to a review.

The user claimed, “I read that some users had headaches when they stopped taking it.. I have gone on week long trips and left these vitamins at home and have never experienced any type of side effect.”

GNC Mega Men Energy And Metabolism Customer Testimonials

Regulatory Issues

The New York Attorney General’s office contacted the parent company in March of 2015 relating to the mislabeling of products [4]. The ruling stated several supplements didn’t contain ingredients listed on the packaging.

Ineffectiveness – “Another Issue”

Based upon numerous customer comments, GNC Mega Men Energy and Metabolism ingredients don’t live up to the hype. “I’ve never felt an upswing of energy from these. I’m a bigger guy (6’6″, 305) and consistently in the gym lifting weights. Even with an upped dosage I still don’t feel anything,” said a consumer.

“I tried this product for three weeks, I’m still taking it. Didn’t work for me, feel the same no increase energy,” commented a dieter.

On the other side, users see results.

One review said, “Since I’ve started taking these supplements I’ve had more stamina in sports, felt more energized later into the day, and felt better and more healthy as a whole.”

Another shared, “Even if this is all just a placebo effect.. it worked for me and that vitamin portion is still real.”

Based upon our research, if any part of a supplement is concerning, like not producing results, it could put a damper on long-term success. If GNC Mega Men Energy and Metabolism doesn’t help you lose weight, you’ll look for something better.

The Science – “Clinically Proven?”

According to the official website, GNC Mega Man vitamins are “clinically studied”. We notice it contains a few proven ingredients [5] [6], but the link between those and this formula isn’t there. Also, there’s no published scientific research supporting the weight-loss claims. At DietSpotlight, finding solid science is critical to the review process. If science-based facts aren’t there, we see a bigger issue.

What Users Are Saying

“Have been taking this product on and off for about three years and unlike the average multivitamins this product delivers exactly what my body needs to function to its optimal levels.”

“I definitely can feel a difference in my energy levels. The only downside, they have 100mg of caffeine per pill. Yikes!”

“Did nothing.”

Also: read our Burn HD Weight-Loss Kit review »GNC Mega Men Energy And Metabolism Ingredients

The Bottom Line – Does GNC Mega Men Energy and Metabolism Work?

Are you racing out to buy GNC Mega Man vitamins? Well, we like the low price and that we found a few positive comments, but we are skeptical about this one because the weight-loss claims are not supported by published clinical research. Plus, we’re concerned about it not working and customer reports of negative side effects.

If you’d like to lose that extra weight, we suggest going with a supplement not linked to harmful side effects and containing ingredients shown to help with weight-loss.

Among the best products we’ve seen this year is one called Burn HD. The four clinically-tested ingredients have been shown to help accelerate metabolism, boost fat loss and reduce appetite. There’s no one talking about harmful side effects and the chatter online is about people seeing excellent results.

The company responsible for Burn HD is so confident in the supplement, they’re offering a 2-Week Sample, a nice bonus.

Learn More About Burn HD »
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GNC Mega Men Energy And Metabolism

What are the side effects of GNC multivitamin?

Possible GNC Mega Men Energy and Metabolism side effects may include nausea, stomachache, diarrhea and headache. This is according to customer reviews.

What are the ingredients in GNC Mega Men Energy and Metabolism?

GNC Mega Men Energy and Metabolism ingredients are caffeine anhydrous, black pepper, capsicum seed, l-carnitine, taurine, l-methionine, l-glutamine, green tea, choline, inositol, alpha-lipoic acid, vanadium, astaxanthin, lycopene, zeaxanthin, lutemax 2020 lutein, boron, molybdenum, chromium, manganese, copper, selenium, zinc, magnesium, iodine, vitamin A, calcium, vitamin C, pantothenic acid, vitamin K, biotin, folic acid, vitamin D, niacin, vitamin B12, riboflavin, vitamin B6, vitamin E, thiamin and silica.

How do I know if GNC Mega Men Energy And Metabolism is right for me?

Choosing the right product is the #1 question asked by DietSpotlight readers. We recommend trying any product before buying it and know that finding a product with a sample offer is near impossible - so we created our own product, Burn HD, with scientifically backed ingredients.

