Creatine supplementation does not raise heart rate in the vast majority of research. Across studies measuring resting heart rate, exercise heart rate, and post-exercise recovery, creatine either leaves heart rate unchanged or nudges it slightly lower. The fear that creatine speeds up your pulse likely comes from confusing it with stimulant-based supplements, but creatine itself has no stimulant properties. That said, the story gets more interesting when you look at specific conditions like exercising in the heat, and there is one notable case report of a heart rhythm disturbance that deserves honest discussion.
Resting Heart Rate Stays About the Same
If creatine were revving up the cardiovascular system, you would expect it to show up first in resting heart rate. It does not. A study of bodybuilders compared those using creatine supplements to non-supplementing bodybuilders and a sedentary control group. The creatine users had an average resting heart rate of about 70 beats per minute, which was statistically indistinguishable from the sedentary controls at roughly 72 beats per minute.1PubMed. Effects of creatine supplementation on cardiac autonomic functions in bodybuilders The non-supplementing bodybuilders actually had the lowest resting rate of the three groups, around 62 beats per minute, but that likely reflects the cardiovascular conditioning that comes with regular training rather than anything harmful about creatine. In rat models, creatine supplementation similarly produced no changes in baseline cardiac function.2PubMed. The effect of creatine supplementation on myocardial function, mitochondrial respiration and susceptibility to ischaemia/reperfusion injury in sedentary and exercised rats
A study looking at catecholamines and cortisol, the stress hormones that would drive a resting heart rate increase, found no significant differences between creatine and placebo groups even under the added stress of sleep deprivation.3PubMed. Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol If creatine were stimulating the sympathetic nervous system, you would see it reflected in those hormone levels. It simply is not there.
Heart Rate During Exercise
The picture during exercise is mixed but still leans in the direction of “no increase.” One study of endurance-trained men had participants exercise to exhaustion in the heat after a week-long creatine loading phase. Rather than climbing, heart rate was actually reduced in the creatine group compared to placebo.4International Journal of Sport Nutrition and Exercise Metabolism. The Effects of Creatine Supplementation on Cardiovascular, Metabolic, and Thermoregulatory Responses during Exercise in the Heat in Endurance-Trained Humans Another study found a significant decrease in maximum heart rate of about 4% after creatine supplementation.5Journal of Science and Medicine in Sport. Effects of creatine supplementation on aerobic power and cardiovascular structure and function
Not all exercise studies show that reduction, though. A trial measuring heart rate and oxygen uptake responses during exercise found that creatine did not change either metric.6PubMed Central. Role of creatine supplementation on exercise-induced cardiovascular function and oxidative stress And a study comparing creatine to thiamine supplementation found no meaningful difference in how quickly heart rate recovered after exercise.7Britain International of Exact Sciences (BIoEx) Journal. A Comparison of Creatine and Thiamine Supplementation on Heart Rate Recovery and Blood Lactate Levels So the evidence clusters around “no change” with occasional hints of a mild reduction, and essentially nothing pointing toward an increase.
Why Creatine Sometimes Lowers Heart Rate in the Heat
The studies showing a slight heart rate reduction tend to involve exercise in hot conditions, and the mechanism behind this is one of the more interesting angles. Creatine draws water into cells. During a typical loading phase of around 20 grams per day for a week, total body water increases, and this extra fluid acts as a buffer against dehydration. When your body has more fluid to work with, it can maintain blood volume more easily, which means the heart does not have to beat as fast to deliver the same amount of blood to working muscles and skin.
One study found that creatine loading increased total body water by about 0.6 liters, and when combined with glycerol-based hyperhydration the increase reached nearly 0.9 liters. Both the creatine-only and the combined regimens reduced heart rate, core temperature, and perceived effort during exercise.8International Journal of Sport Nutrition and Exercise Metabolism. Creatine and Glycerol Hyperhydration in Trained Subjects before Exercise in the Heat A systematic review with meta-analyses looked across the available controlled trials of athletes exercising in the heat and concluded that creatine at recommended doses did not cause any adverse thermoregulatory or fluid-balance effects.9PubMed Central. Does creatine supplementation hinder exercise heat tolerance or hydration status? A systematic review with meta-analyses
This matters because an older concern about creatine was that it caused dehydration and cramping, which could theoretically raise heart rate. The evidence runs in the opposite direction. By increasing intracellular water, creatine may improve thermoregulation during prolonged exercise in warm environments.4International Journal of Sport Nutrition and Exercise Metabolism. The Effects of Creatine Supplementation on Cardiovascular, Metabolic, and Thermoregulatory Responses during Exercise in the Heat in Endurance-Trained Humans That said, when researchers tested creatine under conditions of deliberate dehydration, the heart rate benefit disappeared, with both the creatine and placebo groups hitting about 192 beats per minute during exercise.10PubMed Central. Creatine use and exercise heat tolerance in dehydrated men Creatine is not a magic shield against cardiovascular strain if you let yourself get dehydrated anyway.
