The purpose of these preliminary data was to observe individual responses to a five-gram dose of oral creatine supplementation. Subjects ingested either 5 grams of creatine in chewable tablet form (CREATEAM™ Chewables) or 5 grams of powder dissolved in warm liquid. The creatine was ingested concurrently with 1 serving of Gatorade mixed with eight ounces of water. Blood samples were collected from the antecubital vein and centrifuged for 10 minutes. All blood was frozen at -80° C until analysis. Approximately 3 ml of serum from each sample was sent to Smith Kline Beecham Laboratories (Waltham Massachusetts) for analysis.

Data are presented in table 1. Subjects 1 and 2 provided samples on three occasions, ingesting either the powder or CREATEAM™ chewable tablets where noted. Subject three ingested only the powder and subject 4 ingested only the CREATEAM™ tablets. All subjects were between 24 and 30 years of age. Subjects 1-3 are male and subject 4 is female. Serum creatine concentration values are presented in m mol/L.

Serum Creatine Concentration in m moles/Lite
	Subject #1				Subject #2				Subj #3	Subj #4
Hrs	CREATEAM™ Tablets			Pwdr	CREATEAM™ Tablets			Pwdr	Pwdr	Tablet
	Test 1	Test 2	Ave. 1 & 2		Test 1	Test 2	Ave. 1 & 2
0	15.26	N/A	15.26	22.89	7.63	N/A	7.63	7.63	15/26	7.63
1	518.84	740.11	629.48	305.20	320.46	671.44	495.95	198.38	228.9	129.71
2	465.43	470.06	467.75	915.60	221.27	526.47	373.87	419.65	198.38
3	N/A		N/A	633.29	N/A	312.83	312.83	244.16	N/A
4	213.64		213.64		N/A		N/A		15.26
5	114.45		114.45		76.3		76.3

Results

Each subject experienced a marked increase in serum creatine concentration compared to baseline measures. The peak creatine concentration obtained following ingestion for all subjects are presented in Figure 1. There is large variation both between and within each subject's acute response to a 5-gram oral dose of creatine monohydrate. Subject 1 experienced the most dramatic increase in serum creatine levels under both conditions. Of the two subjects who participated under both conditions, both experienced a more rapid rise in serum creatine when ingesting the CREATEAM™ chewable tablets, peaking at hour one.

The smallest response was noted in the female subject. Due to the lack o f samples from this subject it is unknown if this is her true peak value, however there is no reason to assume that this subject would not have achieved peak values at one hour as the other subjects had. Thus there may be a gender difference in these initial data.

It is unknown why there are such large variations in serum creatine concentration following a 5-gram dose of oral creatine monohydrate. These values could represent individual differences in absorption in the gastrointestinal tract or transport in the blood. It is unknown how these differences would affect the increased muscle creatine and phosphocreatine levels seen following supplementation.

The above data is from work in progress by E. S. Rawson and P. M. Clarkson, University of Massachusettes, Department of Exercise Science.