Creatine, a naturally occurring compound in the body, has garnered significant attention for its role in energy production, muscle function, and potential therapeutic applications. This article aims to provide a comprehensive overview of creatine, its benefits, potential side effects, and how it can be integrated into one's diet.
What is Creatine?
Creatine is a natural source of energy that plays a crucial role in muscle contraction. It facilitates a steady supply of energy within the muscles, particularly during exercise. About half of the body's creatine supply, approximately 1 to 2 grams per day, comes from dietary sources, especially protein-rich foods like red meat (pork, veal, and beef), seafood (fish and shellfish), and animal milk (cow, goat, and sheep milk). The remaining half is produced naturally in the liver, kidneys, and pancreas, with about 95% being delivered to the skeletal muscles for use during physical activity. The rest goes to the heart, brain and other tissues.
Creatine supplements are also available in various forms, including powders, tablets, capsules, liquids, and energy bars. These supplements are often used by individuals who engage in intense workouts or have insufficient creatine intake through their diet.
Creatine (N-aminoiminomethyl-N-methyl glycine) is a naturally occurring and nitrogen-containing compound comprised from amino acids that is classified within the family of guanidine phosphagens. Creatine is synthesized endogenously from arginine and glycine by arginine glycine amidinotransferase (AGAT) to guanidinoacetate (GAA). The GAA is then methylated by the enzyme guanidinoacetate N-methyltransferase (GAMT) with S-adenosyl methionine (SAMe) to form creatine. The kidney, pancreas, liver, and some regions in the brain contain AGAT with most GAA formed in the kidney and converted by GMAT to creatine in the liver. Endogenous creatine synthesis provides about half of the daily need for creatine. The remaining amount of creatine needed to maintain normal tissue levels of creatine is obtained in the diet primarily from red meat and fish or dietary supplements. About 95% of creatine is stored in muscle with the remaining amount found in other tissues, like the heart, brain, and testes. Of this, about 2/3 of creatine is bound with inorganic phosphate (Pi) and stored as phosphocreatine (PCr) with the remainder stored as free creatine (Cr). The total creatine pool (Cr + PCr) is about 120 mmol/kg of dry muscle mass for a 70 kg individual who maintains a diet that includes red meat and fish. Vegetarians have been reported to have muscle creatine and PCr stores about 20-30% lower than non-vegetarians. The body breaks down about 1-2% of creatine in the muscle per day into creatinine which is excreted in the urine. Degradation of creatine to creatinine is greater in individuals with larger muscle mass and individuals with higher physical activity levels. Therefore, a normal-sized individual may need to consume 2-3 g/day of creatine to maintain normal creatine stores depending on diet, muscle mass, and physical activity levels. In fact, Wallimann and colleagues noted that since creatine stores are not fully saturated on vegan or normal omnivore diets that generally provide 0 or 0.75-1.5 g/day of creatine, daily dietary creatine needs may be in the order of 2-4 g/person/day to promote general health.
Benefits of Creatine Supplementation
Creatine supplementation is one of the most studied and effective ergogenic aids for athletes. The multifaceted mechanisms by which creatine exerts its beneficial effect include increasing anaerobic energy capacity, decreasing protein breakdown, leading to increased muscle mass and physical performance.
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Enhanced Athletic Performance
Many amateur and professional athletes take creatine supplements to aid their workout routines and improve their recovery. Creatine creates "quick burst" energy and increased strength, which improves your performance without affecting your ability to exercise for longer periods (aerobic endurance).
Creatine may enhance athletic performance. It contributes to rapid energy production and may enhance power or speed bursts requiring short periods of anaerobic activity. The reason could be related to the association of creatine supplementation and increased glycogen storage in muscle.
Creatine supplementation has been reported to increase muscle creatine and PCr levels, enhance acute exercise capacity, and improve training adaptations. The improvement in performance has generally been 10-20% on various high-intensity exercise tasks that include lifetime fitness activities like fitness/weight training, golf, volleyball, soccer, softball, ice hockey, running, and swimming, among others. Ergogenic benefits have been reported in men and women from children to elderly populations, although the majority of studies have been conducted on men.
The International Society of Sports Nutrition (ISSN) concluded that creatine is "the most effective ergogenic nutritional supplement currently available to athletes in terms of increasing high-intensity exercise capacity and lean body mass during training".
Muscle Growth and Strength
Studies show that regularly taking creatine, weightlifting, and exercising can help increase muscle growth in people 18 to 30 years old. Creatine supplementation does not build muscle. However, creatine supplementation along with regular resistance training and a well-balanced diet may offset age-related sarcopenia.
