Creatine: Powder or Serum?

February 2005


1- Featured Article: Powder or Serum?

I’ve been online for more than five years now. And, over the last few years I’ve noticed a gradual change in the nature of the questions that are being asked by my online visitors. In the past, such inquiries were more concerned with understanding the general mechanisms of how creatine works. Recently, the queries are more about the efficacies of specific creatine formulations currently on the market. Obviously, my readers are becoming more sophisticated; I can only hope that I may have had a small part to do with their evolution. Nevertheless, by far, the question I am most frequently asked of this genre is: “Which is better, powder or serum?”. In this issue of the Creatine Newsletter I tackle this question with the assistance of a publication that appeared in the scientific literature just last year.

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This Month’s Featured Article:

Powder or Serum?

by Alfredo Franco, PhD

Sometimes it is wisest not to try to improve on an already good thing? While the benefits of creatine monohydrate powder have been amply demonstrated in countless scientific studies over the last decade, many of the more recently developed creatine formulations remain virtually unstudied. In particular, one hotly pursued product development is an effective liquid formulation of creatine. This branch of innovation, however, is plagued by two nearly inevitable physical-chemical attributes of creatine monohydrate.

Firstly, creatine monohydrate is rather insoluble. Normally, half a liter (~17 ounces) of solution is required to fully dissolve only 6-7 grams of creatine monohydrate. Therefore, given that typical doses of creatine range between 2 and 20 grams a day, the sheer volume of liquid product that would be necessary to supply only a week’s worth of creatine, makes this option highly impractical.

Secondly, creatine monohydrate readily degrades in aqueous solutions. Creatine in water spontaneously transforms into another form of the molecule known as creatinine. Creatinine is the exact same degradation product of creatine produced within the body and, while relatively harmless, renders no physical benefit. In fact, the steady conversion of creatine into creatinine in our muscles is the reason that creatine supplementation is a daily process. Therefore, the formation of creatinine in a liquid formulation will essentially dilute the amount of active creatine available to your muscles. Creatinine, on the other hand, is nearly ten-times more soluble than creatine in aqueous solutions. It would thus make sense that a highly concentrated ‘creatine’ solution (not suspension) would, by necessity, consist almost exclusively of creatinine. Obviously, the development of a practical and stable liquid formulation of creatine is no simple feat – to say the least.

Study Title: Creatine serum is not as effective as creatine powder for improving cycle sprint performance in competitive male team-sport athletes.

As the title implies, this study compared the efficacy of a commercially available liquid formulation of creatine with that of ordinary creatine monohydrate powder.

Experimental Design

This study consisted of a randomized crossover, double blind design. This is a mouthful, but it simply means that the subjects were randomly assigned to one of two groups. Half the subjects commenced the study by supplementing with the powder, while the other half began with the serum. Crossover, on the other hand, means that all subjects eventually supplemented with both serum and powder after a delay. Following a washout period of seven weeks to allow a complete return to baseline, subjects switched to the opposite supplementation category. Hence, each subject served as his own control scenario. In other words, in the case that a person was a super-, or non-, responder, he (the study used males) would have the opportunity to do so for both supplement conditions. Double blind signifies that neither subject, nor experimenter, knew who was taking which supplement, just in case there was any personal bias (by subject or experimenter) that could influence the results. It would be fair to say that the authors of this study were careful.

Eleven male athletes were selected to participate in the study. Subjects were of college age (23 + 2 years) and of average body composition; 1.77 + 0.06 meters height and 75 + 10 kilograms of body weight. Although it would have been nicer to have more participants in the study to increase the statistical significance of the measurements, a small sample size if fully understandable. Human studies are expensive to conduct, and increase in expense with the number of subjects.

The exercise task being examined was a series of 10 brief (6 seconds) ergometer cycle sprints. Each sprint was separated by a rest period of 24 seconds. This sort of exercise falls well within the realm of the physical tasks that are most strongly influenced by creatine supplementation. Other precautions were also applied. First, each volunteer was familiarized with the cycling task before the actual experimental run, so that all started off from the same cognitive base. Secondly, the resistance of the bike as well as the seat height and position were adjusted to match each subject’s unique physical characteristics. Thirdly, all subjects selected to participate in the study were competitive male athletes to control for possible differences in fitness level influencing the results of the study. Finally, all participants of the study were asked to refrain from the use of caffeine and alcohol at least 12 hours before commencing the test. The reasons for these last two stipulations are discussed in my creatine guide.

