from Wikipedia, the free encyclopedia
Structural formula
Structural formula of creatine
Surname Creatine
other names
  • Creatine
  • Creatine (English)
  • N- amidinosarcosine
  • N - (Aminoiminomethyl) - N -methyl-glycine
  • α-methylguanidinoacetic acid
Molecular formula C 4 H 9 N 3 O 2
Brief description

white solid

External identifiers / databases
CAS number
  • 57-00-1 (anhydrous)
  • 6020-87-7 (mono hydrate )
EC number 200-306-6
ECHA InfoCard 100,000,278
PubChem 586
ChemSpider 566
DrugBank DB00148
Wikidata Q223600
Molar mass 131.13 g mol −1
Physical state



1.33 g cm −3 (anhydrous)

Melting point

303 ° C (monohydrate, decomp.)

  • poorly soluble in water (17 g l −1 , monohydrate)
  • almost insoluble in ethanol and diethyl ether (monohydrate)
safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Creatine or creatine (English) (from Greek κρέας kreas , German 'meat' ) is a substance that is found in vertebrates and the like. a. contributes to the supply of the muscles with energy. Creatine is synthesized in the kidneys , the liver and the pancreas , is formally derived from the amino acids glycine , arginine and methionine and is about 90% present in skeletal muscles . Creatine was discovered in 1832 by Eugène Chevreul as an ingredient in meat broth. The German chemist Justus von Liebig identified creatine as a component in the meat of various mammal species in 1847.

In food and intake

Creatine is mainly found in meat and fish in amounts of around 2 to 7 g per kg of food, breast milk and cow's milk contain moderate amounts of creatine, while fruits and vegetables only contain traces of it. In animals, creatine occurs primarily in the skeletal muscles , the heart muscles and the brain , but in smaller quantities in practically all cells of the body. In general, white, glycolytic muscle fibers (sprint muscles) contain more creatine than red, oxidative muscle fibers (endurance muscles). Sausage products have a lower creatine content compared to fresh meat. During the preparation and storage of sausages can be a significant proportion of creatine by the action of heat and storage in a moist environment in the degradation product of creatine in to be converted. The non-enzymatic, spontaneous conversion rate of creatine to creatinine (chemical equilibrium reaction), which takes place particularly in solution, is strongly dependent on the pH value, the temperature and the time. Under favorable circumstances, creatine in an aqueous solution can remain stable for hours to days - but not for months. Therefore, there are no beverages with dissolved creatine on the market.

Since creatine is temperature-sensitive, a certain amount of creatine is also lost when meat is roasted at high temperatures through the conversion into creatinine described above. The highest concentrations of creatine per gram in foods include fresh fish or dried stockfish and fresh or dried meat . (see table below) In humans, too, creatine is mainly stored in the skeletal muscles. The body of a 75 kg adult contains between 120 and 150 g total creatine, i.e. H. of phospho-creatine (PCr, energetically charged form of creatine) plus creatine itself. In the resting body, phospho-creatine and creatine (Cr) are found in a ratio of around ⅔ PCr to ⅓ Cr, mainly in the skeletal muscles, in the heart muscle and in the Brain, but also in smaller quantities in other organs and cells. In the fast, white and predominantly glycolytic muscle fibers z. B. one finds a total creatine concentration of up to 50 mmol / l wet muscle weight or around 125-145 mmol / kg dry muscle mass Synthetic creatine is - just like naturally contained in food - via the intestine into the blood of the hepatic portal vein absorbed and then reaches the consuming organs and tissues via the bloodstream .

Creatine content of various foods (raw state)
Food Creatine content g / kg
herring 6.5-10.0
salmon 4.5
tuna 4.0 and 2.7-6.5, respectively
cod 3.0
plaice 2.0
pork meat 5.0
beef 4.5
milk 0.1
cranberry 0.02


Synthesis of creatine from guanidinoacetate , catalyzed by guanidinoacetate-N-methyltransferase (GAMT)