Click here to get your sample of our powerful fat burner today.

Does GNC Mega Men Energy and Metabolism work?

GNC Mega Men Energy and Metabolism contains green tea and caffeine; both shown to boost metabolism . These ingredients have been clinically-tested and may help with weight-loss, but the benefits of the two are not linked to this product.

How much does GNC multivitamin cost?

The cost of GNC Mega Men Energy and Metabolism is $49.99. However, the member price is $44.99.

How should I take GNC Mega Men Energy and Metabolism?

The directions say to take one packet daily with food. A box will last for 30 days.

Can women use GNC Mega Men Energy and Metabolism?

Yes, but it’s not recommended. This product is formulated for men.

Is there an age cut-off for GNC Mega Men vitamins?

No, as long as you are 18 or older, you can take this product.

GNC Mega Men Energy And Metabolism Ingredients

GNC multivitamin, or mega man vitamins, is essentially a multivitamin with a few extra ingredients to boost metabolism and support energy. The label says "Clinically Studied" but that's true of all multivitamins.

GNC Mega Men Energy And Metabolism Ingredients and Supplement Facts

Serving Size: 2 Caplets
Serving Per Container: 90
Amount per Serving% DV
Energy and Metabolism Blend150mg*
- Caffeine Anhydrous**
- Green Tea Extract**
- Eleuthero Root Extract**
- Capsimax Capsicum Seed Extract**
- Black Pepper Fruit Extract**
Super Antioxidant Blend**
- Alpha-Lipoic Acid25mg*
- Lutemax 2020 Lutein2mg*
- Lycopene1mg*
- Turmeric Root Extract500mcg*
- Zeaxanthin400mcg*
- Astaxanthin50mcg*
- Beta-Cryptoxanthin10mcg*

Other Ingredients: Cellulose, stearic acid vegetable source, magnesium stearate vegetable source, titanium dioxide, natural vanilla mint flavor, talc, caramel color, stevia leaf extract

We dug deep into the GNC Mega Man vitamins ingredients to give you the crucial details you need.

Caffeine Anhydrous

Caffeine is a stimulant and mild diuretic. It comes from natural sources such as tea leaves, coffee beans, kola nut, guarana and yerba mate plants. Anhydrous is simply a dry or powder version, which is often found in diet supplements, energy pills and weight-loss products.

What is it Supposed to Do?

Usually caffeine anhydrous is added to diet supplements as a stimulant. It’s intended to boost metabolism, reduce appetite, enhance focus and improve athletic performance or energy levels.

Clinical Research

“Caffeine may stimulate thermogenesis — one way your body generates heat and energy from digesting food,” says the Mayo Clinic [1].

Green Tea Extract

Green tea is also known as camellia sinensis. Unlike black and oolong varieties, this tea is unfermented. It’s consumed in several parts of Asia as a health beverage, and is also found in numerous diet supplements for weight-loss.

What is it Supposed to Do?

Green tea contains catechins (antioxidants) and caffeine (a stimulant). These components work together to boost metabolism, improve immune system and heart health, elevate energy levels and promote fat loss.

Clinical Research

WebMD states that, “Green tea has been shown to improve blood flow and lower cholesterol. A 2013 review of many studies found green tea helped prevent a range of heart-related issues, from high blood pressure to congestive heart failure.”

Eleuthero Root Powder

More commonly known as Siberian ginseng, eleuthero root is a plant that’s native to regions like Russia. It has been used for centuries to make medicine to treat cold and flu symptoms, mental fatigue, diabetes, bronchitis and high blood pressure.

What is it Supposed to Do?

Typically eleuthero root is added to diet supplements to help lower stress levels, boost immune system health, and improve mental and physical performance. This in turn may aid with weight reduction.

Clinical Research

According to the University of Maryland Medical Center, “Siberian ginseng is often said to improve athletic performance and increase muscle strength. While some studies have found positive results, others have found that Siberian ginseng had no effect.” [2]

One that we’ve been keeping our eye on is one called Special Trial Offer. It contains clinically-tested ingredients and is backed by positive customer reviews. Want to learn more? Click above.

