Creatine has not been shown in clinical studies to directly cause heart palpitations. No controlled trial has established a causal link between creatine monohydrate and cardiac arrhythmias. However, a small number of case reports exist, and there are plausible indirect mechanisms that could explain why some people notice palpitations after starting creatine, particularly during high-dose loading phases or when taking it as part of a multi-ingredient pre-workout supplement.
What the Evidence Actually Shows
The International Society of Sports Nutrition has stated that creatine supplementation is safe and provides long-term benefits at recommended doses. Large reviews of creatine research have not identified heart palpitations as a recognized side effect. The most commonly reported issues are gastrointestinal: upset stomach, diarrhea, and bloating, especially at higher doses.
That said, the evidence isn’t a clean bill of health for every scenario. A published case report described a 30-year-old man with no prior heart problems who showed up to an emergency department in atrial fibrillation (an irregular, rapid heart rhythm) while taking creatine monohydrate. His thyroid levels, magnesium, potassium, and drug screen were all normal, making creatine a “probable cause” in the authors’ assessment. Other anecdotal reports have also linked creatine to arrhythmia development. These are individual cases, not proof of a widespread effect, but they suggest the possibility isn’t zero.
How Creatine Could Indirectly Affect Heart Rhythm
Creatine is osmotically active, meaning it pulls water into your muscle cells. It enters muscles through a sodium-dependent transporter, and water follows to keep the cell’s fluid balance stable. Under normal conditions, your body’s sodium-potassium pumps compensate, so intracellular sodium levels don’t shift dramatically.
The problem arises during heavy sweating, intense exercise in heat, or inadequate fluid intake. When creatine locks more water inside muscle cells, less fluid is available in the rest of your body. This can theoretically lead to mild extracellular dehydration and electrolyte imbalance. Both of those are well-known triggers for heart palpitations. Magnesium and potassium, in particular, are critical for maintaining a steady heart rhythm, and even subtle drops can make your heart feel like it’s skipping or racing.
So while creatine itself may not directly irritate heart tissue, it can set up conditions where palpitations become more likely if you’re not staying well hydrated or replacing electrolytes lost through sweat.
The Loading Phase Raises the Risk
A creatine loading phase involves taking 20 to 25 grams per day for five to seven days, compared to a standard maintenance dose of 3 to 5 grams per day. According to the Cleveland Clinic, higher amounts of creatine can cause dizziness, elevated blood pressure, and muscle cramps, all of which overlap with or accompany the sensation of palpitations.
If you’ve recently started a loading phase and are noticing your heart fluttering or pounding, the dose is the first thing to consider. Skipping the loading phase entirely and starting with 3 to 5 grams daily will get your muscles fully saturated within three to four weeks instead of one. It just takes longer. This slower approach also significantly reduces the likelihood of side effects.
Pre-Workouts Are a More Likely Culprit
Many people take creatine as an ingredient in a multi-ingredient pre-workout supplement rather than on its own. This distinction matters enormously. Pre-workouts commonly contain high doses of caffeine, nitric oxide boosters, beta-alanine, and sometimes natural stimulants like bitter orange. These ingredients have a much stronger association with cardiac symptoms than creatine does.
One published case described a young woman who arrived at an emergency department with chest pain, palpitations, vomiting, and elevated markers of heart stress after taking a pre-workout with high caffeine and nitric oxide content. Caffeine is a cardiovascular stimulant that directly increases heart rate and can trigger palpitations even in healthy people. Nitric oxide agents and natural stimulants have been linked to cardiac events including, in rare cases, death.
If you’re experiencing palpitations and taking a pre-workout blend, the caffeine and stimulant ingredients are far more likely responsible than the creatine. Switching to plain creatine monohydrate, taken separately, is one way to test this.
Who Should Be More Cautious
People with a personal or family history of atrial fibrillation or other heart rhythm disorders should approach creatine with extra care. The case report authors specifically noted that athletes and individuals at risk for atrial fibrillation should be cautious about supplement use, since the cardiovascular effects remain uncertain in those populations.
The Mayo Clinic notes that creatine has been studied for conditions including congestive heart failure, but there isn’t enough evidence to recommend it as a treatment. For people with existing heart conditions, creatine hasn’t been proven harmful, but it also hasn’t been proven safe in that specific context. If you have a known cardiac condition and want to use creatine, that’s a conversation worth having with a cardiologist.
Reducing the Risk of Palpitations
If you want to take creatine and minimize any chance of heart-related side effects, a few practical steps help. First, skip the loading phase. The standard 3 to 5 grams per day is effective and far less likely to cause any side effects. Second, increase your water intake. Because creatine draws water into muscle cells, your body needs more total fluid to maintain normal hydration. This is especially important if you exercise in hot environments or sweat heavily.
Third, pay attention to electrolytes. Magnesium and potassium are the two minerals most closely tied to heart rhythm stability. If you’re sweating a lot and only drinking plain water, you may be diluting these minerals without replacing them. Foods rich in potassium (bananas, potatoes, leafy greens) and magnesium (nuts, seeds, whole grains) help, as do electrolyte drinks that aren’t loaded with sugar.
Finally, take creatine on its own rather than as part of a stimulant-heavy pre-workout blend. This lets you isolate whether creatine is actually the issue. Many people who blame creatine for palpitations are really reacting to 300 milligrams of caffeine and a cocktail of other stimulants consumed on an empty stomach before training.
When Palpitations Need Attention
Palpitations that are infrequent and last only a few seconds are common and usually harmless. They happen to most people at some point, supplement use or not. But palpitations that come with chest pain, fainting, severe dizziness, or significant shortness of breath are a different situation entirely and warrant emergency medical evaluation. The same is true for palpitations that are becoming more frequent over time or that last longer than a few seconds at a stretch, particularly if you have any history of heart disease.
If you stop taking creatine (or your pre-workout) and the palpitations resolve within a few days, that’s a strong signal the supplement was involved. If they persist after stopping, the cause lies elsewhere.