What is creatine, and should you take it? Why it’s not just for bodybuilders, and never really was 

What is creatine, and should you take it? Why it’s not just for bodybuilders, and never really was 

Beyond the buzz: why creatine is evolving from a sports supplement into a widely studied tool for muscle strength and mass

In the mid-1990s, if you walked into a gym, you’d likely see tubs of creatine powder with shaker bottles and hear conversations about “gains.” Since then, creatine - more clinically, and officially, creatine monohydrate - has remained one of the most widely used sports supplements in the world. 

More recently, however, it has moved beyond bodybuilding circles into everyday conversations. From young adults focused on strength training to those over 40 looking to maintain muscle as they age, many are asking: What exactly is creatine? Do I need it? And how should I use it?  

Part of this surge is driven by the depth of research behind it, along with growing interest in strength as a foundation for healthy aging. Creatine monohydrate is the most studied performance supplement today, and since the 1970s, more than 500 peer-reviewed clinical trials have examined the supplement. Therefore, the evidence is strong on creatine monohydrate for improving multiple aspects of health, including increased strength and power, preservation of lean muscle mass, and enhanced performance. There has also been preliminary research exploring its potential role in brain health, sleep deprivation, chronic stress management, and even depression and anxiety.  

But, as with most trending topics, misinformation persists. Some believe creatine monohydrate is only relevant for men or athletes, while others may have bought in to an outdated idea that proliferated from inaccurate research that it causes kidney damage.  

This article draws on insights from Medcan’s Clinical Director of Food and Nutrition, Leslie Beck, RD, along with Medcan’s Clinical Director of Sports Therapy and Rehabilitation, Dr. Miners, to provide clear, evidence-based guidance on whether creatine monohydrate has a place in your health routine.

What is creatine and how does it work?  

Creatine is a naturally occurring compound that helps your body produce energy quickly. It’s made in the liver and kidneys, with about 95% stored in skeletal muscle as phosphocreatine, a higher-energy form of creatine. The remaining 5% is found in the brain and other tissues. 

When your body needs a rapid burst of energy during weightlifting, sprinting or other high-intensity efforts, creatine helps meet that demand. One simple way to think of it is as your body’s backup battery. 

Your cells rely on a molecule called adenosine triphosphate (ATP) as their primary energy source. ATP is what allows you to move, think, and function. But during short, intense efforts, your muscles use ATP in seconds. This is where phosphocreatine comes in. It helps regenerate ATP by donating a phosphate, allowing you to maintain high-intensity output for a little longer. 

Over time, that added capacity can translate into measurable improvements in: 

• Endurance: you get more total work in a training session 
• Strength: you gain an increased ability to lift slightly heavier weights or complete more repetitions 
• Power: you perform better in repeated sprints or explosive movements 

These small gains, repeated over weeks and months, can drive meaningful increases in strength and muscle mass and enhance your performance in all areas. Research shows that creatine monohydrate – the supplemental form of creatine –  can help you achieve the following benefits: 

• Strength and muscle gain: when paired with progressive resistance training, creatine consistently improves strength and lean mass compared with training alone. 
• High intensity performance: activities that involve short bursts of effort, such as sprinting, jumping or repeated shifts in team sports, often improve with creatine. 
• Healthy aging and function: for older adults, creatine paired with strength training can support muscle, bone loading and functional capacity – such as getting up from a chair or climbing stairs. 
• Muscle maintenance during dieting: in calorie deficits, creatine may help preserve muscle mass when combined with adequate protein and resistance training. 
• Boosting energy during periods of intense stress or sleep deprivation: stress and lack of sleep can disrupt regular creatine synthesis. Therefore, creatine supplementation may be helpful for boosting energy during these periods. 

These benefits become more evident when you understand how the body gets creatine monohydrates and what can disrupt health processes. 

How does your body get its creatine, and what disrupts healthy synthesis? 

