Creatine Drug Interactions, Uses, Effectiveness, Safety & More

Despite two case reports describing hepatic injury in patients taking creatine, meta-analyses and clinical studies specifically evaluating the safety of creatine have not identified an increased risk for hepatic injury. In addition, population research suggests that there is not an association between creatine intake and liver fibrosis, cirrhosis, or hepatic steatosis. However, this study largely included subjects consuming less than 4 grams daily.

One preliminary clinical trial specifically evaluated the effect of creatine loading and maintenance doses on hepatic function indices in healthy adults. No clinically significant changes in hepatic indices were reported in patients taking creatine loading doses of 20 grams daily for 5 days followed by maintenance doses of 3 grams daily for 8 weeks. Another clinical study evaluated the impact of creatine monohydrate and creatine nitrate on liver function enzymes, showing no change in levels within 5 hours after the first dose of 12 grams or after continued consumption of 12 grams daily for 7 days followed by 3 grams daily for 21 days. The patients that experienced hepatic injury in the available case reports were also taking other exercise supplements. Whether the reported adverse hepatic effects were due to creatine or the other supplements patients were taking is unclear. Also, neither of these case reports addressed whether the supplements were tested for contamination.

1. Whitt, K. N., Ward, S. C., Deniz, K., Liu, L., Odin, J. A., and Qin, L. Cholestatic liver injury associated with whey protein and creatine supplements. Semin.Liver Dis. 2008;28(2):226-231.
2. Vilella AL, Limsuwat C, Williams DR, Seifert CF. Cholestatic jaundice as a result of combination designer supplement ingestion. Ann Pharmacother 2013;47(7-8):e33.
3. de Guingand DL, Palmer KR, Snow RJ, Davies-Tuck ML, Ellery SJ. Risk of adverse outcomes in females taking oral creatine monohydrate: a systematic review and meta-analysis. Nutrients. 2020;12(6):E1780.
4. Almeida D, Colombini A, Machado M. Creatine supplementation improves performance, but is it safe? Double-blind placebo-controlled study. J Sports Med Phys Fitness. 2020;60(7):1034-9.
5. Todorovic N, Korovljev D, Stajer V, Jorga J, Ostojic SM. Creatine consumption and liver disease manifestations in individuals aged 12?years and over. Food Sci Nutr 2022;11(2):1134-1141.
6. Robinson, T. M., Sewell, D. A., Casey, A., Steenge, G., and Greenhaff, P. L. Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function. Br.J Sports Med 2000;34(4):284-288.
7. Galvan E, Walker Dk, Simbo SY, et al. Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance. J Int Soc Sports Nutr. 2016 Mar 31;13:12.

Some research suggests that creatine supplementation can cause edema. In a randomized controlled trial, 26% of patients with amyotrophic lateral sclerosis (ALS) receiving creatine 10 grams daily reported edema after 2 months of treatment compared to 9% with placebo. The difference between groups was statistically significant at 2 months but not at month 4 and beyond. Creatine is believed to cause slight water retention, which may have been more apparent in patients who were immobilized due to ALS. While this adverse drug reaction did not lead to worsening cardiac function in these patients, theoretically, creatine-related water retention could worsen congestive heart failure or hypertension.

There is one case report of lone atrial fibrillation in a 30-year-old male vegetarian. He started powdered creatine 20 grams daily for 5 days, followed by 2.5 grams daily for a month. However, he discontinued powdered creatine due to severe cramping and diarrhea, and reinitiated creatine supplementation a month later with an encapsulated formulation. Aside from gelatin in the capsule, creatine was the only ingredient listed in both formulations. During the loading dose phase, the patient developed dyspnea and palpitations and was diagnosed with lone atrial fibrillation in the emergency department. Symptoms resolved with treatment and supplement discontinuation. Theoretically, alterations in electrolyte balance due to dehydration or diarrhea could lead to conduction abnormalities and arrhythmia; however, in this case, the patient had normal electrolyte levels. Contaminants in dietary supplements might also be responsible for adverse reactions; this specific creatine product was not tested for contaminants. It remains unclear whether creatine was associated with this event.

Theoretically, taking creatine nitrate might reduce blood pressure and heart rate due to its nitrate component. However, clinical research shows that creatine nitrate 12 grams daily for 7 days followed by 3 grams daily for 21 days does not lower blood pressure or heart rate acutely or chronically when compared to creatine monohydrate or placebo.