Blood Pressure and Vascular Stiffness
Heart rate is only one part of cardiovascular load, and some people who ask about heart rate are really wondering whether creatine stresses the heart or blood vessels more broadly. The blood pressure data is reassuring. A study of both men and women found that acute creatine loading increased fat-free mass but did not change blood pressure, plasma creatinine, or creatine kinase activity.11PubMed. Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women
A more recent randomized controlled trial in older men actually showed that creatine may improve arterial stiffness. The creatine group experienced a statistically significant improvement in a measure of vascular stiffness, and systolic blood pressure showed a trend toward dropping from roughly 144 mmHg to 136 mmHg, although that particular change did not quite reach statistical significance.12PubMed. Effects of acute creatine supplementation on cardiac and vascular responses in older men; a randomized controlled trial These findings are preliminary and from a single trial, so they should not be oversold. But they certainly do not point toward creatine being a cardiovascular stressor.
The Atrial Fibrillation Case Report
The one piece of evidence that occasionally gets flagged by people worried about heart rhythm is a published case report of a 30-year-old man who arrived at an emergency department with atrial fibrillation and a rapid heart rate. He had no meaningful medical history, normal thyroid function, normal electrolytes, no drug or alcohol use, and the only unusual finding was that he had been taking creatine monohydrate.13PubMed. Lone atrial fibrillation associated with creatine monohydrate supplementation
This case report deserves honest context. A single case report cannot establish causation. Atrial fibrillation in otherwise healthy young men, called “lone atrial fibrillation,” occurs in the general population without any supplement involvement. The authors themselves described this as an association, not a proven cause. Millions of people use creatine, and if it routinely triggered arrhythmias, clinical trials would have caught it by now. Still, if you have a personal or family history of atrial fibrillation or other rhythm disorders, it is reasonable to mention your creatine use to a cardiologist. That is not because the evidence says creatine causes arrhythmias, but because disclosing all supplements to your doctor is just good practice.
How Creatine Functions Inside the Heart
The heart is one of the most energy-hungry organs in your body, and creatine plays a genuine role in keeping it fueled. The heart relies on a shuttle system where phosphocreatine carries energy from the mitochondria, where it is produced, to the parts of the cell that need it for contraction. This phosphocreatine buffer ensures that ATP levels remain stable even when the heart is working hard.14PubMed. Respiratory control and the integration of heart high-energy phosphate metabolism by mitochondrial creatine kinase When demand spikes, the creatine kinase system can regenerate ATP almost instantly without waiting for the slower process of oxidizing fuel.
Beyond energy supply, phosphocreatine also interacts with cell membranes in ways that may be protective. Research has shown that it can stabilize cardiac cell membranes, reduce the production of harmful byproducts during low-oxygen conditions, and decrease the frequency of arrhythmias in experimental models of oxygen deprivation.15PubMed. Systems bioenergetics of creatine kinase networks: physiological roles of creatine and phosphocreatine in regulation of cardiac cell function The creatine kinase enzyme is also physically associated with ATP-sensitive potassium channels in heart cells, which are part of the electrical system that governs heart rhythm.16PubMed Central. Creatine kinase is physically associated with the cardiac ATP-sensitive K+ channel in vivo This is a normal part of cardiac physiology, not something creatine supplementation disrupts. A review paper concluded that supplementation increases creatine content even in the normal heart and is generally safe.17PubMed Central. Role of Creatine in the Heart: Health and Disease
Creatine in People With Heart Failure
If creatine caused cardiovascular problems, you would not expect researchers to give it to people who already have heart disease. But they have, and the results are cautiously encouraging. In a double-blind, placebo-controlled trial, patients with chronic heart failure who took 20 grams of creatine daily for ten days saw no change in ejection fraction, the measure of how well the heart pumps. What did improve was skeletal muscle strength and endurance, with one-legged exercise performance increasing by about 21% and two-legged performance by about 10%.18PubMed. Creatine supplementation in chronic heart failure increases skeletal muscle creatine phosphate and muscle performance For heart failure patients, whose daily lives are limited by muscle fatigue as much as by cardiac output, that kind of improvement matters.