Creatine is also produced in the human body in amounts of 1 to 2 g per day by the liver , kidneys and pancreas . About half of the daily required amount of creatine of approx. 1.5 to 2 g for adults is mainly produced in the liver from guanidinoacetate. Guanidinoacetate, for its part, is synthesized from the amino acids arginine and glycine by the L- arginine: glycine amidinotransferase (AGAT, EC ) mainly in the kidneys and pancreas. For the methylation of guanidinoacetate, the enzyme guanidinoacetate N -methyl transferase ( GAMT , EC ) and an activated form of the amino acid methionine , S- adenosyl methionine ( SAM ), are required. The latter reaction (see reaction scheme opposite) takes place mainly in the liver. Although the amino acids arginine, glycine and methionine are needed for the synthesis of creatine, creatine itself is not an amino acid, but a so-called guanidinium compound with a central carbon to which three nitrogen atoms are bound. The creatine produced in the body passes from the liver into the blood and from there to the target organs, e.g. B. skeletal muscles, heart muscle, brain, nerves, retina of the eye etc.

Chemical stability

Creatine can be stored for several years at room temperature and in a dry place. Instabilities show up when creatine is dissolved in water. The degree of creatine disintegration in aqueous solutions does not depend on the concentration, but on the pH value . In general, the lower the pH and the higher the temperature, the faster the breakdown. Creatine is relatively stable in solutions with neutral pH (6.5 to 7.5). A decrease in pH results in an increased rate of disintegration. When stored at temperatures of 25 degrees, creatine breaks down significantly after three days: 4% at a pH value of 5.5, 12% at a pH value of 4.5 and 21% at a pH value of 3.5 . In aqueous solutions, creatine breaks down to creatinine during storage at room temperature within several days , while the breakdown is reduced when refrigerated. So if creatine is not consumed directly after it has been dissolved in water or other drinkable solutions, it should be stored at low temperatures to counteract its breakdown. The breakdown of creatine can also be reduced or even stopped if the pH value is either reduced below 2.5 or if the pH value is increased. A very high pH value results in the deprotonation of the carboxylic acid group to the carboxylate , the reactivity of which towards nucleophiles is reduced compared to the carboxylic acid group . As a result, the decay process is slowed down by making the intramolecular cyclization more difficult. A very low pH value (below 2.5) leads to protonation of the guanidine functionality of the creatine molecule and thus to a decrease in its nucleophilicity . The consequence of this is that the intramolecular cyclization to creatinine is avoided. This effect also takes place under the acidic conditions in the stomach, which is why the breakdown into creatinine is halted. The conversion of creatine to creatinine in the gastrointestinal tract is therefore minimal, regardless of the intake time.

Physiological importance

Functions and effects in the human body

Structural formula of creatine phosphate

Creatine in the form of creatine phosphate (also phosphocreatine , PCr ) is required primarily for muscle contraction , but also for brain and nerve function . Creatine phosphate provides the phosphoryl group that is used to convert the adenosine diphosphate ( ADP ) formed during contraction back into adenosine triphosphate ( ATP ). In resting cells, around 60% of creatine occurs as phosphocreatine (energy source) and 40% as free creatine (energy precursor). The amount of creatine stored in the human body is 120 to 150 g in an adult, around 1.5–2% of total creatine is excreted as creatinine per day via the kidneys with the urine. This does not apply to sausages where the majority of the creatine has been broken down to creatinine through processing and storage; z. For example, when curing and drying a ham, around 75% of its creatine is lost during the first ten months (raw ham).

Creatine is necessary for the normal development of the human body and an optimal function of the body organs (muscles, brain, nerves, visual and hearing processes as well as reproduction). A supplementation with creatine can in terms of modified food (stress, high performance) and nutritional conditions make sense and displayed.

Creatine is necessary for the normal development of the organism, especially the brain during embryonic development and the early childhood phase, as well as for the normal physiological function of muscles and other body organs. Experimental animals in which the creatine content in muscles and brain was reduced by feeding a creatine analogue (β-guanidinyl propionic acid, GPA ) show clear pathological disorders in muscle and brain functions. In addition, transgenic test animals that no longer express creatine kinase (CK) show serious pathophysiological phenotypes, depending on which of the four creatine kinase isoforms is missing in the muscles and / or the brain.

People with creatine deficiency syndrome , with genetic defects either in the two enzymes involved in endogenous creatine synthesis ( AGAT and GAMT ) or in the creatine transporter , the protein that transports creatine to target cells, show severe neurological and neuromuscular problems pathological disorders, e.g. B. poorly developed muscles, developmental disorders, inability to learn to speak, epilepsy , autism , intellectual disabilities. This proves that a sufficient supply of creatine to the organism, together with the presence of creatine kinase, is essential for the normal development and function of the body organs.