GNC Mega Men Energy And Metabolism Scientific Abstracts


There was less weight gain linked with an increase in tea and coffee intake. In men, the link between caffeine consumption and weight was more significant in young subjects (P for interaction < 0.001); with women the link was more significant in those who had a BMI (body mass index) (in kg/m2) ≥25, who were shown to be less physically active or who had smoked (P for interaction < 0.001). [1]

Green Tea Extract

The green tea extract was found to elevate high-density lipoprotein cholesterol. HOMA-IR index reduced from 5.4±3.9 to 3.5±2.0 in only the therapeutic arm. Apolipoprotein A1, Apolipoprotein B100, and adiponectin were found to elevate substantially in both arms. However, the therapeutic arm experienced an increase of just glucagon-like peptide 1. The only noticeable pattern was a reduction of triglyceride seen in between-group comparison. This study indicates that green tea extract greatly enhances insulin resistance and elevates glucagon-like peptide one exclusively in group-comparison. Potential activities of green tea on insulin resistance as well as glucagon-like peptide 1 present a good case for further investigation. [2]

Alpha-Lipoic Acid

In vitro and laboratory animal experiment results have shown that Alpha-Lipoic Acid controls the cell apoptosis of a variety of different cancers via an elevation of reactive oxygen species, and reduction of cell growth. Furthermore, the results have shown that Alpha-Lipoic Acid harnesses antioxidant traits along with the ability to resurrect other antioxidants, which plays an important part in the treatment of central sensitization diseases. Alpha-Lipoic Acid is a vital antioxidant and prooxidant force in the treatment of cancer and central sensitization diseases. There need to be more extensive studies carried out to determine clinical importance in humans. [3]


The lycopene group (P < 0.0001) experienced plasma lycopene concentration elevation, but had no effect on other plasma carotenoids. The placebo group experienced a progression of prostate enlargement which was examined by transrectal ultrasonography (P < 0.05) as well as a digital rectal exam (P < 0.01). Prostate showed no signs of enlarging in the lycopene group. The IPSS questionnaire was used to examine symptoms of the disease and found a significant improvement in both groups with a greater effect in the male participants who took lycopene supplements. It was concluded that lycopene did indeed block progression of benign prostate hyperplasia. [4]


Choline tablets were given to players in the experimental group for a week prior to a competition. Results indicated some substantial alterations between pre-competition and post-competition measurements of free plasma choline, leptin, urine malondialdehyde, and urine choline levels. Post-competition measurements also displayed a decrease in body mass. It was concluded that choline supplementation might quickly decrease body mass with no adverse side effects on static strength or biochemical levels. [5]


Previous GNC Mega Men Energy And Metabolism Review (Updated October 3, 2014):

What You Should Know about GNC Mega Men Energy and Metabolism

GNC Mega Men Energy & Metabolism attempts to combine a healthy multivitamin with an energy booster. Its female equivalent is GNC Women’s Ultra Mega Energy And Metabolism. There are plenty of supplements out there that make this attempt, but most fail because there is either too much or too little caffeine. Caffeine is the primary, cheap ingredient to boost energy and it's effective at increasing metabolism, but it's not the only proven ingredient. This is made evident because similar products, like Man Scorch Fat Burner, utilize this ingredient. We found this supplement listed on GNC for $19.99; cheaper than other premium multivitamins.

List of Ingredients


  • Magnesium
  • Zinc
  • Selenium
  • Copper
  • Manganese
  • Chromium
  • Molybdenum
  • Vitamin A
  • Vitamin C
  • Vitamin D
  • Vitamin E
  • Vitamin K
  • Thiamin
  • Riboflavin
  • Niacin
  • Vitamin B6
  • Folic Acid
  • Vitamin B12
  • Biotin
  • Pantothenic Acid
  • Iodine
  • Green Tea Extract
  • Alpha-Lipoic Acid
  • Choline
  • Inositol
  • Silica
  • Boron
  • Lutein
  • Lycopene
  • Zeaxanthin
  • Astaxanthin
  • Vanadium

