Metabolic Nutrition claims its diet pill, Synedrex, is “the most powerful and effective ONE DOSE DAILY weight loss solution ever developed.” Metabolic Nutrition also promises Synedrex boosts metabolism, maximizes energy, and suppresses appetite.

Is Synedrex really the amazing diet pill its manufacturers claim it to be? I researched the company and the product to find out.

Who Makes Synedrex?

Metabolic Nutrition Inc. is a health supplement company headquartered in Tamarac, FL. Not much is known about Metabolic Nutrition and the company doesn’t provide any information about itself on its website.

Metabolic Nutrition Inc. is not accredited by the Better Business Bureau (BBB). It currently has a low score of “F” on a scale of A+ to F with the BBB.[1]

A poor BBB rating and lack of information on a business doesn’t mean the business is shady or its products are bad. However, it doesn’t inspire confidence in the company and its products.

What’s in Synedrex?

Synedrex contains 16 ingredients; 12 are listed as a proprietary blend. The following are the 7 most prevalent ingredients in Synedrex’s formula:Synedrex

Vitamin B3 (Niacin) (20 mg)
Vitamin B3 facilitates the conversion of carbohydrates into glucose, which the body uses as energy.[2] While the ingredient supports a healthy metabolism, there is no clinical evidence linking it to weight loss.

However, vitamin B3 promotes better blood circulation which may improve athletic performance by delivering oxygen to muscles tissue quicker.[3]

Vitamin B12 (100 mcg)
As a B vitamin, this ingredient promotes energy metabolism and is said to improve performance. However, clinical evidence does not back this use. In fact, researchers found vitamin B12 does not enhance performance for most people.[4]

Chromium (175 mcg)
Chromium prevents glucose intolerance.[5] This allows more efficient carbohydrate processing and fat burn.

Proprietary Blend (815 mg)

Methylxanthine is a diuretic, promoting water excretion.[6] However, methylxanthine is a relatively weak diuretic. Because Methylxanthine is part of a proprietary blend, it’s difficult to tell if there is enough in Synedrex to significantly increase water loss.

Methylxanthine also stimulates the heart.[7]

A 2011 clinical study shows 50 mg of synephrine boosts metabolism but doesn’t raise heart rate or blood pressure when used in correct dosages.[8]

Green Tea Extract
Green tea extract provides strong antioxidants and promotes fat burn.[9] It is also commonly used to suppress appetite.

Sulbutiamine is a synthetic thiamine derivative. The ingredient treats asthenia and other weakness-based conditions by improving muscle strength and endurance.[10]

It may also stimulate cognitive functions, such as memory, in animals.[11]

Synedrex’s ingredients are a mixed bag. On one hand, Synedrex provides proven ingredients such as synephrine. On the other hand, many ingredients are listed in a blend, making their actual effectiveness questionable.

User Reviews

According to most users, Synedrex is effective. On, Synedrex enjoys a respectable score of 4 out of 5 stars from 43 user reviews. According to users, it suppresses appetite and gives energy. The following is a sample of what recent users say about Synedrex:

Demanda1 shared, “This produce gave me energy all day and decreased my appetite.”

Alexa admitted, “So, I was very hesitant of starting this supplement because I was aware of all the fake reviews about how great it was. I finally decided I would take a chance and be very careful with it. Definitely causes the jitters.”

Chris Ace liked the weight loss that he saw with Synedrex, but like Alexa, he suffered various side effects. Chris stated the product caused “nausea, vomiting, vertigo, muscle spasms, palpitations.”

Most users felt Synedrex curbs appetite, promotes fat burn, and increases energy. However, there were many complaints regarding side effects.

Are There Side Effects?

Like Chris, many Synedrex users suffer side effects ranging from nausea and jitteriness to muscle cramping and heart palpitations. Many of these side effects could be caused by the various stimulants found in Synedrex.

