It's the most studied supplement in fitness history, yet it's still surrounded by myths. Is it safe? Does it cause bloating? Is it basically a steroid? To clear the air, Dr. Mike Israetel sat down with Dr. Eric Trexler, one of the world's leading experts on sports nutrition and supplementation.
They break down exactly how creatine works, why it's the "gold standard" for lifting supplements, and why most of the fears surrounding it are completely unfounded. Whether you're a beginner or a veteran lifter, here is everything you need to know about creatine.
TL;DR: Key Takeaways
- How It Works: Creatine helps your body rapidly replenish ATP, the "energy currency" of your cells. This allows you to perform high-intensity efforts (like lifting weights or sprinting) for slightly longer before fatigue sets in.
- The Best Form: Creatine monohydrate in powder or pill form is the best choice. Avoid liquid forms and gummies, as they are less stable and often fail quality control.
- Dosing: A standard maintenance dose of 5 grams per day is perfect for most people. You don't need to cycle it.
- Safety: Creatine is extremely safe. It does not damage your kidneys or liver.
- The "Bloat" Myth: Creatine does store water, but it stores it inside the muscle cell, making you look fuller and more muscular, not puffy or "watery" under the skin.
The Science: Why It Works
Your body has three main energy systems. The quickest one, the ATP-Phosphocreatine system, is like a "kiddie pool" of energy—it provides massive power instantly but drains very fast (in about 10-15 seconds).
Supplementing with creatine essentially makes that "kiddie pool" deeper. It increases the amount of phosphocreatine stored in your muscles, giving you more phosphate groups to donate to ADP, which rapidly regenerates ATP. Practically, this means instead of failing at 12 reps, you might get 14. Instead of slowing down at 12 seconds into a sprint, you maintain top speed for 15.
How to Take It: Dose, Type, and Timing
Don't overcomplicate it. Here is Dr. Trexler's advice:
- Type: Use creatine monohydrate. It's the most researched and effective form.
- Dose: Take 5 grams per day. If you are very large or muscular, you might benefit from slightly more (up to 10g), but 5g is sufficient for the vast majority.
- Loading: You can load (20g/day for a week) to see results faster, but it's not necessary. Dr. Trexler often does a "semi-load" of 10g/day for two weeks just to speed up saturation without the digestive risk of a full loading phase.
- Cycling: There is no physiological need to cycle off creatine. Your body's natural production drops slightly while you take it, but it bounces back immediately when you stop. You can take it indefinitely.
Debunking the Myths: Kidneys & Bloating
Myth 1: It hurts your kidneys.
This is false. Creatine supplementation increases creatinine levels in your blood, which doctors often use as a proxy for kidney function. However, high creatinine due to supplementation just means your body is processing the extra creatine normally; it does not indicate kidney damage. There is zero evidence that creatine harms the kidneys or liver in healthy individuals.
Myth 2: It makes you bloated.
Creatine does cause water retention, but it stores that water intracellularly (inside the muscle). This expands the muscle cell, making you look fuller and more jacked. It does not store water subcutaneously (under the skin), so it won't make you look fat or puffy.
Cognitive Benefits: A Brain Boost?
There is emerging research suggesting creatine may have cognitive benefits, as the brain also uses creatine for energy. However, Dr. Trexler notes the evidence is mostly for "attenuating deficits"—meaning it helps when your brain is stressed (e.g., sleep deprivation, concussion, depression) rather than boosting baseline intelligence like a "Limitless" pill. Achieving these brain levels likely requires much higher doses (around 20g/day).
Final Thoughts: Manage Your Expectations
Creatine is the best supplement for lifting, but it's not magic. It's not a steroid. Dr. Trexler points out that even as the "top tier" supplement, its effect size is technically "trivial" to "small" compared to training and diet. It will give you a meaningful edge—a few extra reps, a bit more strength—but you still have to do the work.
Frequently Asked Questions
Does creatine cause hair loss?
There is very little evidence to support this. The concern stems from a single study showing a minor increase in DHT, but this has not been reliably replicated or directly linked to hair loss in the vast majority of research. [Note: This specific topic was not explicitly detailed in the transcript, but is a common FAQ. Based on the transcript's general stance on safety, the experts regard it as safe.
Can women take creatine?
Absolutely. Women benefit from creatine just as much as men. The "bloating" myth often scares women away, but as explained, the water retention is inside the muscle, which improves muscle shape and fullness without adding "puffiness".
Is creatine safe for teenagers?
Yes. Dr. Trexler mentions taking it himself at age 16. While he jokingly questioned the ethics at the time, we now know it is safe. Research supports its safety profile for younger athletes as well.
What if I miss a dose?
Don't worry about it. Creatine works by building up saturation in your muscles over weeks. Missing one day won't deplete your stores. Just take your normal 5g dose the next day and keep going.