1. Groeneveld, G. J., Beijer, C., Veldink, J. H., Kalmijn, S., Wokke, J. H., and van den Berg, L. H. Few adverse effects of long-term creatine supplementation in a placebo-controlled trial. Int J Sports Med 2005;26(4):307-313.
2. Kammer RT. Lone atrial fibrillation associated with creatine monohydrate supplementation. Pharmacotherapy 2005;25:762-4.
3. Galvan E, Walker Dk, Simbo SY, et al. Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance. J Int Soc Sports Nutr. 2016 Mar 31;13:12.

Anxiety, irritability, depression, aggression, and nervousness have been reported in clinical research for patients taking creatine, although the effects are not common. A case of acute organic psychosis was reported in a 32-year-old soldier in Iraq who was consuming excessive amounts of caffeine coupled with use of creatine (Creatamax, MaxiNutrition) one tablet twice daily for 3 weeks plus a specific stimulant containing bitter orange, guarana seed extract, and St. John's wort extract (Ripped Fuel Ephedra Free, Twinlabs) two tablets three times daily for 2 days prior to admission. The psychosis was considered likely due to caffeine consumption in combination with the stimulant supplement rather than creatine.

1. Volek, J. S., Duncan, N. D., Mazzetti, S. A., Putukian, M., Gomez, A. L., and Kraemer, W. J. No effect of heavy resistance training and creatine supplementation on blood lipids. Int J Sport Nutr.Exerc.Metab 2000;10(2):144-156.
2. Boos, C. J., White, S. H., Bland, S. A., and McAllister, P. D. Dietary supplements and military operations: caution is advised. J R.Army Med Corps 2010;156(1):41-43.

Population research shows that use of muscle building supplements such as creatine, protein, and androstenedione is associated with an increased odds of testicular germ cell cancer. This risk appears to be more apparent in early users, those using two or more muscle building supplements, and those with long-term use of the supplements. The odds of testicular germ cell cancer may be increased by up to 155% in males taking both creatine and protein supplements. The risk of testicular germ cell cancer from creatine alone is unclear from this study.

1. Li N, Hauser R, Holford T, et al. Muscle-building supplement use and increased risk of testicular germ cell cancer in men from Connecticut and Massachusetts. Br J Cancer 2015;112(7):1247-50.

In clinical research, thirst, sleepiness, mild headache, and syncope have been reported for patients taking creatine, although the events were uncommon. More serious adverse events have been reported for patients taking creatine in combination with other ingredients. A case of ischemic stroke has been reported for an athlete who consumed creatine monohydrate 6 grams, caffeine 400-600 mg, ephedra 40-60 mg, and a variety of other supplements daily for 6 weeks. In another case, a 26 year old male reported with a hemorrhagic stroke linked to taking the supplement Jack3d, which contains creatine, DMAA, schizandrol A, caffeine, beta-alanine, and L-arginine alpha-ketoglutarate. It is likely that these adverse events were due to other ingredients, such as caffeine, ephedra, and DMAA, which are known to have stimulant and vasoconstrictive properties.

1. Kilduff, L. P., Vidakovic, P., Cooney, G., Twycross-Lewis, R., Amuna, P., Parker, M., Paul, L., and Pitsiladis, Y. P. Effects of creatine on isometric bench-press performance in resistance-trained humans. Med Sci.Sports Exerc. 2002;34(7):1176-1183.
2. Volek, J. S., Ratamess, N. A., Rubin, M. R., Gomez, A. L., French, D. N., McGuigan, M. M., Scheett, T. P., Sharman, M. J., Hakkinen, K., and Kraemer, W. J. The effects of creatine supplementation on muscular performance and body composition responses to
3. Vandebuerie, F., Vanden Eynde, B., Vandenberghe, K., and Hespel, P. Effect of creatine loading on endurance capacity and sprint power in cyclists. Int J Sports Med 1998;19(7):490-495.
4. Vahedi K, Domingo V, Amarenco P, Bousser MG. Ischemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for bodybuilding. J Neurol Neurosurg Psychiatr 2000;68:112-3.
5. Young C, Oladipo O, Frasier S, et al. Hemorrhagic stroke in young healthy male following use of sports supplement Jack3d. Mil Med 2012;177(12):1450-4.

Some small clinical studies have reported diarrhea and vomiting with oral creatine supplementation. Also, gastrointestinal distress, transient abdominal discomfort, constipation, heartburn, and nausea have been reported by a small number of individuals in randomized, controlled clinical trials,. However, most high-quality clinical research shows that creatine does not increase the incidence of gastrointestinal upset.

