Despite being one of the most popular supplements in the world, many people know little about creatine.

For example, most have heard that creatine boosts performance, enhances muscle growth, and accelerates recovery. Still, few know how it works, how it’s made, which form is best, and so forth.

You’ll also often hear that creatine is linked to various negative side effects, like kidney damage, hair loss, and more.

In this article, you’ll learn science-based answers to the top 10 questions I get about creatine and its effects. 

1. How Does Creatine Work?

Adenosine triphosphate (ATP) is the most basic unit of cellular energy. When cells use ATP, they split it into smaller molecules, and when they’re finished, they “reassemble” the fragments back into ATP for reuse.

The more ATP your cells can store and the faster your body can regenerate ATP, the more “work” it can do. 

Creatine donates a molecule to an ATP precursor called adenosine diphosphate (ADP), which expedites ATP production, enabling your body to replenish its ATP store more rapidly. 

That’s why supplementing with creatine boosts muscle growth, increases strength and power, improves anaerobic capacity, reduces fatigue, lessens muscle damage and soreness after exercise, alters the expression of genes related to hypertrophy, and preserves muscle after grueling workouts.

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2. How Is Creatine Made?

Your body produces creatine in the kidneys and liver by combining the amino acids arginine, glycine, and methionine to create creatine phosphate and phosphocreatine, which it then stores in your muscles.

Supplement manufacturers produce creatine exogenously (outside the body) by combining, heating, and pressurizing sodium sarcosine and cyanamide (not to be confused with cyanide).

They then cool the resulting product, turning it into creatine crystals, which they purify using a centrifuge, vacuum dry, and mill into a fine powder, ready for use.

3. Which Creatine Is Best?

Creatine monohydrate is the most well-studied and scientifically supported sports supplement available today. Research repeatedly shows that creatine monohydrate is safe to use and reliably boosts your athletic performance as much or more than other forms of creatine. 

It’s also 3-to-5 times more affordable than other forms of creatine, making it the most cost effective.

Thus, creatine monohydrate is the gold standard of creatine, and nothing’s likely to dethrone it anytime soon. That’s why it’s the type I use in my creatine powder, gummies, and my post-workout supplement, Recharge.

(If you aren’t sure if creatine monohydrate powder, gummies, or Recharge is right for you or if another supplement might better fit your budget, circumstances, and goals, then take the Legion Supplement Finder Quiz! In less than a minute, it’ll tell you exactly what supplements are right for you. Click here to check it out.)

4. Can Creatine Expire?

Eventually, yes. 

That said, creatine monohydrate is exceptionally shelf stable and doesn’t degrade for several years, provided you keep it in cool, dry conditions. 

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5. Why Is Creatine Bad for You?

Some people believe creatine is bad for your kidneys, but this is a misunderstanding. 

If you have healthy kidneys, creatine doesn’t harm your kidneys.

Even if you have impaired kidney function, you’re unlikely to experience any problems. That said, consult your doctor before taking creatine if you have any questions or concerns about how it might affect your kidney health.

One of the reasons people believe creatine stresses the kidneys relates to a substance known as creatinine, which your body produces when it metabolizes creatine.

In sedentary people not supplementing with creatine, elevated creatinine levels can indicate kidney problems. You should expect high creatinine levels if you exercise regularly and supplement with creatine, though, and it’s not harmful in this case.

You may have also heard that taking creatine can lead to hair loss. 

One study conducted by scientists at Stellenbosch University found that creatine raised levels of dihydrotestosterone (DHT), a hormone that hastens hair loss in susceptible men.

Specifically, they found that the normal protocol of taking 20 grams of creatine per day for a week followed by 5 grams a day for 2 weeks increased DHT levels in male rugby players by about 40-to-60%.

That said, the study had several limitations (one being they didn’t actually measure hair loss, just a hormone often associated with it), and the results haven’t been replicated since. Thus, there’s very little evidence that creatine contributes to hair loss.

6. Are Creatine Capsules Good?

Yes, provided they contain 3-to-5 grams of creatine monohydrate per serving. 

They aren’t necessarily better than powdered creatine, but there’s nothing wrong with taking creatine in capsule or tablet form. 

7. Should You Take Creatine for Weight Loss?

Taking creatine probably won’t boost fat loss to a meaningful degree.

Still, supplementing with creatine while in a calorie deficit is smart because it helps you retain your muscle and strength, which is vital for improving your body composition. 

8. What’s the Best Creatine for Women?

The best creatine for women is creatine monohydrate.

And while we’re on the topic, women don’t have to worry that creatine will cause bloating or “make them bulky.” 

Bloating generally only occurs if you take a large dose of creatine all at once, which isn’t necessary to maximize its benefits and doesn’t occur in everyone, and getting bulky never was. 

(If you want more tips about the best way to train, diet, and supplement for females, check out my fitness book for women, Thinner Leaner Stronger.)

9. What’s the Best Creatine for Teens?

In the past, scientists have suggested—without scientific evidence or rationale—that teenagers who take creatine exhibit “unhealthy” or “disturbing” behavior similar to those who take anabolic steroids.

As a consequence, many health and fitness experts have been reluctant to recommend creatine supplementation to anyone under the age of 18.

However, most research on teenagers shows that creatine is well-tolerated and effective at boosting athletic performance. In other words, creatine seems to have similar effects in teenagers as in young, middle-aged, and older adults (which makes sense, since it’s basically just refined amino acids). 

Thus, the proper dose of creatine for teens is the same as for adults: 3-to-5 grams of creatine monohydrate daily. 

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10. What’s the Best Creatine for Runners?

Most research suggests that creatine isn’t particularly effective at improving endurance performance. 

This isn’t surprising given that your body uses a combination of glucose, glycogen, and body fat—not phosphocreatine—to fuel long-duration exercise.

As such, creatine isn’t as valuable to long-distance runners as to athletes who perform brief, intense bursts of effort (sprinters or powerlifters, for example).

That’s not to say creatine is useless for runners—it reduces soreness, muscle damage, and inflammation, protects against exercise-induced muscle breakdown, boosts recovery, and may enhance heat tolerance, which is beneficial if you race in hot, humid conditions. 

And if you want to make the most of these benefits, take 3-to-5 grams of creatine monohydrate daily. 

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