Each supplement was taken “according to the manufacturer’s recommendations“. That is, the powder was ingested utilizing a traditional loading protocol consisting of 20 grams of creatine monohydrate a day for six days. Each daily loading amount of powder was divided into 5 gram increments that were dissolved in 250 milliliters (~ 8.5 ounces) of orange juice immediately before being ingested; one 5 gram dose was taken every 3-4 hours. The serum was taken only once per day, immediately prior to exercise, in a much smaller volume, 5 milliliters. Each 5 milliliter dose of the serum is reported by the manufacturer (MMUSA) to contain 2.5 grams of creatine.

The brand of liquid formulation used in the study was Creatine SerumTM by Muscle Marketing USA (MMUSA). The creatine monohydrate powder was obtained from a manufacturer in New Zealand. There was nothing extraordinary about the creatine monohydrate powder used.

Study Results

As expected, peak power declined with each successive sprint (see figure below). This tendency should make intuitive sense from everyday experience. When performing all out bouts of exhaustive exercise, your power decreases with time. Thinking of the bench press may help you visualize this effect. Nevertheless, despite this predictable trend, a clear difference was observed in how the two products influenced power output. The blue symbols represent the data points (one point for each sprint of a series of ten) obtained BEFORE the ingestion of either the powder or serum as indicated. The red symbols, on the other hand, show the data obtained AFTER the subjects had supplemented with the indicated creatine product. To accentuate any apparent differences a line was drawn joining data points of a given experimental condition. An effect by a product would be manifested as a separation of the two lines.

This figure represents data that was adapted from the study of Gill et al., 2004. The error bars were removed for clarity. Power is defined as the amount of work performed per unit time and is given in watts. Both plots are set to the same scale.

An effect of the powder was observed as soon as the first sprint trial and continued throughout the series until the tenth run. On the other hand, the Creatine SerumTM was rather ineffective at improving power output within the experimental constraints of the study. Strangely, the serum-supplemented subjects may have actually experienced a slight drop in power (less than 1%), although this effect was clearly within the inherent noise level of the measurements.

It is worth noting, however, that the subjects supplementing with the Creatine SerumTM appeared to have started at a higher power level as is indicated by the dotted line on the power axis, which is set to the same level in both plots. This is evidenced by the fact that the first few blue symbols (serum-unsupplemented) fall above the dotted line. In a sense, this might be taken to mean that those taking the serum had less room for improvement. This detail needs to be examined more closely.

This line of serum products also contains additional ingredients that could have influenced the results. These include vitamin B12, Royal Jelly, ginseng, glycerine, honey, glucosamine and flavorings. However, without knowing the exact product used (there are several), it’s difficult to tell which were present. Nevertheless, from the results, these ingredients didn’t seem to assist in improving brief sprint performance. Perhaps they have other benefits, but assisting in this particular type of activity (in the short-term) doesn’t appear to be one of them.


Ironically, the underlying problem with the comparison conducted in this study was that both creatine products were taken according to the ‘manufacturer’s recommendations’. Consequently, both sets of subjects ended up consuming vastly different amounts of creatine. Those subjects ‘loading’ with the powder consumed 20 grams of creatine per day. By stark contrast, the amount of creatine monohydrate consumed with a daily dose of serum was only 2.5 grams, eight times less. This, of course, is assuming that the manufacturer’s (MMUSA) estimation of the amount of creatine contained within the serum was correct, which, as you will learn in the next issue of the Creatine Newsletter, may have been erroneous.

Closing Comments

This study gets us one step closer to the answer of whether creatine monohydrate powder or Creatine SerumTM is better. It appears that when taken as recommended by the manufacturer that Creatine SerumTM is less effective at enhancing the performance of short burst of exhaustive exercise. The large difference in amount of creatine in a recommended dose of each product almost certainly accounts for the disparity reported in this study.

In the next issue of the Creatine Newsletter I discuss a few other recent studies that examined the chemical composition of certain creatine formulations, including Creatine SerumTM. An understanding of the results from these studies will help us make further sense of the findings presented today.

Scientific Reference

Nicholas D. Gill, Rowan D. Hall and Anthony J. Blazevich (2004) Creatine serum is not as effective as creatine powder for improving cycle sprint performance in competitive male team-sport athletes. Journal of Strength and Conditioning Research Volume 18(2), pages 272 – 275.

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