A separate trial in heart failure patients found that creatine combined with physical training reduced markers of inflammation and endothelial dysfunction.19PubMed Central. Effects of Complementary Creatine Monohydrate and Physical Training on Inflammatory and Endothelial Dysfunction Markers Among Heart Failure Patients These are small studies, and creatine is not a treatment for heart failure. But the fact that it can be used safely in this population, without worsening cardiac function or producing heart rate abnormalities, speaks to its cardiovascular safety profile.
When Pre-Workouts Muddy the Picture
A lot of the anxiety about creatine and heart rate probably comes from the pre-workout supplement market. Many popular pre-workout powders contain creatine alongside caffeine, beta-alanine, and sometimes other stimulants. Caffeine absolutely raises heart rate at higher doses, and the tingling sensation from beta-alanine can feel alarming even though it is harmless. If you take one of these combination products and notice your heart pounding, the creatine is almost certainly not the ingredient responsible.
A randomized, double-blind, crossover trial specifically tested creatine nitrate and caffeine both individually and in combination. Heart rate and blood pressure remained consistent before and after exercise regardless of whether participants received creatine nitrate, caffeine, the combination, or placebo.20PubMed Central. The Effect of Creatine Nitrate and Caffeine Individually or Combined on Exercise Performance and Cognitive Function: A Randomized, Crossover, Double-Blind, Placebo-Controlled Trial Another acute safety study of a multi-ingredient pre-workout product containing creatine found no changes in ECG-corrected QT interval, which is a sensitive marker of heart rhythm disturbance.21PubMed Central. Effects of a pre-workout supplement on lean mass, muscular performance, subjective workout experience and biomarkers of safety
If you are experiencing a noticeably elevated heart rate and you take a pre-workout blend, try isolating the ingredients. Plain creatine monohydrate mixed in water or juice is the cleanest way to test whether it is actually the creatine. For most people, it will not be.
Do Men and Women Respond Differently
Creatine research has historically skewed heavily toward male participants, which leaves a gap in confidence about whether women experience different cardiovascular effects. One study that directly compared the sexes found that short-term creatine supplementation did not affect thermoregulation or cardiovascular responses differently between men and women exercising in a temperature-controlled environment.22PubMed Central. A Comparison of Thermoregulation With Creatine Supplementation Between the Sexes in a Thermoneutral Environment Both sexes showed the expected increase in heart rate over the course of exercise, but creatine did not alter that pattern for either group. The acute creatine loading study mentioned earlier that found no blood pressure changes also included both men and women.11PubMed. Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women
Women tend to have smaller baseline creatine stores, partly because they typically carry less muscle mass and partly because of dietary differences, since creatine comes primarily from meat and fish. Whether this means the cardiovascular response to supplementation differs at higher doses or over longer periods has not been well studied. The limited data available suggests no sex-based difference in heart rate effects, but this is genuinely an area where more research involving women would be useful.
What the Rat Data Adds (and Where It Gets Complicated)
Most of the evidence discussed so far comes from human trials, which is where the practical answers live. But one animal finding is worth mentioning because it introduces a nuance the human data has not yet addressed. In rats that were both exercise-trained and supplemented with creatine, the hearts showed reduced tolerance to experimentally induced oxygen deprivation. Specifically, the hearts developed more contracture during simulated ischemia and recovered less output afterward, compared to hearts from exercise-trained rats that did not receive creatine.2PubMed. The effect of creatine supplementation on myocardial function, mitochondrial respiration and susceptibility to ischaemia/reperfusion injury in sedentary and exercised rats This was not observed in sedentary rats given creatine, only in the exercised group.
This finding has not been replicated in humans, and artificially clamping off blood supply to an isolated rat heart is a far cry from what happens in a living person. But it is a reminder that “safe for healthy people at standard doses” does not automatically mean “safe under every conceivable condition.” People with known coronary artery disease or a history of cardiac events should talk to their doctor before starting creatine, not because there is clear evidence of harm, but because the interaction between supplementation and compromised blood flow has not been thoroughly studied in humans.