This is an important study as it finds stimulants in pre workout type supplements – currently all the rage in the marketplace – can range significantly over time for the same product, up to 266%! When you combine various stimulants – many of which are listed in the abstract below – it can be potentially dangerous. Manufacturers of such products need to do a far better job of their quality control. Before anyone comments the FDA needs to regulate supplements, I’d recommend reading my article HERE on the total failure of FDA “regulated” drugs and the massive (yet never mentioned in the media…) quality control failures of pharma.
Although the authors of this study admit their sample size was insufficient to support statistical analysis, I commend them for examining “Three samples of nine popular sports supplements were purchased over the nine-month period” vs just pulling a single sample off the shelves of some store and making the conclusions they did. I think their sample size and methodology sound enough that people should take note that it’s very likely the stimulant levels in the pre workout supplements they use may be all over the place dose wise. Many ingredients found in nutritional supplements are non toxic at levels well above label claims, especially acutely, but stimulants, especially mixtures of various stimulants, can be problematic. Per usual, buyer beware!

Some popular pre workout formulas

Some popular pre workout formulas

Variability of Stimulant Levels in Nine Sports Supplements Over a Nine-Month Period.

Int J Sport Nutr Exerc Metab. 2016 Feb 3.
Many studies have found that some dietary supplement product labels do not accurately reflect the actual ingredients. However, studies have not been performed to determine if ingredients in the same dietary supplement product vary over time. The objective of this study was to assess the consistency of stimulant ingredients in popular sports supplements sold in the United States over a nine-month period.
Three samples of nine popular sports supplements were purchased over the nine-month period. The 27 samples were analyzed for caffeine and several other stimulants (including adulterants). The identity and quantity of stimulants were compared to stimulants listed on the label and stimulants found at earlier time points to determine the variability in individual products over the nine-month period.
The primary outcome measure was the variability of stimulant amounts in the products examined. Many supplements did not contain the same number and quantity of stimulants at all time points over the nine-month period. Caffeine content varied widely in five of the six caffeinated supplements compared to the initial measurement (-7% to +266%).
In addition, the stimulants – synephrine, octopamine, cathine, ephedrine, pseudoephedrine, strychnine, and methylephedrine – occurred in variable amounts in eight of the nine products. The significance of these findings is uncertain: the sample size was insufficient to support statistical analysis. In our sample of nine popular sports supplements, the presence and quantity of stimulants varied over a nine-month period.
However, future studies are warranted to determine if the variability found is significant and generalizable to other supplements.

  1. Glen 7 years ago

    Great article.So many pre-workout products out there.All essentially tout they are the best.

    • Author
      Will Brink 7 years ago

      That goes for pretty much any product though. Problem with these products, is there’s an arms race as to who can makes the strongest products in the category, and that can be problematic and potentially dangerous.

      • NJJoe 7 years ago

        Not just pre workouts, but energy drinks in general. The amount of caffeine can often be much more than than what its labeled to be. As I’ve said, I’ve seen far too many young kids (under 18) rushed to the emergency room for arrhythmia, palpitations, hypertension, and other “over stimulated” symptoms, which in worse case could be deadly. If you’re an adult, and wanna chug down 8 cups of coffee, or 5 energy drinks, go ahead. But these things should at least carry a warning, and coaches and schools should help educate parents and kids alike about the possible side effects.

  2. Ross 7 years ago

    Ill never forget your vid where you say if you always need a preworkout you should take up golf because your a big fat pussy lol

    • Author
      Will Brink 7 years ago

      That was from my vid on my the homemade recipe I recommended linked below.

  3. John 7 years ago

    Whatever happened to having a cup of coffee or black tea? Now they want you to think you need a supplement to workout.

  4. stanley sekelsky 7 years ago

    What about Tectanic Red? Not sure there’s anything wrong with it?

    • Barrett Butler 7 years ago

      I would like to see some 3rd party on that. Alex Rogers over at Protein Factory is a well meaning guy. For sure 3rd party tested for content and FDA 111 certified

      • Author
        Will Brink 7 years ago

        I agree. Best thing a company, or group of companies, could do would be to reproduce that
        study using a third party location. It would be neither terribly expensive nor difficult to do.
        However, my advice that companies step up and fund good research that will help both
        sell more product and or defend the industry that pays their bills tends to fall on deaf ears
        in favor of over hyped marketing and BS.

  5. NJJoe 7 years ago

    Pre workouts, who needs them! Man up and drop your dependence. If you can’t get it up for your workout, stay home. Back in the day, so to speak, if you were felling sluggish, a cup, that’s 8 oz., of regular coffee would suffice. These energy drinks, over caffeinated chemical stimulant powders are dangerous, especially in the young. Far too many kids are being rushed to emergency rooms because of this crap. There’s been a lot of concern that that the FDA is going to have to step in because of this exact issue, that is, the industry, at least in so far as these products are concerned, is unable to regulate itself. In this sole case, I welcome it.

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