Popular among bodybuilders, creatine supplementation is gaining traction for its potential use beyond athletic performance. Researchers are exploring its clinical role in managing muscular and neurologic disorders, as well as its application in geriatric care. But what evidence supports these broader uses? When is creatine appropriate to recommend, at what doses, and are there contraindications? Medscape\u2019s Portuguese edition spoke with several experts to examine how creatine supplementation may benefit patients in clinical practice.<\/p>\n
Like endogenous creatine, supplemental creatine is converted into phosphocreatine and stored in skeletal muscle, where it plays a critical role in rapid adenosine triphosphate (ATP) replenishment. \u201cSupplementation helps accelerate muscle recovery by providing an available energy reserve,\u201d explained Beatriz Leite, clinical nutritionist with a PhD in health sciences from the Federal University of S\u00e3o Paulo and a member of the Multiprofessional Committee of the Brazilian Society of Rheumatology, S\u00e3o Paulo, Brazil.<\/p>\n
The body naturally synthesizes around 1-2 g of creatine daily, and the compound is also present in animal-derived foods. About 1 kg of red meat contains roughly 5 g of creatine \u2014 so a 200-g serving provides about 1 g. The typical supplementation dose, ranging from 3 to 5 g\/d, is designed to complement both endogenous production and dietary intake to support intramuscular creatine accumulation.<\/p>\n
Safety Profile<\/p>\n
A recent meta-analysis<\/a> of 685 clinical trials concluded that creatine supplementation is not linked to clinically significant adverse effects and is generally well tolerated \u2014 particularly at recommended doses of 3-5 g\/d or 0.1 g\/kg\/d. \u201cCreatine monohydrate is essentially identical to what the body produces. It\u2019s metabolized the same way, and I see no meaningful risk of side effects. It\u2019s a very safe supplement,\u201d said Andr\u00e9a Fioretti, head of the Department of Sports and Exercise Endocrinology at the Brazilian Society of Endocrinology and Metabolism.<\/p>\n Concerns have lingered about creatine\u2019s potential to elevate serum creatinine levels and place strain on liver or kidney function. However, a meta-analysis<\/a> indicates that creatine does not significantly alter serum creatinine. \u201cCreatine is excreted by the kidneys as creatinine. So when a patient supplements with creatine, the apparent rise in serum creatinine is usually a false signal \u2014 not an indicator of renal damage,\u201d Fioretti explained.<\/p>\n Supporting this, a study<\/a> from the University of S\u00e3o Paulo found that creatine supplementation actually reduced levels of cystatin C, further reinforcing the absence of renal harm.<\/p>\n Nonetheless, Leite advised individualized assessment. \u201cIn patients with renal or hepatic conditions, more careful evaluation is essential. Supplementation should only be considered if there\u2019s a clear therapeutic benefit,\u201d she noted.<\/p>\n Gustavo Starling Torres, MD, sports medicine physician and director at the Brazilian Society of Exercise and Sports Medicine, agreed: \u201cThe supplementation protocol should always be individualized, taking into account therapeutic goals, patient tolerance, and overall clinical condition.\u201d<\/p>\n In such cases, renal function testing may be advisable. \u201cIf there\u2019s concern about kidney function, a creatinine test can help guide decisions,\u201d said Fioretti. \u201cThis ensures the supplement is used in patients who genuinely need it \u2014 those with muscle mass deficiencies.\u201d<\/p>\n Michele Trindade, PhD, adjunct professor in the Department of Physical Education at the State University of Maring\u00e1 in Maring\u00e1, Brazil, and vice president of the Brazilian Association of Sports Nutrition, also advised caution when considering creatine supplementation in pregnant or breastfeeding women and in children. \u201cThey\u2019re not currently included in official recommendations because there\u2019s insufficient safety and efficacy data for pregnant individuals and fetuses. We also don\u2019t yet know how much transfers into breast milk,\u201d she explained.<\/p>\n Regarding children, Trindade added that creatine is not recommended \u2014 even in cases of malnutrition. \u201cWhen treating a malnourished child, the priority is nutritional rehabilitation. Malnutrition involves more than loss of muscle mass; it includes deficiencies in total caloric intake and essential micronutrients like vitamins and minerals that regulate metabolic function.\u201d<\/p>\n Uncertain Benefits in Neurologic and Muscle Disorders<\/p>\n Like skeletal muscle, the brain depends on the rapid ATP regeneration provided by the creatine-phosphocreatine system, raising interest in its possible neurologic benefits. A systematic review<\/a> in healthy older adults suggested that \u201coral creatine administration may improve short-term memory and intelligence\/reasoning of healthy individuals, but its effect on other cognitive domains remains unclear, leaving questions around ideal dosing and the mechanisms<\/a> underlying potential cognitive enhancement.\u201d<\/p>\n Another review<\/a> exploring creatine\u2019s potential in neurologic conditions noted that while early human studies \u2014 particularly in neurodegenerative diseases \u2014 are promising, more robust evidence is needed. Well-designed, long-term randomized controlled trials are essential to establish efficacy, cost-effectiveness, and safety in these populations.