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5-Hour Energy®: Product Review


5-Hour Energy®: Product Review

Many people who are looking to get a quick boost of energy are drinking 5-Hour Energy®. While some people do not feel much of an effect from this very popular drink, others swear by its ability to prevent the dreaded “crash” that occurs during a long or demanding day.

Living Essentials, the producer of the drink, describes 5-Hour Energy as a 2-ounce liquid energy shot that can help you feel sharp and alert for hours. It contains a blend of B vitamins, amino acids, and nutrients, with zero sugar, zero herbal stimulants, and only 4 calories.

Which vitamins, amino acids, and nutrients are in the product? How do they promote a sustained boost of energy? This product review will answer these questions and:

  • Evaluate the primary ingredients of 5-Hour Energy and how they affect the body
  • Identify the types of individuals who should avoid taking 5-Hour Energy and those who should speak with a doctor before taking it
  • Provide a summary of the product, its ingredients, and its proposed effectiveness

B vitamins
The four B vitamins found in 5-Hour Energy are niacin (150% of daily requirements), B6/pyridoxine (2000% of daily requirements), folic acid (100% of daily requirements), and vitamin B12 (8333% of daily requirements). These B vitamins are involved in many processes throughout the body, including carbohydrate, protein, and fat metabolism, red blood cell creation, and cognitive function. While supplementing with these vitamins can benefit those with deficiencies, people consuming a well-balanced, nonvegan diet should have little trouble getting adequate amounts of these vitamins from food. Vegans should ensure they are getting a particular source of vitamin B12 in their diet.

Despite the large doses of B vitamins found in this product, most excess B vitamins are easily processed by the body and eliminated in the urine. However, some people are sensitive to niacin and can develop a side effect called “niacin flush,” which causes skin redness and a hot, prickly feeling, which subsides after a few minutes.

Taurine, an amino acid derivative of cysteine, is found throughout the body, including the lower intestines, bile, muscle, and brain. While evidence exists to show that taurine supports neurological development, no studies demonstrate its effectiveness for increasing energy or focus. The only clinical uses established for taurine are in the treatment of congestive heart failure and possibly acute viral hepatitis. While typical supplement doses of 2-4 grams/day are generally considered safe, few studies have looked at the long-term effect of taurine combined with other neurological stimulants, such as caffeine. Taurine is found naturally in fish and meat, and the body can create it from other amino acids and vitamin B6. Deficiency is rare.

Glucuronolactone, a metabolite of glucose, is used throughout the body as a connective tissue component, vitamin C precursor, and regulator of glycogen breakdown. Very little research exists for glucuronolactone as a stand-alone supplement, because it usually is combined with caffeine and taurine in energy drinks. Some studies show the potential for increased energy via heightened insulin levels, but this is not proven in any human population.

Malic acid
Malic acid is found naturally in many fruits and vegetables, particularly tart fruits, such as apples and grapes. Malic acid is produced constantly and is broken down in the body as a part of the cell’s natural energy creation process (the Krebs cycle). While studies support a potential benefit to increase energy levels for people with fibromyalgia, little evidence shows that supplemental malic acid will increase energy and metabolic levels in healthy populations.

N-acetyl L-tyrosine
Tyrosine is a nonessential amino acid formed from phenylalanine (see L-phenylalanine), which is a building block for brain neurotransmitters, including dopamine and epinephrine. These brain chemicals affect nerve cell response and mood. According to the University of Maryland Medical Center, “Some animal and human studies suggest that tyrosine supplements may help improve memory and performance under psychological stress, but more research is needed.”

In addition, tyrosine regulates the adrenal, thyroid, and pituitary glands, and is involved in most protein formation. Tyrosine deficiency is rare, because your body can make the amino acid on its own. You can find tyrosine in many foods, including poultry, fish, soy, dairy, and legumes.

