Creatine is naturally produced by your pancreas and is stored in your skeletal muscles and your brain for use as energy. Creatine has been manufactured commercially as a nutritional supplement designed to increase exercise performance, particularly resistance training exercise, in order to increase the size and strength of your muscles. Creatine supplementation has several notable side effects, including kidney stress, energy loss after supplementation, water retention, and mood changes, including depression and anxiety.
Kidney Stress
Creatine supplementation increases your muscles' ability to contract, which creates a variety of metabolites that enter your bloodstream. Metabolites, including lactic acid and other compounds, are by-products of the energy producing metabolic pathways in your skeletal muscles. Some metabolites are removed from your body through your urine, which can place extra stress on your kidneys. If you suffer from weak kidneys or have an underlying kidney condition, the extra stress placed on them resulting from creatine supplementation may cause further kidney damage, and in some cases, kidney failure.
Energy Loss
Creatine supplementation causes your body to retain elevated amounts of creatine phosphate, which aids in energy production, particularly during exercise. When you stop supplementing with creatine, your muscles will no longer contain as much creatine phosphate, which will leave you feeling weaker and more fatigued during exercise. Some users may experience weight loss after stopping creatine supplementation. The rapid energy loss experienced after stopping creatine supplementation may lead to chronic fatigue syndrome, which can decrease exercise performance.
Water Retention
Creatine causes water retention in your skeletal muscles, making you feel bloated. When creatine is stored in your muscles, several molecules of water are stored with it. This may make your muscles appear fuller and healthier, but can also lead to unexpected weight gain. Water retention causes your body to conduct more heat, which can increase your heart rate and blood pressure. After you stop creatine supplementation, you may experience a rapid loss of body water and body weight.
Creatine and Depression
Creatine supplementation may indirectly offset the balance of certain brain chemicals, called neurotransmitters, that can affect your mood and increase the symptoms of depression and anxiety. By pulling water into your muscles, creatine increases the risk for developing dehydration by making less water available to your other body tissues. When your body is dehydrated, neurotransmitters such as serotonin and dopamine, are suppressed. Water acts as a catalyst for serotonin and dopamine production in the brain. Lower levels of these two neurotransmitters can cause you to experience an increase in symptoms of depression, anxiety, mental fatigue, and sadness.
References
- "Journal of Hyperplasia Research"; Creatine: A Meta-analysis; J.D. King; 2005
- "Anabolic Primer"; Phil Embleton and Gerard Thorne; 1998