Undissolved creatine powder may cause gastroenteritis. Additionally, simultaneous intake of creatine and caffeine powder may increase the occurrence of gastrointestinal distress.

1. Juhn MS, O'Kane JW, Vinci DM. Oral creatine supplementation in male collegiate athletes: a survey of dosing habits and side effects. J Am Diet Assoc 1999;99:593-5.
2. Groeneveld GJ, Veldink JH, van der Tweel I, et al. A randomized sequential trial of creatine in amyotrophic lateral sclerosis. Ann Neurol 2003;53:437-45. .
3. Chrusch, M. J., Chilibeck, P. D., Chad, K. E., Davison, K. S., and Burke, D. G. Creatine supplementation combined with resistance training in older men. Med Sci.Sports Exerc. 2001;33(12):2111-2117.
4. Cramer, J. T., Stout, J. R., Culbertson, J. Y., and Egan, A. D. Effects of creatine supplementation and three days of resistance training on muscle strength, power output, and neuromuscular function. J Strength.Cond.Res 2007;21(3):668-677.
5. Ostojic, S. M. and Ahmetovic, Z. Gastrointestinal distress after creatine supplementation in athletes: are side effects dose dependent? Res.Sports Med. 2008;16(1):15-22.
6. Koenig CA, Benardot D Cody M Thompson WR. Comparison of creatine monohydrate and carbohydrate supplementation on repeated jump height performance. J Strength Cond Res. 2008;22(4):1081-1086.
7. Chilibeck PD, Candow DG, Landeryou T, Kaviani M, Paus-Jenssen L. Effects of creatine and resistance training on bone health in postmenopausal women. Med Sci Sports Exerc. 2015;47(8):1587-95.
8. Rawson ES, Wehnert ML, Clarkson PM. Effects of 30 days of creatine ingestion in older men. Eur J Appl Physiol Occup Physiol 1999;80:139-44.
9. Tarnopolsky, M. A. Potential benefits of creatine monohydrate supplementation in the elderly. Curr.Opin.Clin Nutr.Metab Care 2000;3(6):497-502.
10. Tarnopolsky, M. A. and MacLennan, D. P. Creatine monohydrate supplementation enhances high-intensity exercise performance in males and females. Int J Sport Nutr.Exerc.Metab 2000;10(4):452-463.
11. Cox, G., Mujika, I., Tumilty, D., and Burke, L. Acute creatine supplementation and performance during a field test simulating match play in elite female soccer players. Int J Sport Nutr.Exerc.Metab 2002;12(1):33-46.
12. Brose, A., Parise, G., and Tarnopolsky, M. A. Creatine supplementation enhances isometric strength and body composition improvements following strength exercise training in older adults. J Gerontol A Biol.Sci.Med Sci. 2003;58(1):11-19.
13. Tyler, T. F., Nicholas, S. J., Hershman, E. B., Glace, B. W., Mullaney, M. J., and McHugh, M. P. The effect of creatine supplementation on strength recovery after anterior cruciate ligament (ACL) reconstruction: a randomized, placebo-controlled, double-b
14. Astorino, T. A., Marrocco, A. C., Gross, S. M., Johnson, D. L., Brazil, C. M., Icenhower, M. E., and Kneessi, R. J. Is running performance enhanced with creatine serum ingestion? J Strength.Cond.Res 2005;19(4):730-734.
15. Young, P., De, Jonghe P., Stogbauer, F., and Butterfass-Bahloul, T. Treatment for Charcot-Marie-Tooth disease. Cochrane.Database.Syst.Rev. 2008;(1):CD006052.
16. Gufford, B. T., Sriraghavan, K., Miller, N. J., Miller, D. W., Gu, X., Vennerstrom, J. L., and Robinson, D. H. Physicochemical characterization of creatine N-methylguanidinium salts. J.Diet.Suppl 2010;7(3):240-252.
17. Wilkinson TJ, Lemmy AB, Jones AG, et al. Can creatine supplementation improve body composition and objective physical function in Rheumatoid Arthritis patients? A randomized controlled trial. Arthritis Care Res (Hoboken). 2016 Jun;68(6):729-37.
18. Mills S, Candow DG, Forbes SC, Neary JP, Ormsbee MJ, Antonio J. Effects of creatine supplementation during resistance training sessions in physically active young adults. Nutrients. 2020;12(6):1880.
19. Whinton AK, Donahoe K, Gao R, et al. Repeated application of a novel creatine cream improves muscular peak and average power in male subjects. J Strength Cond Res. 2020;34(9):2482-2491.
20. Forbes SC, Candow DG, Ostojic SM, Roberts MD, Chilibeck PD. Meta-analysis examining the importance of creatine ingestion strategies on lean tissue mass and strength in older adults. Nutrients 2021;13(6):1912.
21. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creating supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18.
22. de Guingand DL, Palmer KR, Snow RJ, Davies-Tuck ML, Ellery SJ. Risk of adverse outcomes in females taking oral creatine monohydrate: a systematic review and meta-analysis. Nutrients. 2020;12(6):E1780.
23. Almeida D, Colombini A, Machado M. Creatine supplementation improves performance, but is it safe? Double-blind placebo-controlled study. J Sports Med Phys Fitness. 2020;60(7):1034-9.
24. Greenhaff P. Renal dysfunction accompanying oral creatine supplements. Lancet 1998;352:233-4.