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Creatine may enhance athletic performance. It contributes to rapid energy production and may enhance power or speed bursts requiring short periods of anaerobic activity. The reason could be related to the association of creatine supplementation and increased glycogen storage in muscle. There is also some evidence that creatine supplementation along with adequate calorie and protein intake can hasten muscle recovery after strenuous exercise. Creatine supplementation does not build muscle. However, creatine supplementation along with regular resistance training and a well-balanced diet may offset age-related sarcopenia.
Cognitive Function
Studies suggest that creatine supplements may help brain function in people 60 and older. This includes short-term memory, reasoning, and neuroprotection (keeping groups of nerve cells safe from injury or damage). Creatine supplementation may help manage the impacts of sleep deprivation. Creatine may reduce the negative effects of sleep deprivation. A 2024 study found that a single, high dose of creatine may help improve cognitive performance in people experiencing sleep deprivation. This study is very small, however.
Potential Therapeutic Applications
Researchers have been investigating the potential therapeutic role of creatine supplementation on health-related conditions such as diabetes, sarcopenia, osteoporosis, cancer, rehabilitation, cognition, and cardiovascular health, among others. Creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised.
Creatine supplementation has been reported to help lower cholesterol, triglycerides and/or manage blood lipid levels; reduce the accumulation of fat on the liver; decrease homocysteine thereby reducing risk of heart disease; serve as an antioxidant; enhance glycemic control; reduce the progress of some forms of cancer; increase strength and muscle mass; minimize bone loss in some studies; improve functional capacity in osteoarthritic and fibromyalgia patients; enhance cognitive function particularly in older populations; and, in some instances, improve the efficacy of some anti-depressant medications.
Benefits for Women
Men and women report benefits to using creatine. But some studies note that women may not gain as much strength or muscle mass as men. A 2021 review suggests creatine supplementation may have several benefits for females, such as improving: muscular strength, function, and performance during premenopause, mood and mental cognition, bone health.
Read also: Creatine and Vegetarian Diets
Creatine for Bodybuilding and Cutting Phases
Bodybuilders may use creatine to support certain phases of their training and preparation for competition. Creatine is one of the most common nonhormonal supplements bodybuilders use.
Cutting is a training phase bodybuilders may use before a competition to decrease body fat and increase muscle definition. During cutting, people reduce their calorie intake but maintain a high protein intake. Bodybuilders may use creatine during the cutting phase, as it may increase the physical results of resistance training.
Creatine may indirectly help with fat loss during cutting. According to a 2023 review, creatine may improve the capacity to exercise at high intensity. This may mean people can exercise for longer and increase the results of training, such as muscle growth, mass, and strength. Increased exercise intensity and duration may help promote fat loss and increase muscle mass.
Other research suggests creatine may aid weight loss. A 2023 analysis found that creatine supplementation with resistance training may reduce body fat in people ages 50 years or older.
Potential Side Effects and Safety Considerations
Studies show that it’s safe for many people to take creatine supplements.
General Safety
The majority of research suggests creatine supplementation is safe when taken at the recommended daily dose. Creatine might be unsafe for people with preexisting kidney problems. There is little evidence to suggest any risk of moderate creatine supplementation in people with typical kidney function. When used orally at appropriate doses, creatine is likely safe to take for up to five years.
Specific Concerns
Some people avoid creatine because they worry about certain myths, including kidney damage, liver damage, kidney stones, weight gain, bloating, dehydration, hair loss, muscle cramps, digestive concerns, and rhabdomyolysis. A 2021 review found that many studies don’t support these side effects.
Creatine can slightly raise creatinine levels in the blood. Creatinine is commonly measured to diagnose kidney or liver conditions. However, the fact that creatine raises creatinine levels does not mean it’s harming your liver or kidneys.
As with many supplements or medications, excessive doses of creatine may cause digestive issues. In a 2008 study, a 5-g dose taken twice daily caused diarrhea in 29% of participants, which was not significantly different from the placebo. However, a 10-g dose taken once daily increased diarrhea risk by 56%. For this reason, the recommended serving is set at 3 to 5 g daily. The 20-g loading protocol is also split into 4 servings of 5 g each over a day.
Precautions and Warnings
It is important to remember that, although creatine is a "natural" product, it is not always safe to take creatine supplements. The Food and Drug Administration does not regulate nutritional supplements. According to a study by the Mayo Clinic, many young athletes who take creatine supplements rely on the advice of friends, not doctors.
