Navigating the Difficult World of Supplements

Navigating the Difficult World of Supplements

By Matthew Kaufman, MD

When you think about nutritional supplements for athletic performance, you may imagine an advertised “get fit quick!” and a promise to change your whole life. I remember when friends, teammates or a coach would tell me about a supplement, I would often tune it out for a couple of different reasons. First, we must be aware that if it sounds too good to be true it probably is. Second, the supplement industry does not follow the same FDA standards that other drugs or medications have. This means that some of the supplements people buy may not contain adequate levels of different ingredients or may even contain things that might be harmful to your health like mercury or arsenic.


So instead, I decided to investigate these supplements myself and found some interesting research. From my findings, I gathered three big takeaways: (1) Some supplements are safe and rooted in research, while others have mixed evidence for their efficacy, (2) what are considered the most effective supplements surprised me- and may surprise you, and (3) in shopping for supplements, it is difficult to determine how to find the best value.


Most common supplements are safe when used and sourced appropriately. For instance, Creatine, a protein our body naturally uses for quick sources of energy and can be used to improve power in high intensity exercise performance, does not lead to kidney dysfunction when taken as recommended (ie. 5g four times daily, or 0.3g/kg of body weight for 5-7 days as a loading dose and then 3-10g/day for maintenance dose) and does not need to be cycled on and off as previously thought. In fact, vegans and vegetarians may benefit even more from daily creatine supplementation because they do not get as much from their diet. With more and more athletes exploring vegetarian, vegan, and plant-based diets to promote longevity, Creatine supplementation may become more important down the line. With common supplements such as Creatine, Caffeine, B-Alanine, BCAA’s, Citrulline, Arginine and Beet Root Juice, minimal safety concerns have been reported from the thousands of research studies conducted. This means the risk of taking these supplements is overall low, so if you feel inclined to try one for yourself, you can feel safe in doing so after discussing with your healthcare provider. Overall, it is important to understand that the common supplements that people take are well regarded for their safety, and after proper consultation with a medical practitioner, will likely not lead to long term consequences.


There was also a surprising amount of evidence supporting the efficacy of different supplements for sports performance. Caffeine, for example, has robust evidence for improving performance for athletes. Caffeine has been shown to increase power and velocity in strength training and performance in boxers, shot put, rowers and cyclists. On the other hand, while Branched Chain Amino Acids, or BCAAs, are one of the most popular supplements, the actual evidence did not robustly support their use in sports performance. BCAAs are a specific group of amino acids consisting of isoleucine, leucine and valine that are thought to be linked to recovery and prevention of muscle breakdown. International societies have even weighed in with the Australian Institute of Sport giving BCAAs a grade “C”, meaning that the current evidence is not supportive of benefit amongst athletes OR no research has been performed to guide an informed opinion. Dietary Nitrates, like Beet Root Juice, and Caffeine have an “A”, meaning that there is strong evidence for certain situations in sport with evidence-based protocols. For instance, there is strong evidence, that Beet Root Juice supplementation can lead to prolonged high-end effort as well as improved average and max power especially in the endurance athlete. It is important to realize that every supplement may not help sports performance in all domains. Understanding how each supplement can impact your strength, endurance, recovery, and other aspects of exercise and sport is crucial to knowing the appropriate situations where each supplement is warranted.


Finally, my research showed how difficult it can be to purchase the right supplement. When visiting a popular internet marketplace, I had no idea where to start. There were numerous blends of different supplements, with different concentrations and all at different price points. With this immense variation, it is incredibly difficult for any buyer to determine the right product for them.


Here are 5 easy steps I recommend for finding quality supplements that will help you meet your athletic goals:

  • Meet with your healthcare provider to decide if and what supplement is appropriate for you and your goals. Make sure to discuss things like the proper dosage and time course!
  • Check for safety information for your supplement on MedWatch (the FDA reporting site for adverse events and reactions).
  • Check for quality and accuracy of reported ingredients in your supplement at ConsumerLab, US Pharmopecia, and NSF International.
  • Check the price of your supplement across multiple stores and vitamin shops to ensure you find the most cost-effective option.
  • After deciding the proper supplement with your physician, report your experience with them!



From this investigation of sports supplements, it’s clear how important it is that people understand exactly what they are taking, but this is no easy task. Because supplements are not regulated in the same ways as medications, we as consumers must complete the necessary research ourselves. We need to ask ourselves, “What really is in these supplements?” and “What is the impact of the supplement’s ingredients?” The best thing to do would be to talk about your goals with a physician or medical professional who understand these supplements and can recommend a trusted brand or source. Don’t miss the full systematic review, Supplements for Athletic Performance, that will be published in the coming months.