There are two case reports of creatine-related venous thrombosis in otherwise healthy adults. In the first case, an active 18-year-old male who had been taking an unspecified dose of creatine daily for 3 months was diagnosed with venous thrombosis via MRI. The patient reported increased thirst and fluid consumption when taking creatine. In the second case, an active 31-year-old male who had recently taken a 5-hour flight was diagnosed with deep vein thrombosis. He had been taking an unspecified dose of creatine. After stopping creatine and receiving anticoagulation therapy for 6 months, both patients' thromboses were resolved and did not recur. Researchers speculate that dehydration might be to blame for these adverse events, as dehydration increases the risk of thrombosis. In both cases, thrombophilic conditions were ruled out, and a temporal relationship between creatine consumption and thrombosis was established. However, it remains unclear if creatine was responsible for these thrombotic events.

1. Tan CW, Hae Tha M, Joo Ng H. Creatine supplementation and venous thrombotic events. Am J Med 2014;127(8):e7-8.

Isolated cases of renal dysfunction in patients taking creatine have been reported, including a case of interstitial nephritis in a healthy male and a case of renal insufficiency in a football player. In contrast to these cases, several clinical studies and case reports have shown that creatine does not affect markers of renal function in healthy adults. Doses studied included 5- to 7-day loading regimens of 12 to 21 grams daily, or maintenance doses of 3-10 grams daily for up to 2 years. In two additional studies, creatine supplementation 15.75 grams for 5 days followed by 4.25 grams daily for 20 days with carbohydrate and protein ingestion led to no change of renal stress markers. Other clinical research has shown that ingestion of creatine up to 30 grams daily for 5 years is not associated with an increased incidence of renal dysfunction.

Other case reports involve patients with pre-existing renal dysfunction. For example, in one case, a patient with a history of recurrent renal failure developed relapsing steroid-responsive nephritis syndrome after taking creatine. In another case, a patient with diabetic nephropathy who was taking creatine and metformin developed severe metabolic acidosis and acute renal failure. It is unclear if creatine contributed to this event, as metformin alone is known to cause metabolic acidosis. These case reports have raised concern that individuals with pre-existing renal dysfunction may be at increased risk for renal injury with creatine supplementation. However, no prospective clinical trials have been conducted in this population to clarify this concern.

In addition, two cases of acute kidney injury and hypercalcemia have been reported in 16 year old males that took 1-4 servings of creatine for less than 4 weeks; however, the creatine product contained unlabeled, very high doses of vitamin D, which is the likely cause of these symptoms.

In one survey, 13% of male collegiate athletes taking creatine reported dehydration. The Association of Professional Team Physicians has warned that creatine may cause dehydration, heat-related illnesses, and electrolyte imbalances, and reduce blood volume. Mild transient dehydration resulting in an elevated serum creatinine was also reported in a single person in a clinical trial. However, a study found that creatine supplementation during preseason football training had no effect on fluid or electrolyte status. Additionally, most high quality clinical research shows that creatine does not increase dehydration. A theoretical increase in risk of dehydration due to intracellular fluid shifts has led most creatine manufacturers to caution about adequate hydration with creatine supplementation.