Energy and Metabolism Blend:

  • Black Pepper Extract
  • Caffeine Anhydrous
  • Capsimax Capsicum Seed Extract

Proprietary Amino Acid Blend:

  • L-Taurine
  • L-Methionine
  • L-Glutamine
  • L-Carnitine

Product Features

The majority of the ingredients in GNC Mega Man vitamins and minerals. These have no direct impact on metabolism or energy, but they do support healthy functions in the body that may impact both. What does take a direct effect on the metabolism is alpha lipoic acid found in this supplement, best known as a fatty acid as well as a natural antioxidant that helps with converting glucose into energy and is very involved in energy metabolism. You can find at your local produce store some fruits and vegetables that contain the fatty acid, some include: spinach, broccoli, tomato and green pea. Although other products containing the same ingredients boast the some claims to increase weight loss like with Purple Tiger Energy.

Then we hit the proprietary blends. One of the proprietary blends contains four amino acids. There are healthy functions for amino acids, but they are not effective at increasing metabolism or energy.

The ingredients that work to increase metabolism in this supplement are caffeine and green tea.

The caffeine is included in a proprietary blend with just short of 120 mg. That means there is not likely enough caffeine to increase energy or metabolism. There is only 40 mg of green tea extract - so metabolism support from the green tea is out of the question.

According to clinical studies, about 300 mg of green tea is required to boost weight loss. While we realize this supplement does not claim to boost weight loss directly, that is the implication when the product name claims metabolism support. Just 40 mg of green tea and less than 75 mg of caffeine is not enough to have any impact. Many products have secondary effects, like how Man Vaporize could possibly aid in kidney health.

Advantages of GNC Mega Men Energy and Metabolism

  • All ingredients are listed online.
  • The supplement contains green tea and caffeine.
  • A good source of vitamins.
  • Sells for less than most premium supplements.

Disadvantages of GNC Mega Men Energy and Metabolism

  • Does not contain enough green tea.
  • Does not contain enough caffeine.
  • Will not support metabolism.

Conclusion on GNC Multivitamin

GNC Mega Men Energy & Metabolism is supposed to support a healthy metabolism and energy level. The ingredient list contains all the ingredients we expected, but it does not contain enough of either proven ingredient to have an impact on energy or metabolism. GNC Mega Men Sport is a more athletic version though not much different. This supplement is nothing more than a great multivitamin.

Summer Banks Dietspotlight Author
About the Author:

Summer Banks, Director of Content at Dietspotlight, has researched over 5000 weight-loss programs, pills, shakes and diet plans. Previously, she managed 15 supplement brands, worked with doctors specializing in weight loss and completed coursework in nutrition at Stanford University. full bio.

23 GNC Mega Men Energy And Metabolism Reviews

  • Joe

    I just bought Mega Men Energy And Metabolism. How should I take the 6 pills?

    • Jason

      By mouth

  • David

    For those who take these supplement I read the directions and it says two pills a day how do you guys take I mean in time frame. DO you take both in the morning or spread them out the day?

  • bad effects
    Rollin (Verified User)

    I’m trying these out I’m really not Into taking pills and stuff like that just wondering if there good or have any bad effects?

    • Maribel (Editor)

      Hello Rollin. The most common side effects may include nausea, stomachache, diarrhea and headache. This is according to customer reviews. If this concerns you, might want to review Dietspotlight Burn, found no mention of serious side-effects.

  • isaac essuman

    I just bought a box of 30 Sachs each containing 6 cupsules, can I take all?

  • Francisco

    Can these cause insomnia?

    • Anna (Editor)

      Hi Francisco. All users are different and can experience different effects; if you begin to have insomnia, consult with your physician before continuing with this product.

  • when i will take the best results

    I would like to know is it a time release product, and if so when should I take it for best results?

    • Your Name

      This product is excellent. I am chef and i used to work 7 days a week on cruise ships, trust me, these supplements kept me energized all day and i would sleep soundly at night. They also keep you mentally alert. In my job i would start to get tired around 3pm but when i take 2 of these pills (anytime before midday but not too early) i would be happy and enthusiastic all day. 3 years now and no side effects- never felt better.