<\/p>\n Creatine has also been studied as an adjunctive therapy for conditions such as Duchenne muscular dystrophy, amyotrophic lateral sclerosis (ALS), and certain metabolic myopathies. However, the available data remain inconclusive. In the context of muscle disorders, a systematic review<\/a> observed that creatine monohydrate may help reduce intracellular calcium accumulation and provide energy for muscle contraction, though the optimal dosing and magnitude of effect are still unclear.<\/p>\n In a study<\/a> involving 107 patients with probable or confirmed ALS, daily creatine monohydrate was well tolerated and associated with a trend toward increased survival \u2014 mirroring findings from an earlier trial. However, the authors concluded that supplementation at 5 g\/d did not significantly improve markers of disease progression or reduce fatigue during isometric contraction, despite anecdotal reports from participants.<\/p>\n Geriatric Use<\/p>\n Findings on creatine supplementation in older adults remain mixed. \u201cEvidence is very limited in this population. Few studies have demonstrated improvements in physical performance or muscle strength,\u201d said Ivan Aprahamian, MD, PhD, internal medicine and geriatrics specialist and a member of the Brazilian Society of Geriatrics and Gerontology.<\/p>\n Aprahamian noted that creatine may serve as a helpful adjunct in managing sarcopenia. \u201cIn older adults with reduced muscle mass or strength who are engaged in resistance training, creatine may support improvements in muscle health,\u201d he explained. The recommended dosage remains 3-5 g\/d, taken consistently.<\/p>\n In such cases, Fioretti recommended first screening for sarcopenia using the SARC-F questionnaire \u2014 which assesses autonomy and independence \u2014 alongside grip strength testing. \u201cIf reduced strength is confirmed, further evaluation of muscle mass using bioimpedance or DEXA, followed by a physical performance assessment, is warranted,\u201d she said.<\/p>\n On the basis of results, a resistance training program can be initiated in combination with creatine supplementation and appropriate carbohydrate and protein intake. \u201cOlder adults often consume excessive carbohydrates and insufficient protein. After approximately 6 months, it\u2019s advisable to repeat assessments to monitor improvements in muscle mass and physical function,\u201d Fioretti added.<\/p>\n Leite agreed: \u201cCreatine is not a miracle solution. It must be combined with a well-structured dietary plan.\u201d Even in sedentary seniors, she noted, supplementation may still offer benefits. \u201cWhile it may not significantly increase muscle mass, it can help reduce the rate of muscle loss,\u201d she explained.<\/p>\n For physically inactive older adults, the standard dose of 3-5 g\/d is still recommended. \u201cThis may support musculoskeletal health, though the effect on strength is modest,\u201d said Trindade, who also cautioned that responses may vary by sex. Limited data<\/a> suggest that women \u2014 who typically have higher baseline intramuscular creatine levels \u2014 may be less responsive to supplementation. \u201cWe don\u2019t fully understand why, but it\u2019s likely related to hormonal differences.\u201d<\/p>\n Established Benefits<\/p>\n Despite a growing number of hypotheses, robust evidence currently supports creatine supplementation primarily in the context of sports medicine. Misconceptions persist \u2014 particularly the belief that creatine directly causes muscle hypertrophy. \u201cIn high-intensity, short-duration resistance training, where energy reserves are quickly depleted, creatine helps by rapidly replenishing ATP. This indirectly supports muscle hypertrophy,\u201d explained Leite.<\/p>\n In athletic settings, creatine can be taken either before or after exercise, with comparable benefits. \u201cScientific literature shows that timing matters less than consistency. Regular use is key to saturating muscle creatine stores,\u201d said Torres.<\/p>\n Creatine\u2019s effect is cumulative. \u201cWhat matters is the total amount stored in muscle,\u201d noted Trindade. \u201cAfter ingesting monohydrate, blood levels peak at around an hour, and the creatine is distributed to muscles that haven\u2019t yet reached storage capacity. Once saturated, muscles rely on these reserves.\u201d<\/p>\n For fitness professionals, the benefits are often seen in practice. \u201cAmong clients who take creatine after workouts, I\u2019ve observed better lean mass gains \u2014 which is often their primary goal,\u201d said Celina Moreno, a trainer since the 1970s who witnessed the early rise of powdered supplements in gyms.<\/p>\n Alexandre Pereira da Costa Filho, who works at a chain of fitness centers, takes 9 g of creatine before bed \u2014 about 0.1 g\/kg\/d for his 86 kg body weight. He cautioned that loading protocols involving high initial doses followed by lower maintenance levels should be guided by a professional. \u201cOnly do this under the supervision of a nutritionist. Always consult a qualified professional before making decisions,\u201d he advised.<\/p>\n For those seeking faster performance gains, Trindade recommended a loading phase: 20 g\/d, divided into four doses, for 5 days, followed by a maintenance dose of 3-5 g\/d.<\/p>\n However, this protocol may cause fluid retention and modest weight gain. \u201cMost people don\u2019t notice it, but it depends on whether they\u2019re exercising enough to compensate,\u201d added Fioretti.<\/p>\n Quality Control<\/p>\n In April, Brazil\u2019s national health regulatory agency, Anvisa, published an analysis<\/a> of 41 creatine supplements from 29 manufacturers. Only one product had an incorrect concentration, but 40 showed labeling discrepancies. \u201cSome products may contain less creatine than declared \u2014 or even contaminants, especially when unregulated,\u201d warned Torres. He advised choosing certified products to minimize risk.<\/p>\n