L-phenylalanine is an essential amino acid found in many foods, including dairy products, poultry, fish, legumes, nuts, and green-leafy vegetables. Phenylalanine is converted to tyrosine, which regulates proteins, hormones, and brain chemicals, including dopamine and epinephrine. These brain chemicals are associated with mood improvements in people with depression, though rigorous studies have yet to prove these effects conclusively. You can meet your daily requirements through a balanced diet.

Original 5-Hour Energy has caffeine equivalent to the amount found in one cup of coffee, about 100-200 milligrams. The world’s most frequently consumed psychoactive drug, caffeine occurs naturally in some foods and beverages, such as coffee, tea, and chocolate. However, caffeine sometimes is isolated for use in supplements and pharmaceuticals, such as headache medications and 5-Hour Energy.

The three effects most commonly associated with caffeine use are increased mental alertness, increased urination, and headache reduction. According to PubChem, caffeine promotes these effects in you by relaxing smooth muscle, stimulating cardiac muscle, and promoting diuresis.

Citicoline, also known as CDP-choline, naturally forms in the body during the formation of structural phospholipids for cell membranes. According to a review by Secades and Lorenzo, citicoline is shown to increase brain metabolism and increase norepinephrine and dopamine levels, effects similar to tyrosine and phenylalanine. Studies on citicoline primarily have focused on recovery from head trauma, brain damage, and cognitive impairment (eg, Alzheimer’s disease and Parkinson’s disease), not on its general effects on alertness and focus.

The generic form of Splenda®, sucralose is an artificial sweetener found in many different sodas and drinks particularly created for diabetics or those looking to reduce sugar from their diet. This is why 5-Hour Energy has “zero sugar.”

Summary of 5-Hour Energy
The combination of caffeine, taurine, and B vitamins is a popular combination for many popular energy drinks. The only supplement to have a proven effect on neural stimulation is caffeine. The amount of caffeine included in 5-Hour Energy is similar to the amount found in a cup of coffee. You can consume all of the other ingredients found in 5-Hour Energy in a balanced diet.

Note: Certain populations should avoid taking 5-Hour Energy, including individuals who are pregnant, nursing, under 12 years of age, or phenylketonurics. Living Essentials also advises that consumers contact their doctor before using 5-Hour Energy if they are taking medication and/or have a medical condition.

In general, supplements have very few regulations and often are brought to market without proving their effectiveness. In fact, many supplements are sold solely based on theoretical metabolic pathways in humans or animals. In other words, many supplements could work, but few are studied to actually prove that they do work. Supplements only come under scrutiny if they cause harm, such as ephedrine.


References and recommended readings

Living Essentials, Inc. 5-Hour Energy: ingredients & safety.
Available at:
Accessed January 10, 2011.

Living Essentials, Inc. How to use 5-Hour Energy Shots: product directions.
Available at:
Accessed January 10, 2011.

NYU Langone Medical Center. Taurine.
Available at:
Accessed December 3, 2010.

Rogers M. 5-Hour Energy: the healthy energy drink?
Available at:
Accessed December 3, 2010.

Secades JJ, Lorenzo JL. Citicoline: pharmacological and clinical review, 2006 update. Methods Find Exp Pharmacol. 2006;28(suppl B):1-56. Exploring the benefits of malic acid.
Available at:
Accessed December 3, 2010.

University of Maryland Medical Center. Phenylalanine.
Available at:
Accessed on 12/3/2010.

University of Maryland Medical Center. Tyrosine.
Available at:
Accessed December 3, 2010.

Wells S. Glucuronolactone and the athlete.
Available at:
Accessed December 3, 2010.

Wikidot. The effects of glucuronolactone to the body.
Available at:
Accessed December 3, 2010.

Zeratsky K. Taurine in energy drinks: what is it?
Available at: http://www.mayocli
Accessed December 3, 2010.


Contributed by Jason Machowsky, MS, RD, ACSM-cPT

Review Date 2/11


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