  • scott

    I just finished emailing back and forth over the fact that GNC just drastically changed this product recently. They have removed insitol, carnitine, taurine, methionine and glutimine. They added tumeric root extract and eleuthero root powder. When i opened a container that i just purchased due to running out. I noticed a huge difference in the caplet size. I went to my kitchen trash can and pulled out the old container. The old container is much larger. I asked why GNC changed the product and I asked what they removed to make the caplet smaller. As you can imagine I haven got a direct answer. To paraphrase i was told that the product was improved based on what their customers wanted. LOL! The biggest thing to me was they are charging the same price after removing ingredients. The expiration dates caught my eye too. The old version of this product was dated 5/18 and the new one was dated 9/18? So what happened in 4 months time? Was the old product dangerous? Was it ineffective? Why didnt they let their customers know they changed the product? GNC didnt offer a decent explanation. They basicly said if you aren’t satisfied get your money back.

  • Ed,

    I’ve been taking the GNC Mega Men Energy And Metabolism for about 1 year and was fine until they changed it up, pills are smaller and doesn’t work as well .

    • Maribel (Editor)

      Oh no, that’s not good. Since you’re dissatisfied with their change, perhaps you could sample Dietspotlight Burn and see if it works better for you.

  • Kevin

    I’ve been taking this for about a week now. I did not buy it for weight loss specifically. I was looking for a multivitamin to get me through the day without the afternoon drag. I also have been losing weight, and was hoping this would assist with those last few hard to shed pounds. I have not had any of the side affects mentioned here. The only thing out of the ordinary was my body getting used to the extra B2. The first couple days my urine was neon yellow. But now it seems my body is metabolising it better, as this has passed. I’d say the vitamin does exactly what it claims. I have all day energy and have noticed my metabolism ramping up, which is great!

  • Your Name JOHN ISHAK

    Hi im from Ontario Canada I just bought a box of 90 capsules, $ 33.00, to day October the 11th, 2016 I have been taken my third pill, So Far so Good, I am Living the Dream. Feel Lots Energy, Not Sleepy. Let’s cross our fingers and experience referent. Regards John Ishak

  • Scotty

    I’ve been taking this plan for about a month. This morning for the second time I’ve experienced flushing and a rash that starts at my face/head and then moves down my neck and arms. Not a great feeling that comes on suddenly. I’ve been trying to keep this to almost an every other day regimen; but have been mostly happy with results.

  • Boogie man

    I notice the difference between Mega Men Sport and Mega Men Energy Metabolism. Energy does speed up you metabolism and I’ve managed to lose a free pounds and keep it off. On the negative side it does speed your heart rate up and make you feel jittery. It doesn’t happen everyday. Mega Men Sport is food for recovery and keeping muscle on.

  • Steve

    GNC Mega Men Energy And Metabolism is giving me a lot of energy, but I am bloated and gaining weight. I like the increased energy but, I do not like the feeling of being bloated, putting on added weight, and fighting additional chronic pain after I do too much daily.

    • Bobby

      Steve is absolutely correct, the weight gain is unbelievable but the energy is great not worth the time if you’re trying to lose weight great energy but I don’t need the weight gain

  • Bob

    I have been using Mega Men Energy and Metabolism for 6 weeks now – I have lost 12-14 lbs but I am also using twice daily apple cider vinegar and lemon juice (1 tbsp. each) mixed in 8 oz of water……………….with E&M I HAVE felt like my body temp rises but also I have more energy and am slimmer as well with the weight loss.

  •  Tried Different Items This Works
    anthony (Verified User)

    I’ve tried different vitamins , I realized that this one works for me.

  • Jerry

    Good products no complaints

    • kevin

      I love this product and having been using it for 3 years. It gives you two energy boosts usually around 3to 4 hours after poppin the pill. The energy boost make me feel near super human but they last around an hour or so. I think in conjunction with a proper diet this is the perfect product.