Of particular concern is 1,3 Dimethylamylamine (DMAA). DMAA is known to cause high blood pressure and even heart attacks or strokes. It is a stimulant linked to the death of two soldiers. Consequently, the FDA recently banned DMAA, and countries like New Zealand have banned it altogether.[12]

Though DMAA-containing supplements can still be purchased online, the FDA warns consumers not to purchase and use them as serious side effects can occur.[13]

How Do You Use It?

Start by taking 1 capsule in the morning when you wake up and then another capsule 4 to 6 hours later.

Once tolerance is established, you may increase the dosage to 2 capsules twice a day.
Do not exceed 4 capsules daily.

Also, due to the various stimulants in the product, do not take Synedrex within 6 hours of bedtime.

How Much Does It Cost?

Synedrex can be purchased online from various vendors. For example, sells one bottle (45 capsules) for $40.13 with free shipping. You can also buy a 45-capsule bottle from for $44.99 plus $5.00 for shipping.

Money-Back Guarantee

Metabolic Nutrition provides a 30-day money-back guarantee on all of its products.[14]Simply return the item(s) to the company within 30 days of purchase.

If you are returning multiple items, you’re only allowed to open one of the bottles.

Final Thoughts

While many users have seen significant weight loss with Synedrex, most experienced negative side effects as well. Given the recent FDA banning of DMAA and questionable safety of the product, I suggest you pass on Synedrex. There are plenty of safe, effective diet pills backed by more up-front companies.

[1] Better Business Bureau. “Metabolic Nutrition.” Accessed 4.19.2013. Available from:[2] University of Maryland Medical Center. “Vitamin B3 (Niacin).” Accessed 4.19.2013. Available from:[3] Korthuis RJ. Skeletal Muscle Circulation. San Rafael (CA): Morgan & Claypool Life Sciences; 2011. Chapter 4, Exercise Hyperemia and Regulation of Tissue Oxygenation During Muscular Activity. Available from:[4] Office of Dietary Supplements. “Vitamin B12.” Accessed 4.19.2013.Available from:[5] See Freund, Herbert, et al. “Chromium deficiency during total parenteral nutrition.” JAMA: the journal of the American Medical Association 241.5 (1979): 496-498. Available from:[6] Osswald, Hartmut, and Jürgen Schnermann. “Methylxanthines and the kidney.” Methylxanthines. Springer Berlin Heidelberg, 2011. 391-412. Available from:[7] Dini, F. L., et al. “Methylxanthine drug therapy in chronic heart failure associated with hypoxaemia: double-blind placebo-controlled clinical trial of doxofylline versus theophylline and bamifylline.” International Journal of Clinical Pharmacology research, 13.6 (1993): 305. Available from:[8] See Stohs, Sidney J., et al. “Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes.” International Journal of Medical Sciences, 8.4 (2011): 295. Available from:[9] See Westerterp‐Plantenga, Margriet S., et al. “Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation.” Obesity Research, 13.7 (2012): 1195-1204. Available from:[10] Sobolevsky, Tim, Grigory Rodchenkov. “Sulbutiamine in sports.” Drug Testing and Analysis, 2.11‐12 (2010): 643-646. Available from:;=false&deniedAccessCustomisedMessage;=”[11] Micheau, Jacques, et al. “Chronic administration of sulbutiamine improves long term memory formation in mice: possible cholinergic mediation.” Pharmacology Biochemistry and Behavior, 23.2 (1985): 195-198. Available from:[12] “Dimethylamylamine.” Accessed 4.19.2013. Available from:;=DIMETHYLAMYLAMINE”[13] U.S. Food and Drug Administration. “Q & A on DMAA in Dietary Supplements.” Accessed 4.22.2013. Available from:[14] “Returns.” Accessed 4.19.2013. Available from:

About the Author: Holly Sanchez

Holly Sanchez is an award-winning professional health, beauty and fitness writer and completed Master of Science in Exercise Science & Nutrition. Holly specializes in health, fitness, man/women issues, and nutraceuticals. Holly travels the world sharing the secrets, pros, cons, reviews of the health supplement and helping the buyer to get the best supplement they are looking for. Writing published on, New York Times etc

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