According to Leslie, “Most people consume about 1-2 grams of creatine monohydrate per day through food, primarily from beef, pork, lamb, fish and shellfish. The body also produces roughly 1 gram daily." Together, this is enough to support normal function, assuming your body is operating optimally and your environment supports it. 

However, there are three key factors that can disrupt healthy creatine synthesis: 

1. Aging 
2. Sleep deprivation 
3. Stress 

Aging 

As you get older, creatine synthesis may decline. Since creatine is produced mainly in the kidneys and liver, age-related changes in these organs can reduce efficiency. At the same time, natural muscle loss can lower the body’s total creatine stores and its ability to recycle and use it effectively. 

Aging is also associated with increased oxidative stress, inflammation, and metabolic changes. These shifts can raise energy demands while reducing efficiency. Your body may develop a greater reliance on creatine but a diminished ability to maintain optimal levels. 

Sleep deprivation 

Research suggests that sleep deprivation alters creatine biomarkers, which means your body may not regulate or use creatine as efficiently when you’re sleep deprived. Poor sleep also affects ATP and phosphocreatine systems in the brain by increasing demand while accelerating depletion. Since creatine helps buffer energy in the brain, disruptions in sleep are also linked to reduced cognitive performance and changes in energy metabolism. 

Chronic stress 

Chronic stress may further impair creatine production. Elevated cortisol can increase the breakdown of protein, disrupt liver function, and interfere with methylation (a normal body process that turns genes on and off and helps your body respond to its environment) - all processes related to creatine synthesis.  

This is where supplementation may be helpful beyond athletic performance.  Still, whether it is worth considering depends on your goals, diet, age, and overall health.  

What creatine will not do for you: 

• Replace a structured training program 
• Compensate for poor sleep, high stress or inadequate nutrition 
• Turn endurance athletes into sprinters 
• Deliver instant results without consistent effort 

According to Dr. Miners, “Creatine always works best when it supports, rather than replaces, the fundamentals of training, nutrition and recovery.” 

So, should you take creatine?  

Certain groups may benefit greatly from a creatine monohydrate supplement. Evidence shows the best candidates may be:  

• Strength and power athletes: people who lift weights, sprint or play sports that involve repeated high-intensity efforts often see improvements in strength, power and training volume. 
• Recreational exercisers focused on muscle: adults who train consistently and want to support lean muscle, especially during calorie deficits, may benefit. 
• Older adults (50+): when combined with resistance training, creatine monohydrate may help preserve muscle mass and strength, which are critical for mobility and independence with age. This includes both men and women. The strongest aging-muscle data come from studies conducted in adults ages ≥ 50, often 60+ and postmenopausal women participating in resistance training. 
• People with low dietary creatine intake: vegetarians and vegans typically have lower baseline creatine stores because plant foods contain very little creatine. They may see a more pronounced response to supplementation. 
• People with rare genetic creatine synthesis disorders. GAMT deficiency (short for guanidinoacetate methyltransferase) is a creatine synthesis condition that impacts approximately 1 in 250,000, but it has no symptoms and lack of screening that number may be more. 

Creatine is exceptionally well tolerated in healthy individuals when used at recommended doses. Only a select few may need to be cautious. Those who fit the below description should speak with a physician before starting creatine monohydrate.: 

• Have kidney disease or reduced kidney function: creatine is broken down into a compound called creatinine, which is filtered out by the kidneys. If kidney function is already impaired, adding more creatine can increase the kidneys’ workload and may complicate monitoring (since creatinine levels are also used to assess kidney health). 
• Take medications that affect kidney health: some medications already put strain on the kidneys or alter how they function. Taking creatine alongside these could increase that strain or make it harder to tell whether changes in kidney markers are due to the medication or the supplement. 
• Complex medical conditions or multiple medications: if someone has multiple health issues or takes several medications, there’s a higher chance of unexpected interactions or side effects. Even if creatine is generally safe, it’s important to make sure it fits within the bigger picture of their health and treatment plan. 

