There’s no shortage of fitness and dietary supplements on the market, many of which are spiked with drug ingredients not advertised on their labels, misleading claims, and other risks. Roughly three in four Americans now use some form of supplementation on a regular basis, from multivitamins and probiotics to botanicals and protein powders.

But out of the thousands of products now on the market, creatine monohydrate is arguably the most legitimate supplement. It is widely used by athletes and bodybuilders to enhance strength, improve performance, and gain muscle mass.

According to a 2007 statement by the International Society of Sports Nutrition, experts consider creatine to be the most effective nutritional supplement for boosting athletic performance in terms of increasing high-intensity exercise capacity and lead body mass.

Creatine is one of the most widely studied supplements in sports medicine, with hundreds of studies thus far showing that its short- and long-term use is safe with no detrimental effects in otherwise healthy individuals.

What is creatine anyway?

Creatine is an amino acid found in the body’s muscles, as well as the brain, that helps to supply energy. Creatine is naturally found in red meat (i.e. beef and pork) and fish, although the levels obtained from these sources are generally far below those found in synthetic creatine supplements. The liver, pancreas, and kidneys also naturally produce creatine from protein in food, at a rate of about one gram per day.

More than 95% of the creatine found in your body is stored in muscles in the form of phosphocreatine, while the rest is found in the brain, kidneys, and liver.

When required, phosphocreatine is broken down to help the body produce more adenosine triphosphate (ATP), the primary carrier of energy in cells. The more ATP is readily available, the better equipped the body is to withstand intense exercise.

What are the effects of creatine on the body?

Creatine helps fuel our muscles, which is why people use it as a supplement to boost their athletic performance in the gym. Since creatine helps you clock in more reps and lift more, it promotes more muscle fiber tears, which the body can then repair and rebuild bigger and stronger as long the rest of your nutrition is on point. In other words, creatine makes you stronger, which means more muscle mass over time.

Besides more workload, the increased levels of phosphocreatine stored in your muscles can improve cell signaling, which aids muscle repair and growth. There is also evidence that creatine boosts muscle growth by reducing muscle breakdown and reducing myostatin levels.

A 2003 review of the scientific literature involving more than 500 studies on creatine found that short-term creatine supplementation improves maximal power/strength by 5% to 15%, work performed during sets of maximal effort muscle contractions by 5% to 15%, single-effort sprint performance by 1%-5%, and work performed during repetitive sprint performance by 5%-15%.

“Moreover, creatine supplementation during training has been reported to promote significantly greater gains in strength, fat-free mass, and performance primarily of high-intensity exercise tasks. Although not all studies report significant results, the preponderance of scientific evidence indicates that creatine supplementation appears to be a generally effective nutritional ergogenic aid for a variety of exercise tasks in a number of athletic and clinical populations,” the authors of the review added.

While loading up on creatine, people will also experience some weight gain — but not fat. Most people will gain between two and four pounds due to water retention in their first four weeks, making your muscles look bigger and fuller. Creatine contains zero calories so it can’t have any impact on your fat metabolism.

Aside from athletic performance, studies have linked creatine intake with improvements in age-related decline in skeletal muscle and bone mineral density, performance in cognitive tasks, and skin aging (when using a cream containing creatine) in terms of reducing skin sag and wrinkles in men.

Is creatine good for gaining muscle mass?

Many bodybuilders supplement with creatine monohydrate. A 2018 study that assessed the effect of a 4-week creatine supplementation in subjects who followed a complex training program three days per week concluded “that creatine supplementation combined with complex training improved maximal muscular strength and reduced muscle damage during training.”

Creatine supplements do not lead to an increase in muscle mass on their own — they’re not anabolic steroids. Instead, the phosphocreatine stored in the muscles releases extra ATP during high-intensity exercise, which allows athletes to perform more work, ultimately leading to more muscle mass when torn fibers repair. In some instances, creatine supplementation can lead to up to three times as much change in muscle fiber size as working out without supplementation.

Creatine also has other benefits for the body’s muscles. It may increase levels of IGF-1, considered a key hormone for muscle growth.

Is creatine safe?

Creatine has an outstanding safety profile. Although there have been anecdotal claims that creatine can cause dehydration, cramping, liver and kidney damage, and gastrointestinal distress, studies have shown that athletes who take creatine monohydrate have no greater, and a possibly lower, risk of these side effects than those who do not use the supplement.

Widespread use of creatine started in the 1990s, and so far no long-term side effects have been observed in athletes or the general population.

In certain situations, such as in patients with creatine synthesis deficiency, muscular dystrophy, diabetes, or those suffering orthopedic injury, creatine supplementation has medical uses.

In conjunction with short- and long-term studies in healthy populations, the evidence suggests that creatine supplementation appears to be safe when taken within recommended usage guidelines.

Creatine supplementation is not currently banned by any athletic organization. The International Olympic Committee has ruled that there was no need to ban creatine supplements since creatine is readily found in meat and fish and there is no valid test to determine whether athletes are taking it.

“It is the position of the International Society of Sports Nutrition that the use of creatine as a nutritional supplement within established guidelines is safe, effective, and ethical. Despite lingering myths concerning creatine supplementation in conjunction with exercise, CM remains one of the most extensively studied, as well as effective, nutritional aids available to athletes. Hundreds of studies have shown the effectiveness of CM supplementation in improving anaerobic capacity, strength, and lean body mass in conjunction with training. In addition, CM has repeatedly been reported to be safe, as well as possibly beneficial in preventing injury. Finally, the future of creatine research looks bright in regard to the areas of transport mechanisms, improved muscle retention, as well as treatment of numerous clinical maladies via supplementation,” said the International Society of Sports Nutrition in a joint statement.

What form of creatine should you take?

Not all creatine supplements are the same. The most widely studied and endorsed supplement is creatine monohydrate, which is available in powder, liquid, and pill form.

However, the powdered form may be the most effective. Previous studies have shown that liquid creatine and creatine ethyl ester can break down in the blood system.

Some companies add other ingredients besides creatine, such as electrolytes, fruit juice, and other substances. There is little evidence these extra ingredients help, and most research that found evidence of improved athletic performance from creatine intake did so for the 100% pure creatine powder form. As such, this is the most advisable form of creatine.

How much creatine should you take?

It takes a while before creatine stores in the muscles reach optimal levels for enhanced performance. According to a review by the International Society of Sports Nutrition, the fastest way to increase muscle creatine is to consume approximately 0.3 grams of creatine monohydrate per kg per day. Per these guidelines, an average adult weighing 70kg would have to load up on 20 grams of creatine for three days. Afterwards, elevated stores can be maintained with 3 to 5 grams of creatine per day.

Even less creatine supplementation can have a dramatic effect on your muscle stores. A 1996 study found that a 6-day creatine load at 20 grams per day increases muscle total creatine concentration by 20%. This elevated concentration was maintained when supplementation was continued at a rate of 2 g/day for a further 30 days. 

The bottom line: creatine monohydrate is the most studied supplement meant for enhancing athletic performance. Evidence suggests creatine supplementation improves strength, endurance, and muscle mass growth. It is safe to consume by healthy individuals, but as with any other supplement, it is best to opt for moderation.