1. Koshy KM, Griswold E, Schneeberger EE. Interstitial nephritis in a patient taking creatine. N Engl J Med 1999;340:814-5.
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3. Poortmans JR, Auquier H, Renaut V, et al. Effect of short-term creatine supplementation on renal responses in men (abstract). Eur J Appl Physiol Occup Physiol 1997;76:566-7.
4. Poortmans JR, Francaux M. Long-term oral creatine supplementation does not impair renal function in healthy athletes. Med Sci Sports Exerc 1999;31:1108-10.
5. Earnest CP, Almada AL, Mitchell TL. High-performance capillary electrophoresis-pure creatine monohydrate reduces blood lipids in men and women. Clin Sci (Colch) 1996;91:113-8.
6. Gualano B, Ugrinowitsch C, Novaes RB, et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol 2008;103:33-40.
7. Gualano, B., Ferreira, D. C., Sapienza, M. T., Seguro, A. C., and Lancha, A. H., Jr. Effect of short-term high-dose creatine supplementation on measured GFR in a young man with a single kidney. Am.J.Kidney Dis. 2010;55(3):e7-e9.
8. Gualano, B., de, Salles Painelli, V, Roschel, H., Lugaresi, R., Dorea, E., Artioli, G. G., Lima, F. R., da Silva, M. E., Cunha, M. R., Seguro, A. C., Shimizu, M. H., Otaduy, M. C., Sapienza, M. T., da Costa, Leite C., Bonfa, E., and Lancha Junior, A. H.
9. Neves, M., Jr., Gualano, B., Roschel, H., Lima, F. R., Lucia, de Sa-Pinto, Seguro, A. C., Shimizu, M. H., Sapienza, M. T., Fuller, R., Lancha, A. H., Jr., and Bonfa, E. Effect of creatine supplementation on measured glomerular filtration rate in postmeno
10. Lugaresi, R., Leme, M., de, Salles Painelli, V, Murai, I. H., Roschel, H., Sapienza, M. T., Lancha Junior, A. H., and Gualano, B. Does long-term creatine supplementation impair kidney function in resistance-trained individuals consuming a high-protein di
11. Poortmans, J. R. and Francaux, M. Renal dysfunction accompanying oral creatine supplements. Lancet 7-18-1998;352(9123):234.
12. Galvan E, Walker Dk, Simbo SY, et al. Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance. J Int Soc Sports Nutr. 2016 Mar 31;13:12.
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There have been reports of heat intolerance with oral creatine supplementation. Increases in formaldehyde production have been reported with creatine use. A-24 year-old man taking supratherapeutic doses of creatine monophosphate in combination with an energy supplement developed malignant hyperthermia after undergoing anesthesia. His symptoms included tachycardia, hypertension, hypercarbia, and hyperthermia. Environmental factors are suspected to have played a role in the development of malignant hyperthermia, so whether this adverse event was due to creatine at all is unclear.

In 1997, three collegiate wrestlers died after engaging in a rapid weight-loss program in order to qualify for competition. Initially creatine supplementation was considered to have contributed to or caused these deaths; however, investigations by the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA) did not confirm this belief. It appears that only one of the three wrestlers had been using creatine. Instead, the deaths were related to drastic, short-term weight loss in which the wrestlers wore rubber suits, avoided hydration, and performed workouts in rooms with temperatures up to 33 °C.

1. Juhn, M. S., O'Kane, J. W., and Vinci, D. M. Oral creatine supplementation in male collegiate athletes: a survey of dosing habits and side effects. J Am.Diet.Assoc 1999;99(5):593-595.
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Creatine-associated increase in body mass is well documented in randomized, controlled clinical trials and is often as large as 1-2 kg during the five-day loading period of creatine. This may be considered an unwanted adverse reaction in some individuals and a desired effect of supplementation in others. This weight gain may interfere with mass-dependent activities such as running and swimming. Muscle cramping due to creatine supplementation has been reported in controlled clinical trials and may result from water retention in skeletal muscle. However, most high quality clinical research shows that creatine does not increase the incidence of musculoskeletal injuries or muscle cramping. In one case report, rhabdomyolysis in a weight lifter using creatine 25 grams daily over a one-year period has been reported. Another case report describes an adult male who developed acute compartment syndrome of the leg after regular consumption of an unspecified amount of creatine and cocaine.

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In a small clinical trial of older, healthy males, one subject out of the 10 receiving creatine 5 grams four times daily for 10 days followed by 4 grams daily for 20 days reported a skin rash during the study. The type and severity of rash and whether it resolved after creatine was discontinued were not discussed. Also, skin rash has been reported by patients taking celecoxib and creatine; however, whether this effect was due to creatine or celecoxib is unclear.

Topically, burning, itching, redness, irritation, and perception of changes in skin temperature have been reported.

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