Because of these unknown risks, children and adolescents younger than 18 years and pregnant or nursing women should never take creatine supplements.
If you have bipolar disorder, creatine might make mania worse. If you have kidney disease, speak with a healthcare professional before using creatine. Caffeine and creatine taken together may make symptoms of Parkinson disease worse. If you have Parkinson disease and take creatine, use caffeine with caution.
As with any diet or supplement regimen, it’s best to speak with a healthcare professional before taking creatine. Creatine may interact with certain medications. You may also wish to speak with a doctor if: you take medications that affect your liver, kidneys, or blood sugar, you’re pregnant or nursing, you have a serious medical condition, such as heart disease.
Dehydration and Muscle Cramps
Creatine causes muscles to retain more water. People who take creatine supplements may gain weight because of water retention in the body's muscles.
Creatine alters your body’s stored water content, driving additional water into your muscle cells. However, this shift in cellular water content is minor, and the ISSN found that no research supports these claims. Instead, the ISSN notes that many studies found creatine supplementation may have a hyper-hydrating effect that could help prevent dehydration and muscle cramps when exercising in hot temperatures. Similarly, a 3-year 2003 study of college athletes found that those taking creatine had fewer cases of dehydration, muscle cramps, or muscle injuries than those not taking it. They also missed fewer sessions due to illness or injury. Based on the current evidence, creatine does not cause dehydration or cramping. It may even protect against these conditions.
Weight Gain
People who take creatine supplements may gain weight because of water retention in the body's muscles.
This weight gain, however, is due to an increase in water weight, not fat. A 2019 study found that taking 2 grams (g) of creatine daily and exercising twice weekly for 5 weeks helped participants ages 50 years and older lose slightly more body fat than participants who only exercised. A 2023 review found similar results in people younger than 50 years old.
Over the long term, creatine users may continue to increase their body weight more than people who don’t take it. However, this weight gain is due to increased muscle mass, not body fat. Increased muscle mass may especially benefit older adults, individuals with obesity, and those with certain diseases.
Not Recommended for Everyone
There is a lack of long-term research into whether taking creatine is safe, especially in children and adolescents. People should also avoid taking creatine if they are pregnant or nursing. The long-term health effects of creatine supplementation are unknown, including its impact on organs or interactions with other supplements or medications. People with kidney problems should not take creatine.
Dosage and Forms of Creatine
Creatine is found in foods such as meat and seafood. Creatine is also found in many different types of sports supplements.
Dosage Recommendations
The general recommendation for people who do take a creatine supplement is 3 to 5 grams per day.
In supplements, creatine has most often been used by adults in a one-time loading dose of up to 20 grams by mouth daily for up to 7 days, followed by a maintenance dose of 2.25-10 grams daily for up to 16 weeks. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.
The most effective and rapid way to increase muscle creatine stores is to ingest 5 g of creatine monohydrate four times daily for 5-7 days (i.e., 0.3 g/kg/day). However, some studies have shown that consuming 2-3 g/day of creatine for 30 days can also effectively increase muscle creatine stores.
It is prudent for individuals to consume at least 3 g/day of creatine to support general health as one ages.
Common Forms
Creatine supplements come in a wide variety of brand names and products. The most common creatine supplement is creatine monohydrate. It’s a dietary supplement that increases muscle performance in short-duration, high-intensity resistance exercises, such as weightlifting, sprinting and bicycling.
There are different forms of creatine available, but creatine monohydrate may be the best option as it is the most widely studied and affordable type.
Dietary Sources of Creatine
About half of your body’s supply of creatine (1 to 2 grams/day, about the size of 1 to 2 jellybeans) comes from your diet, especially protein-rich foods such as: Red meat (pork, veal and beef), Seafood (fish and shellfish), Animal milk (like cow, goat and sheep milk).
Foods that tend to have richer amounts of creatine include meats, fish, and cow's milk.
Interactions
Combining caffeine with creatine might decrease the efficacy of creatine. Use of creatine with a daily amount of caffeine greater than 300 milligrams might also worsen the progression of Parkinson's disease.
Creatine may cause dehydration, so taking it with other dehydrating substances, such as alcohol, may not be safe.
Creatine and Appetite
There is no evidence to suggest that creatine reduces appetite. Some possible effects of creatine, though, may indirectly impact appetite, such as increased energy use or dehydration.