According to Leslie, “Creatine monohydrate is considered generally safe and well tolerated with studies conducted in adults that have lasted up to five years. However, there’s limited evidence about the safety of creatine supplements in children and adolescents.” 

If you are unsure where you stand, a comprehensive check‑in, such as Medcan’s Annual Health Assessment, can help clarify your baseline health and whether supplements like creatine fit into your overall plan. 

How to use creatine safely and effectively 

If you decide creatine monohydrate aligns with your goals, using it correctly matters. Leslie recommends choosing a high-quality source. “While other forms exist, monohydrate is the most studied, so look for that on the label.” 

Other forms are available, but none have consistently outperformed creatine monohydrate in high-quality trials. “It’s also important that the product is third-party tested,” adds Dr. Miners.  

Look for a recognized seal of approval to ensure quality and purity. The biggest indicator is an official third-party logo printed on the front or back of the package. Common ones include: 

• NSF Certified for Sport 
• Informed-Sport or Informed-Choice 
• USP Verified (U.S. Pharmacopeia) 
• BSCG (Banned Substances Control Group) 

These logos mean the product has been independently tested for purity (what’s on the label is actually in the product), contaminants (heavy metals, microbes) and banned substances (especially important for athletes). 

How much creatine should you take?

For most healthy adults, Leslie recommends 3 to 5 g/day of creatine monohydrate per day. This is evidence-based and sufficient for maintenance once muscle stores are saturated.  

Some studies in older adults have used weight-based doses around 0.1 g/kg/day (often about 7 to 9 g/day) but there is not strong evidence from randomized controlled trials showing these doses are more effective than 5 g/day for muscle gains when combined with resistance training. According to Leslie, “Higher creatine doses have also been studied for sleep-deprivation-related cognitive performance, but this evidence is early, short-term and not strong enough to recommend higher doses for those with chronic stress or poor sleep.” 

There is also a traditional 20 g/day loading two-phase dose approach for creatine monohydrate that is well established as a short-term way to saturate muscle creatine stores faster, followed by 3–5 g/day for maintenance. A loading phase approach is as follows: 

• Phase 1 (loading): 20 grams per day, split into four doses, for 5–7 days 
• Phase 2 (maintenance): 3–5 grams per day 

For most people, however, a no-loading approach is simpler and reduces the likelihood of mild gastrointestinal discomfort. 

Creatine monohydrate can be taken with a meal to support absorption and reduce stomach upset, or mixed into water, juice, a smoothie or a post-workout shake. And since creatine draws water into muscle cells, staying well hydrated is important. Aim for consistent fluid intake throughout the day, especially if you are training in warmer environments. 

Timing is flexible, but consistency is key.  Missing a day occasionally is not a concern, but regular use is needed to maintain elevated muscle stores.  

Side effects and safety 

Research shows that long-term use of creatine monohydrate is well-tolerated and safe for most people who are focused on building muscle strength and mass. There are, however, minor side effects. Here are the three most common ones: 

1. Mild water retention that may show up as a small increase in body weight  
2. Occasional stomach upset 
3. Elevated creatinine  

Mild water retention 

Creatine pulls water into muscle cells, which can cause a slight increase in body weight or a feeling of fullness. However, this effect is short-lived. “After the first week, as you move into a maintenance dose, fluid balance stabilizes, and the water is retained in the muscle rather than under the skin,” explains Dr. Miners. 

For those who prefer to avoid mild water retention, a lower, gradual dosing can help. But this also means it will take longer to fully saturate muscle stores and realize the same performance benefits. 

Occasional stomach upset 

Stomach upset can happen if large doses are taken at once. To reduce the risk, split your intake into smaller doses throughout the day rather than taking it all at once. 

