Warning icon /> Please upgrade your browser.
Suggest it for testing.
Submit your suggestion



Labdoor tested 27 of the best-selling energy products in the United States for active ingredients, including caffeine, taurine, B-vitamins, vitamin C, vitamin E, quercetin, and 5-HTP (5-hydroxytryptophan).

On average, products in this testing batch recorded 105 mg of caffeine per serving, ranging from 1.3 mg to 245.1 mg per serving. Products generally performed well in label accuracy; only 3 products measured caffeine levels more than 10 % above or below their label claims. The FDA has cited 400 mg of caffeine per day as "an amount not generally associated with dangerous effects"1. Other active ingredients like taurine2, quercetin3, ginseng4, and ginkgo biloba5 have been associated with energy benefits, but related research has either found insignificant benefit or studies were inconclusive overall. Analysis also found sodium benzoate, a preservative linked to carcinogenicity6, in 12 products and acesulfame potassium7, a controversial artificial sweetener, in 8 products.

Analytical Chemistry Methods: HPLC (caffeine, taurine, B-vitamins, vitamin C, vitamin E acetate, quercetin, 5-hydroxytryptophan)



All but 3 products recorded caffeine levels within 10% of their respective label claims.

22 of 27 products recorded caffeine levels within 10% of their respective label claims. Measured caffeine levels ranged from -35% to +29% compared to label claims. In contrast to relatively accurate caffeine claims, products deviated an average of 45%, 210%, 93%, and 800% compared to label claims for vitamins B3, B6, B12, and B9 (folate), respectively.



Additional chemical analyses are needed to assess product purity.

Labdoor does not currently perform product purity testing or supply chain analysis on energy products.



Soft drinks and coffee-based products contained excessive sugar, with up to 41 grams (about 10 teaspoons) per serving.

Analysis found that energy shots and products marketed as low-calorie options indeed had fewer calories, ranging from 0 to 10 calories per serving. Other product subcategories recorded up to 150 calories per serving, with a significant portion coming from added sugars. These products recorded an average of 28 g (about 3 teaspoons) of sugar per serving.



18 of 27 products recorded the controversial additives, sucralose, acesulfame potassium, andor sodium benzoate.

CAFFEINE: The FDA has cited that caffeine is safe even up to 400 mg of caffeine per day1. 7 of 27 products in this batch analysis exceeded 150 mg of caffeine in one serving. BSN Endorush measured the highest caffeine levels in this batch with 224 mg per serving (448 mg per container).

OTHER ACTIVE INGREDIENTS: In 20 products with vitamin B3, products measured up to 60 mg of vitamin B3 per serving. The established Tolerable Upper Intake Level (UL) for the nicotinic acid form of vitamin B3 is 35 mg per day for adults, based on the temporary appearance of flushing, tingling, or nausea 30 minutes to 6 weeks after an initial dose. The UL for folate is 1000 mcg per day in adults based on the risk of masking symptoms of vitamin B12 deficiency like neurological damage8. One product, 5-Hour Energy Extra Strength exceeded this limit. All other measured active ingredients were found to be within safe limits.

ADDITIVES: The controversial artificial sweeteners, sucralose9 and acesulfame potassium7, were recorded in 15 and 8 products, respectively. 12 products recorded sodium benzoate, a preservative linked to carcinogenicity6.

Several ingredients in energy products have been found to interact dangerously with certain medications. Please consult your physician before consuming these products, especially if you have a medical condition, are pregnant, or are taking any other drugs or dietary supplements.



All tested products contained caffeine, measuring an average of 105 mg of caffeine per serving.

CAFFEINE: Products measured an average of 105 mg of caffeine per serving. 10 of the products had about 80 mg per serving, comparable to the caffeine in a cup of drip-brewed coffee. Clinical study supports caffeine's energy-boosting effects. Research shows that arousal effects in nondependent caffeine users were noticeable with acute doses as low as 50 mg10. In exercise studies, 6 mg per kg bodyweight of caffeine was able to improve performance in anaerobic exercises11,12.

B-VITAMINS: All but 3 products contained vitamins B3, B6, B9 (folate), andor B12, often in amounts much higher than what is needed for healthy functioning. Fatigue is a common symptom of not consuming enough of these vitamins, but if intake is already adequate, supplementation has not been shown to help improve energy status13.

TAURINE: 15 products measured taurine, with an average of 404 mg of taurine per serving. Taurine is an amino acid involved in heart contraction and antioxidant activity14. Standard dosing has not been established, and research is inconclusive about the benefits of taurine for energy or exercise performance.



  • 10 Childs E & de Wit H. (2006). Subjective, behavioral, and physiological effects of acute caffeine in light, nondependent caffeine users. Psychopharmacology (Berl).
  • 11 Pontifex KJ, et al. (2010). Effects of caffeine on repeated sprint ability, reactive agility time, sleep and next day performance. The Journal of Sports Medicine and Physical Fitness.
  • 12 Carr AJ, et al. (2011). Induced alkalosis and caffeine supplementation: effects on 2,000m rowing performance. International Journal of Sport Nutrition and Exercise Metabolism.
  • 13 University of Maryland Medical Center. (2013). Complementary and Alternative Medicine Guide.
  • 14 Williams M. (2005). Dietary Supplements and Sports Performance: Amino Acids. Journal of the International Society of Sports Nutrition.
  • 1 FDA. (2013) FDA to Investigate Added Caffeine.
  • 2 Mayo Clinic. (2015). Taurine is listed as an ingredient in many energy drinks. What is taurine? Is it safe?
  • 3 Bigelman KA, et al. (2011). Effects of 6 weeks of quercetin supplementation on energy, fatigue, and sleep in ROTC cadets. Military Medicine.
  • 4 Yuan C, et al. (2002). Ginsenoside variability in American ginseng samples. The American Journal of Clinical Nutrition.
  • 5 University of Maryland Medical Center. (2015). Ginkgo biloba.
  • 6 FDA. (2015). Data on Benzene in Soft Drinks and Other Beverages.
  • 7 NHS. (2016). Acesulfame K: the evidence.
  • 8 Institute of Medicine. (1998). Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline.
  • 9 Schiffman SS & Rother KI. (2013). Sucralose, A Synthetic Organochlorine Sweetener: Overview of Biological Issues. Journal of Toxicology and Environmental Health. Part B, Critical Reviews.