Creatine requirement with a low-meat and meat-free diet

Vegetarians and elderly people who eat little or no meat can ingest small amounts of creatine (a maximum of 20% of the creatine ingested from mixed diets) with dairy products. Babies laying on soy are fed-based milk substitute, take just as vegans to no creatine in the diet. These groups of people have a significantly lower creatine content in the blood plasma than omnivores and synthesize their creatine requirements themselves. Older people can often have a low intake of essential amino acids and vitamin B 12 , which are required for creatine synthesis.

Therapeutic use

In medicine , creatine is used as an auxiliary therapy in the treatment of various muscle diseases such as B. used in muscular dystrophy to improve muscle growth and muscle strength. A number of animal and clinical studies with patients with various neuro-muscular and neuro-degenerative diseases such as: B. Parkinson's or Huntington's disease and amyotrophic lateral sclerosis (ALS) have shown the potential of creatine as a valuable additional therapy. Further clinical trials with larger patient numbers are being conducted primarily in the United States.

Creatine in Sports

Opportunities to increase performance through creatine supplementation

A healthy body produces many of the substances necessary for the maintenance of the body's functionality itself or takes in sufficient amounts with a balanced diet. Nevertheless, the additional intake of creatine has proven to be useful or at least not disadvantageous in a few sports. However, the amounts of additional intake, which are often given very high, should be questioned. After all, the intake of 5 g of creatine corresponds to the intake of 1.1 kg of raw beef.

Creatine supplementation has been shown to be effective both for increasing short-term performance and increasing maximum muscle strength, for example in weightlifting or sprinting, and for reducing cell damage in endurance sports such as marathons. This can also increase the training volume. In contrast to carnitine , for example , creatine is absorbed by the muscles, and phosphorylation of the creatine absorbed in this way increases the phospho-creatine (PCr) concentration and thus also the ratio of PCr / ATP, which improves the cellular energy status of the muscles. A 2006 study showed that creatine supplementation combined with strength training can increase exercise-induced increases in the number of satellite cells and myonuclei in human skeletal muscles, resulting in increased muscle fiber growth. This growth of the glycolytic, fast type II fibers and the oxidative, slow type I fibers is accompanied by an increase in muscle strength, which affects both the sprint and endurance fibers .

The European Food Safety Authority (EFSA) has officially recognized so-called health claims in a declaration for creatine, in contrast to most other dietary supplements . Put simply, these accepted health claims for creatine state that creatine supplementation leads to an increase in muscle mass and muscle strength as well as muscle performance, especially during very intense and repetitive activities. A daily intake of 3 g creatine is specified as a condition for use to increase performance.

In an official position paper of the International Society for Sports Nutrition by an international panel of experts, these and other advantages of creatine supplementation are listed based on a large number of scientific publications.

In order to renew the reserves of the energy carrier ATP, the muscles mainly use phospho-creatine (synonym creatine phosphate), especially in the first minute of activity. The nutritionist Andreas Hahn from the University of Hanover judges in his book Dietary Supplements:

“The possible meaning of creatine gifts relates exclusively to people with vigorous sporting activities that are pursued with great zeal. Due to conflicting study results, however, supplementation with creatine cannot be recommended. A short-term supplementation of creatine (up to 8 weeks) in amounts of about 20 g / day in the first week and 3 g / day in the maintenance phase is considered harmless. "

Continuous supplementation (taking creatine over a longer period of time) is also considered harmless today. After a period of four weeks after the end of creatine supplementation, the muscular content falls back to the initial value.

Great leaps in performance, as they are often advertised in exaggerated proportions by the supplement industry for food supplements , are not to be expected from supplementation with creatine. Particularly in strength training, the main focus should be on the greatest possible training intensity as well as the higher training cadence observed and published by many athletes and better recovery and nutrition.

Side effects of creatine supplementation

In individual cases and practically only during the normally unnecessary high dose phase (4 × 5 g creatine, i.e. a total of 20 g creatine per day for 7 to 10 days), creatine can lead to flatulence or mild diarrhea . Occasionally, users react with muscle cramps . However, scientific studies with a large number of athletes show that these side effects are largely based on unverified individual observations and that creatine does not cause significant gas, muscle cramps or injury. During the high dose phase, there may also be a weight gain of 1 to 3 kg. This is mainly due to water retention, because sodium and chloride ions simultaneously enter the cell with the creatine via the creatine transporter, which then leads to water retention . Gradually, the increased water uptake in the muscles due to osmotic effects normalizes , and there is an effective increase in muscle mass in the course of creatine supplementation, which is accompanied by a 10 to 20 percent increase in muscle strength.

The European Food Safety Authority (EFSA) published an opinion in 2004, according to which a daily intake of 3 g creatine is risk-free, provided the creatine ingested - especially with regard to contamination with dicyandiamide and dihydro-1,3,5-triazine derivatives and heavy metals - of sufficient purity (at least 99.95%). The alleged harmfulness of creatine to the kidneys, which has been mentioned again and again in the press, began in 1998 and is based on data from a case study in which creatine supplementation negatively affected the glomerular filtration rate of the kidney in a 25-year-old man who had previously suffered a disease kidney function suffered. A few days later, the French sports magazine L'Équipe spread the information that creatine supplementation was generally harmful to the kidneys. Various European media picked up the news and reported the same thing. The influence of creatine supplementation on clinical parameters, in particular those relating to liver and kidney function, has since been investigated in large-scale studies, with no negative effects being found. A comparative study published in 2008 by the University of Munich examined the blood and urine of 60 elderly Parkinson's patients over a period of two years. 40 patients received a creatine supplement with a daily dose of 4 g, the other 20 a placebo . Although there was an increase in serum creatine in the creatine group, all other markers of tubular or glomerular kidney function remained normal, suggesting unchanged kidney function. Gastrointestinal complaints were the main undesirable effects. The 2011 review by Kim et al. recommends that daily doses> 3–5 g should not be consumed by people with already impaired kidney function or at risk of it (given for example in diabetes mellitus, high blood pressure and reduced glomerular filtration rate ).

At this point it should be pointed out that the kidneys themselves need phospho-creatine and creatine for their normal function and accordingly also express the enzyme creatine kinase. In addition, the first of the two endogenous synthesis steps for the production of the body's own creatine takes place in the kidneys. Thus, the repeatedly wrongly cited danger of creatine for the kidneys can be clearly denied. On the contrary, since kidney patients and dialysis patients have less total body creatine, because 1) the diseased kidney can contribute less to the endogenous creatine synthesis, 2) because chronically dialyzed patients lose their own creatine through leaching and 3) dialysis patients consume little fish and meat and thus have a nutritional deficiency of creatine, it has recently been suggested to supplement these creatine-depleted patients with creatine so that the body's own pools of creatine in muscles, heart and brain would normalize again and the patients feel stronger and less tired and depressed , d. that is, their quality of life would be significantly improved.

An article by the Mayo Clinic from 2013 pointed out possible side effects and adverse interactions (e.g. with caffeine ) and also referred to the advice of the American health authority FDA to consult a doctor before use.