Taking creatine with food can also help improve tolerance, as can mixing it thoroughly into fluid to ensure its fully dissolved. For some, starting with a lower daily dose (rather than loading) and gradually increasing over time can minimize digestive discomfort while still allowing muscle stores to build. 

Elevated creatine 

If you’re taking creatine, it’s important to know that it can affect certain lab results, particularly creatinine levels. Creatinine is a breakdown product of creatine, and it’s commonly used as a biomarker of kidney function. (Creatinine is one of the 100+ biomarkers we test for as part of your Annual Health Assessment). 

When you supplement with creatine, research shows that creatinine levels may appear slightly elevated on blood tests. This does not necessarily indicate kidney dysfunction. In many cases, it reflects increased creatine intake rather than a true issue with filtration. 

However, because creatinine is used clinically to assess kidney health, it’s important to let your healthcare provider know if you are taking creatine so they can interpret your results accurately. Those with underlying kidney issues should also only use creatine under medical supervision. 

Practical steps for starting creatine 

The decision to use creatine should start with a simple question: what am I trying to achieve? If you are considering creatine, a structured approach can help you use it safely and effectively. 

Step 1: Clarify your current health status 

Before adding any supplements, you want to understand your baseline health. Consider: 

Recent blood work, including kidney function 

• Current medications and medical conditions 
• Your training history and injury profile 

A comprehensive evaluation, such as an Annual Health Assessment, can help you identify any red flags and ensure your supplement choices align with your broader health picture. 

Step 2: Define your training and nutrition plan 

Creatine works best when it supports a clear plan. Map out: 

• How many days per week you will train 
• The type of exercise you will focus on (for example, resistance training) 
• Your protein intake and overall nutrition 

If you are unsure how to structure your workouts, partnering with a trainer as part of Medcan’s Personalized Fitness Training can help you build a fitness program that makes effective use of tools like creatine. 

Step 3: Start low, monitor and adjust 

Begin with 3–5 grams of creatine monohydrate per day, taken with food. Over the first few weeks: 

• Monitor how you feel, including digestion and energy 
• Track training performance and recovery 
• Keep an eye on body weight and hydration 

If you notice persistent discomfort, pause and speak with a healthcare professional.  

Step 4: Reassess regularly 

Supplements should be reviewed periodically. Every few months, ask: 

• Is creatine helping me move toward my goals? 
• Has my health status or medication changed? 
• Do I still need or want to continue? 

Building in regular check‑ins with your care team helps ensure creatine remains a supportive, not central, part of your health strategy. 

If you are working with a trainer or coach as part of Medcan’s Personalized Fitness Training, integrating creatine into a broader plan that includes structured exercise can help ensure you are using it to support clear, realistic goals. 

Take action 

Think creatine might be right for you? You can discuss creatine with a nutrition or fitness consultant as part of your Annual Health Assessment. Medcan’s Annual Health Assessment tests for over 100 biomarkers and includes up to 15 screening stations. This comprehensive evaluation will give you a baseline of your overall health and the opportunity to discuss your health and fitness goals to decide if creatine may be a useful supplement. Explore Medcan’s Annual Health Assessment. 

For more personalized nutrition guidance and ongoing support, consider Medcan’s personalized Nutrition Programs. Developed by Leslie Beck, RD, Medcan’s Clinical Director of Food and Nutrition and one of Canada’s leading dietitians, these programs provide tailored support through customized meal plans, regular follow-up appointments, education, coaching, and accountability to help you achieve your health goals. Find out more now. 

Medcan's Personalized Fitness Training Program also offers a comprehensive approach to help you achieve your health and wellness goals, whether you are an exercise novice or a professional athlete. Working with a personal trainer can help you decide if creatine is right for you. Learn more here. 

This article was written by Medcan's editorial team with review and contribution from Medcan's Clinical Director of Food and Nutrition, Leslie Beck, RD, and Clinical Director of Sports Therapy, Rehabilitation and Fitness, Dr. Andrew Miners.

Note: This information is intended for educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment.