Creatine is generally considered one of the safest sports supplements for health. However, the harmful effects of creatine and its side effects are indeed noted by scientists and doctors. Among them, there are many questionable and anecdotal claims, but there are also those that are associated with serious health risks… but not due to the harm of creatine itself. Read on.
Main thoughts:
Creatine is generally a safe supplement, provided it is used according to recommendations
Creatine: Harm and Side Effects of Use
1 The most important and reliable side effect of creatine use
Despite the many myths surrounding this, sometimes anecdotal, the only side effect of creatine that has been reliably confirmed multiple times is weight gain, due to an increase in muscle mass (1, 2, 3, 7, 8). Scientists confirm an increase of 0.9 to 1.7 kg.
This side effect is desirable for some sports (bodybuilding, American football players). For others, it can be negative (wrestlers, weightlifters), who may fall out of their weight category due to weight changes resulting from creatine use.
What is the reason for the weight gain as a result of creatine use?
There are two hypotheses:
- creatine promotes water retention in muscles;
- muscle mass is directly increasing.
Scientists still cannot provide a definitive answer. Some data suggests that both options may work.
One study showed that the use of creatine leads to a decrease in the volume of fluid excreted in urine during the first days of use. This clearly indicates that a greater amount, compared to normal, remains inside the body (4).
The fact of water accumulation in the body is confirmed by many reviews from athletes about creatine.
In another study (5), it was demonstrated that creatine intake leads to an increase in the synthesis rate of actin and myosin (the most important muscle proteins responsible for contraction) by about two times on the third day. This suggests that the increase in body mass when taking creatine may be explained by a direct increase in muscle mass.
The only reliable side effect of creatine use is weight gain: either due to water retention or direct muscle mass increase. The true reason remains unclear to scientists.
2 Creatine and Kidneys
Some are concerned about the question “Is creatine harmful to the kidneys?”.
Since creatine is a natural substance for our body, there should be no problems for the kidneys associated with its use.
There are grounds for concern about the harm of creatine to the kidneys with prolonged use in high doses (more than 20 grams per day), as creatine contains nitrogen, and the function of the kidneys is its disposal. However, scientists do not have sufficient data for definitive conclusions. If the doses are small (0.03 g/kg of body weight is considered normal), there is no reason for concern.
Experiment: Long-term studies on the harm of creatine to the kidneys were conducted on a group of young professional athletes (average age 24 years) who trained regularly for 5-10 years. For a period ranging from 10 months to 5 years, the athletes regularly took creatine and were monitored by scientists. The dose of creatine was individualized and ranged from 1 to 20 g, 1-4 times a day, i.e., from 1 to 80 grams of creatine among different athletes. Result: researchers found no impairment of kidney function in any of the athletes. Some of them occasionally reported headaches or muscle cramps, but there is no reason to believe that creatine was the cause 10.
Important: Creatine can indeed be dangerous for people with kidney diseases.
3 Harm of Creatine to the Heart
Long-term use of creatine in large doses can lead to some heart problems.
One possible side effect is heart arrhythmia. In one study, a generally healthy 30-year-old man taking creatine experienced atrial fibrillation. However, a single case is too little for definitive claims. Other factors, unknown or unaccounted for by the researchers, could have caused the arrhythmia.
A heart arrhythmia is noted by one amateur athlete in his review of creatine. He clearly states that he has always had heart problems and that they may have worsened after starting creatine supplementation.
When using creatine along with ephedrine and caffeine, the risk of ischemic stroke may increase; however, this assumption is also based on only one recorded case of an athlete who took this combination.
4 Other side effects of creatine use
Other side effects from creatine supplementation that athletes sometimes report include: diarrhea, gas, stomach heaviness, stomach cramps, spasms, increased urination, headaches, and decreased appetite. As can be seen, this is a full spectrum of various ailments. Most of them occur during the “loading” phase of creatine and disappear as soon as it ends. Unfortunately, there are no ways to determine whether these side effects are directly related to creatine consumption or caused by other dietary or lifestyle mistakes, as no long-term studies of this kind have been conducted.
Important: Most of the side effects listed above are observed when consuming large doses of creatine (6).
5 Harm of creatine: facts about the presence of banned substances
Important: For a complete picture, it should be noted that facts of serious harm from creatine to health have indeed been recorded by scientists and doctors. They were related to the fact that dietary supplements, including creatine, are considered food products rather than pharmaceuticals in the USA. This means that their manufacturers are not required to meet the same standards as drug manufacturers. According to WADA (World Anti-Doping Agency), there are known cases of intentional use of banned ingredients in creatine supplements to enhance effects.
Creatine is generally a safe supplement, provided it is used according to recommendations.