Web links

Wikibooks: Creatine Phosphate Biosynthesis  - Learning and Teaching Materials

Individual evidence

  1. a b Datasheet Creatine, anhydrous at AlfaAesar, accessed on October 24, 2019 ( PDF )(JavaScript required) .
  2. a b c Entry on creatine. In: Römpp Online . Georg Thieme Verlag, accessed on June 16, 2014.
  3. a b Creatine anhydrous data sheet from Sigma-Aldrich , accessed on October 24, 2019 ( PDF ).
  4. MS Bahrke, C. Yesalis (Ed.): Performance-Enhancing Substances in Sport and Exercise. Human Kinetics, 2002, ISBN 0-7360-3679-2 , p. 175. ( limited preview in Google book search).
  5. ^ A b Hans-Konrad Biesalski (ed.): Nutritional medicine: according to the nutritional medicine curriculum of the German Medical Association. Georg Thieme Verlag, 2004 ISBN 3-13-100293-X , p. 236. ( limited preview in Google book search).
  6. Creatine intake through food [increase creatine level naturally]. (No longer available online.) In: Kevin Thomaser, archived from the original on March 4, 2016 ; accessed on November 10, 2015 .
  7. E. Hultman, K. Söderlund, JA Timmons, G. Cederblad, PL Greenhaff: Muscle creatine loading in men. In: Journal of applied physiology. Volume 81, Number 1, July 1996, pp. 232-237, doi: 10.1152 / jappl.1996.81.1.232 , PMID 8828669 .
  8. a b Creatine in swimming ( Memento of December 12, 2011 in the Internet Archive ) by Felix Gmünder, Zurich; Retrieved November 8, 2011.
  9. Markus Wyss, Olivier Braissant, Ivo Pischel, Gajja S. Salomons, Andreas Schulze, Sylvia Stockler, Theo Wallimann: Creatine and Creatine Kinase in Health and Disease - A Bright Future Ahead? In: Subcellular Biochemistry. 2008, Volume 46, pp. 309–334, doi : 10.1007 / 978-1-4020-6486-9_16
  10. a b T. Wallimann : More energy - more output Creatine - why, when and for whom? (PDF; 1.1 MB) In: Swiss Journal for Nutritional Medicine. Number 5, 2008.
  11. ^ R. Jäger, M. Purpura, A. Shao, T. Inoue, RB Kreider: Analysis of the efficacy, safety, and regulatory status of novel forms of creatine. In: Amino acids. Volume 40, number 5, May 2011, pp. 1369-1383, doi: 10.1007 / s00726-011-0874-6 , PMID 21424716 , PMC 3080578 (free full text) (review).
  12. T. Wallimann, M. Tokarska-Schlattner, D. Neumann u. a .: The Phosphocreatine Circuit: Molecular and Cellular Physiology of Creatine Kinases, Sensitivity to Free Radicals, and Enhancement by Creatine Supplementation. In: Molecular System Bioenergetics: Energy for Life. November 22, 2007. doi: 10.1002 / 9783527621095.ch7 C
  13. a b R. H. Andres, AD Ducray u. a .: Functions and effects of creatine in the central nervous system. In: Brain research bulletin. Volume 76, Number 4, July 2008, pp. 329-343, doi: 10.1016 / j.brainresbull.2008.02.035 . PMID 18502307 . (Review).
  14. a b T. Wallimann, M. Wyss u. a .: Intracellular compartment, structure and function of creatine kinase isoenzymes in tissues with high and fluctuating energy demands: the 'phosphocreatine circuit' for cellular energy homeostasis. In: Biochemical Journal . Volume 281 (Pt 1), January 1992, pp. 21-40, PMID 1731757 . PMC 1130636 (free full text). (Review).
  15. N Marušić, MC Aristoy, F Toldrá: Nutritional pork meat compounds as affected by dry ham-curing . In: Meat Sci. , 2012 Aug 8. E-pub, PMID 22910804
  16. ^ A b M. Wyss, T. Wallimann: Creatine metabolism and the consequences of creatine depletion in muscle. In: Molecular and cellular biochemistry. Volume 133-134, 1994, pp. 51-66, doi: 10.1007 / BF01267947 . PMID 7808465 . (Review).
  17. ^ A b T. Wallimann, M. Tokarska-Schlattner, U. Schlattner: The creatine kinase system and pleiotropic effects of creatine. In: Amino acids. Volume 40, Number 5, May 2011, pp. 1271-1296, doi: 10.1007 / s00726-011-0877-3 . PMID 21448658 . PMC 3080659 (free full text). (Review).
  18. ^ HJ in 't Zandt, B. Wieringa, A. Heerschap: Creatine kinase knockout mice - what is the phenotype: skeletal muscle. In: Magma. Volume 6, Number 2-3, September 1998, pp. 122-123, doi: 10.1007 / BF02660929 . PMID 9803381 .
