What is creatine?
Creatine is the most popular supplement used for performance enhancement on the market. If you take this or are thinking about taking this, you came to the right place! As a Board Certified Internal Medicine physician, my goal is always to relay to you not only the benefits, but the risks of supplements, like creatine. My approach is that we should manage supplements as we would medications in terms of blood test monitoring and follow-up with your physician. As always, your safety is paramount to me.
What is creatine? Well, it’s a combination of three amino acids, which are the building blocks of protein. The three amino acids are called arginine, glycine and methionine.
95% of creatine is naturally found in one of your three muscle types called the skeletal muscle. Skeletal muscle is the only type that you can voluntarily control, for example while doing bicep curls during a workout. Of the creatine in your skeletal muscle, 65% of it is stored in a form called “phosphocreatine”.(1) I’ll try to help you visualize the following reaction with an analogy that is illustrated in the diagram below. Think of phosphocreatine as a match that has been lit. Now imagine a firework with a wick on the end of it, with the wick being an “ADP” molecule. The resultant ignited firework exploding into the sky, would be the “ATP” molecule. In this analogy, the phosphocreatine (the lit match) passes a phosphorus group (the fire) to the ADP (the wick) converting it to ATP (the exploding firework) in order to power the contraction or movement of your muscle. The ATP in this case powers the muscle to perform short duration/high intensity exercise (analogous to the firework blasting off and exploding into the sky). This is done with the help of an enzyme called creatine kinase, which would be the person’s hand lighting the match in this analogy.
I know that was pretty technical, but I really want you to understand how this supplement works. Okay, one last thing about the biochemistry of this… I promise. When you take creatine, you INCREASE the RATE of phosphocreatine re-synthesis. In other words, you are lighting the match over and over again more frequently to ignite more and more fireworks. In the end, creatine can enhance your performance and recovery.
In general, the point of taking creatine is to make your muscle movements faster and stronger. It also pulls water into the muscle cells giving the muscles themselves a bigger and more full appearance.
Another potential benefit that is less talked about is the effect on cognitive functioning. There was a study done in the British Journal of Nutrition by Benton et al. in 2011, in which 128 young adult females were studied. They were separated into two groups randomly so there was a mix of those that ate meat and those that were vegetarians in both groups. Remember, those that were eating meat were essentially eating creatine, because meat is composed of muscle. At random, some from each group were given either 20 grams of creatine or a placebo for 5 days. The study found that those who were vegetarian showed an improvement in memory(2), while the meat-eaters showed no change (implying the meat-eaters were already “topped off” from their diet, while the vegetarians were in a deficiency that was corrected by creatine supplementation).
Additionally, higher creatinine levels in the brain, as a result of creatine supplementation, can result in improved cognitive processing when it is impaired by aging or sleep deprivation.(3)
Now to the good stuff… How do you start creatine? You can start it through a “loading” process in two ways. The first is an “acute load” that requires a dose of 0.3mg/kg/day. That daily dose is then divided into four doses a day and taken for a total of 5 days. For example, if you are a 70kg person, you would require a dose of 21g/day (which is 70kg x 0.3mg/kg/day). You then divide that daily dose of 21g into four doses of 5.25g. So, you would end up taking 5.25g four times per day for 5 days. Alternatively, you can do a “chronic load” of 3g/day for 28 days. Once you complete the acute or chronic loading process, then you should continue a “maintenance dose” of 2-3g/day thereafter.
Easy right? Not so fast. Keep in mind that 30% of you may be “non-responders” and it may not work for you. If it does work for you and you continue taking it, there are some potential side effects. Unfortunately, it can sometimes cause water retention, reduced joint mobility and muscle cramping. I know what you’re thinking – what about kidney damage? Well, the overall evidence is not very supportive of creatine causing kidney damage. This assertion is not based on strong research. However, if you do have signs of kidney damage on your blood tests, this will require some investigation by your doctor.
The way we measure the health of your kidneys is by assessing your creatinine level (Notice the word here is CREATININE and NOT CREATINE). The normal range of creatinine varies according to the laboratory where it is analyzed, but generally ranges from 0.84 to 1.21 mg/dL. Creatinine is a breakdown product of creatine and is normally filtered from the blood by the kidneys into the urine. But, if the kidneys are “damaged” they may not be filtering properly which can result in an elevated creatinine value. Thus, as physicians, we tend to interpret an elevated creatinine value as an indirect indicator of kidney damage. However, keep in mind that the creatinine can be elevated for reasons other than kidney damage. For example, your creatinine can be temporarily elevated by taking certain medications like cimetidine, aspirin, active vitamin D metabolites and trimethoprim which is one of the ingredients in a common antibiotic called Bactrim®.(4) Also, your creatinine level can double in value 2-4 hours after eating cooked meat.(5) My point here is that if your creatinine is elevated, it does not necessarily mean that you have a kidney issue. It is for this reason that a nuanced approach with your physician is critical to interpreting your blood test result.
Now that I’ve cautioned you, I would like mention that there are different forms of creatine on the market. But, the oldest, most studied and safest form is “creatine monohydrate”.
You should also be aware that according to the American College of Sports Medicine, creatine should NOT be used by adolescents under the age of 18. The safety of creatine supplementation in this age group is not well-established.
Well, now that you know how creatine works, how to use it and what to look out for, please remember to consult with your physician before and during use of creatine and any other supplement for that matter. As a National Academy of Sports Medicine certified personal trainer, I want you to achieve the best of your fitness goals. But, as a physician, I want you to be safe and take care of your body. Good luck and stay safe!
Khris Ramdeen, MD
Board Certified in Internal Medicine
National Academy of Sports Medicine (NASM) certified personal trainer
1. UpToDate, Robinson et al, Permitted non-hormonal performance-enhancing substances
2.The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores, British Journal of Nutrition, Volume 5, Issue 7, April 2011, pp. 1100-1105, David Benton and Rachel Donohoe
3.Rawson, E.S. & Venezia, A.C. Amino Acids (2011) 40: 1349. https://doi.org/10.1007/s00726-011-0855-9
4.Andreev et al. 1999
5.Willis, J et al 2008