  19. F. Streijger, F. Oerlemans u. a .: Structural and behavioral consequences of double deficiency for creatine kinases BCK and UbCKmit. In: Behavioral brain research. Volume 157, Number 2, February 2005, pp. 219-234, doi: 10.1016 / j.bbr.2004.07.002 . PMID 15639173 .
  20. A. Schulze: Creatine deficiency syndromes. In: Molecular and cellular biochemistry. Volume 244, number 1-2, February 2003, pp. 143-150, doi: 10.1023 / A: 1022443503883 . PMID 12701824 . (Review).
  21. a b J. T. Brosnan, RP da Silva, ME Brosnan: The metabolic burden of creatine synthesis. In: Amino acids. Volume 40, Number 5, May 2011, pp. 1325-1331, doi: 10.1007 / s00726-011-0853-y , PMID 21387089 (review).
  22. ^ ME Brosnan, JT Brosnan: The role of dietary creatine. In: Amino acids. Volume 48, Number 8, August 2016, pp. 1785-1791, doi: 10.1007 / s00726-016-2188-1 , PMID 26874700 (review).
  23. A. Shomrat, Y. Weinstein, A. Katz: Effect of creatine feeding on maximal exercise performance in vegetarians. In: European journal of applied physiology. Volume 82, Number 4, July 2000, pp. 321-325, doi: 10.1007 / s004210000222 . PMID 10958375 .
  24. ^ T. Wallimann: Creatine in general medicine. (PDF; 82 kB) In: ARS MEDICI DOSSIER. VII + VIII, 2009, pp. 28-31.
  25. ^ RA Kley, MA Tarnopolsky, M. Vorgerd: Creatine for treating muscle disorders. In: Cochrane database of systematic reviews (online). Number 2, 2011, S. CD004760, doi: 10.1002 / 14651858.CD004760.pub3 . PMID 21328269 . (Review).
  26. a b T. Wallimann: Introduction-creatine: cheap ergogenic supplement with great potential for health and disease. In: Sub-cellular biochemistry. Volume 46, 2007, pp. 1-16, PMID 18652069 .
  27. J. Weineck: Sports biology. Edition 9, Spitta Verlag, 2004, ISBN 3-934211-83-6 , p. 649f limited preview in the Google book search
  28. M. Hadjicharalambous, LP Kilduff, YP Pitsiladis: Brain serotonin and dopamine modulators, perceptual responses and endurance performance during exercise in the heat following creatine supplementation. In: Journal of the International Society of Sports Nutrition. Volume 5, 2008, p. 14, doi: 10.1186 / 1550-2783-5-14 . PMID 18826587 . PMC 2570654 (free full text).
  29. RV Santos, RA Bassit u. a .: The effect of creatine supplementation upon inflammatory and muscle soreness markers after a 30km race. In: Life sciences . Volume 75, number 16, September 2004, pp. 1917-1924, doi: 10.1016 / j.lfs.2003.11.036 . PMID 15306159 .
  30. DG Burke, PD Chili Beck u. a .: Effect of creatine and weight training on muscle creatine and performance in vegetarians. In: Medicine and science in sports and exercise. Volume 35, Number 11, November 2003, pp. 1946-1955, doi: 10.1249 / 01.MSS.0000093614.17517.79 . PMID 14600563 .
  31. K. Vandenberghe, M. Goris u. a .: Long-term creatine intake is beneficial to muscle performance during resistance training. In: Journal of applied physiology (Bethesda, Md .: 1985). Volume 83, Number 6, December 1997, pp. 2055-2063, PMID 9390981 .
  32. S. Olsen, P. Aagaard et al. a .: Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training. In: The Journal of Physiology . Volume 573, Pt 2 June 2006, pp. 525-534, doi: 10.1113 / jphysiol.2006.107359 . PMID 16581862 . PMC 1779717 (free full text).
  33. JS Volek, WJ Kraemer u. a .: Creatine supplementation enhances muscular performance during high-intensity resistance exercise. In: Journal of the American Dietetic Association. Volume 97, Number 7, July 1997, pp. 765-770, doi: 10.1016 / S0002-8223 (97) 00189-2 . PMID 9216554 .
  34. P. Hespel, W. Derave: Ergogenic effects of creatine in sports and rehabilitation. In: Sub-cellular biochemistry. Volume 46, 2007, pp. 245-259, PMID 18652080 . (Review).
  35. EFSA Panel on Dietetic Products, Nutrition and Allergies: Scientific Opinion on the substantiation of health claims related to creatine and increase in physical performance during short-term, high intensity, repeated exercise bouts (ID 739, 1520, 1521, 1522, 1523, 1525, 1526, 1531, 1532, 1533, 1534, 1922, 1923, 1924), increase in endurance capacity (ID 1527, 1535), and increase in endurance performance (ID 1521, 1963) pursuant to Article 13 (1) of Regulation (EC) No 1924/2006. In: EFSA Journal. Volume 9, number 7, 2011, p. 2303, (24 p.), Doi: 10.2903 / j.efsa.2011.2303
  36. REGULATION (EU) No. 432/2012 OF THE COMMISSION of May 16, 2012, p. L 136/15 ( Memento of the original of August 21, 2015 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF) @1@ 2Template: Webachiv / IABot /
  37. TW Buford, RB Kreider u. a .: International Society of Sports Nutrition position stand: creatine supplementation and exercise. In: Journal of the International Society of Sports Nutrition. Volume 4, 2007, p. 6, doi: 10.1186 / 1550-2783-4-6 . PMID 17908288 . PMC 2048496 (free full text).
  38. Jeremy M. Berg, John L. Tymoczko, Lubert Stryer : Biochemistry. 6th edition. Spectrum Akademischer Verlag, Heidelberg 2007, ISBN 978-3-8274-1800-5 . (Free full text access to the 5th edition) .
  39. M. Greenwood, RB Kreider et al. a .: Creatine supplementation during college football training does not increase the incidence of cramping or injury. In: Molecular and cellular biochemistry. Volume 244, Number 1-2, February 2003, pp. 83-88, PMID 12701814 .
  40. M. Greenwood, RB Kreider et al. a .: Cramping and Injury Incidence in Collegiate Football Players Are Reduced by Creatine Supplementation. In: Journal of athletic training. Volume 38, Number 3, September 2003, pp. 216-219, PMID 14608430 . PMC 233174 (free full text).
  41. TW Buford, RB Kreider u. a .: International Society of Sports Nutrition position stand: creatine supplementation and exercise. In: Journal of the International Society of Sports Nutrition. Volume 4, 2007, p. 6, doi: 10.1186 / 1550-2783-4-6 , PMID 17908288 , PMC 2048496 (free full text).
  42. Opinion of the Scientific Panel on Food Additives, Flavors, Processing Aids and Materials in Contact with Food on a request from the Commission related to Creatine monohydrate for use in foods for particular nutritional uses. In: The EFSA Journal. Volume 36, 2004, pp. 1-6. doi: 10.2903 / j.efsa.2004.36
  43. NR Pritchard, PA Kalra: Renal dysfunction accompanying oral creatine supplements. In: The Lancet. Volume 351, Number 9111, April 25, 1998, pp. 1252-1253.
  44. La creatine dangereuse? In: L'Equipe , April 10, 1998.
  45. RB Kreider, C. Melton et al. a .: Long-term creatine supplementation does not significantly affect clinical markers of health in athletes. In: Molecular and cellular biochemistry. Volume 244, Number 1-2, February 2003, pp. 95-104, PMID 12701816 .
  46. T. Wallimann, M. Möddel u. a .: Creatine and kidney function: Pure creatine is not harmful to the kidneys. In: Swiss Med Forum (SMF). Volume 13, number 42, 2013, pp. 848–850, (PDF)
  47. A. Bender, W. Samtleben, M. Elstner et al .: Long-term creatine supplementation is safe in aged patients with Parkinson disease. In: Nutrition Research. Volume 28, Number 3, 2008, pp. 172-178. PMID 19083405 .
  48. ^ HJ Kim, CK Kim, A. Carpentier, JR Poortmans: Studies on the safety of creatine supplementation. In: Amino Acids. 2011 May; 40 (5): 1409-18. doi: 10.1007 / s00726-011-0878-2 , PMID 21399917 .
  49. ML.Guerrero, J.Beron, B.Spindler, P.Grosscurth, T.Wallimann and F.Verrey. Metabolic support of Na + pump in apically permeabilized A6 kidney cell epithelia: role of creatine kinase. In: Am J Physiol. 1997 Feb; 272 (2 pt 1): C697-706. doi: 10.1152 / ajpcell.1997.272.2.C697 , PMID 9124314 .
  50. T. Wallimann, U. Riek, MM Möddel: Intradialytic creatine supplementation: A scientific rationale for improving the health and quality of life of dialysis patients. In: Medical Hypotheses , 2017 Feb, 99, pp. 1–14. doi: 10.1016 / j.mehy.2016.12.002 , PMID 28110688 .
  51. Creatine Safety - Drugs and supplements. Mayo Clinic; accessed June 8, 2014.