What is Creatine and How Does it Work?
Creatine is a naturally occurring compound synthesized in the kidneys, pancreas, and liver from the amino acids arginine, glycine, and methionine. It is also obtained from dietary sources like red meat and fish. Most of the body's creatine is stored in skeletal muscle as phosphocreatine, which plays a crucial role in rapidly generating adenosine triphosphate (ATP), the primary energy currency of cells.
When you engage in high-intensity, short-duration exercise, your body uses ATP for energy. Creatine supplementation increases the body's phosphocreatine stores, allowing for faster and more efficient ATP regeneration. This cellular energy boost is the primary mechanism behind creatine's well-documented ergogenic effects, including increased muscle strength, power, and exercise performance.
The Source of the Creatine-Testosterone Myth: The 2009 DHT Study
The widespread belief that creatine increases testosterone largely stems from a single study published in the Clinical Journal of Sport Medicine in 2009. In this double-blind, placebo-controlled crossover study, 20 college-aged male rugby players took creatine monohydrate for three weeks, including a loading phase.
The study found no significant change in serum total testosterone levels. However, it did observe a temporary increase in dihydrotestosterone (DHT), a more potent androgenic metabolite of testosterone. Specifically, DHT levels increased by 56% after a seven-day loading period and remained 40% above baseline during the maintenance phase. This finding was statistically significant compared to the placebo group.
Separating DHT from Testosterone
To understand why this finding doesn't mean creatine boosts testosterone, it's essential to know the difference. Testosterone is the primary male sex hormone, while DHT is a more potent androgen derived from it by the enzyme 5-alpha-reductase. DHT is linked to the development of male characteristics and, in susceptible individuals, is implicated in male pattern baldness.
The 2009 study’s findings suggested that creatine might increase the conversion rate of testosterone to DHT, but it did not increase the total pool of testosterone. This is a crucial distinction that was often overlooked in popular media and online discussions, which frequently confused the two hormones.
The Broader Scientific Consensus on Creatine and Hormones
Since the 2009 study, numerous other research investigations and systematic reviews have failed to replicate the significant DHT increase, and most show no effect on total testosterone. For example, a 2021 review covering 12 different studies on creatine and testosterone found that 10 of them showed no significant change in testosterone concentrations. A 2025 randomized controlled trial also found no significant changes in testosterone, free testosterone, or DHT after 12 weeks of creatine supplementation.
Intense resistance training itself can cause temporary fluctuations in hormones, and some studies have shown acute, post-exercise increases in testosterone that are independent of creatine supplementation. While creatine enhances training performance, leading to greater training volume and intensity, it's the intense exercise—not the creatine itself—that is primarily responsible for these hormonal changes.
Actual, Proven Benefits of Creatine
Instead of acting as a hormonal agent, creatine's benefits are primarily linked to cellular energy and muscle performance. These include:
- Enhanced Exercise Performance: Improves capacity for high-intensity, short-duration exercise, allowing for more reps and sets.
- Increased Lean Muscle Mass: When combined with resistance training, it has been shown to increase muscle mass, partly due to cell volumization (water being drawn into muscle cells).
- Faster Muscle Recovery: Reduces muscle damage and helps with faster healing and recovery between workouts.
- Improved Brain Function: Research indicates potential benefits for cognitive performance, including short-term memory and reasoning, particularly in situations of mental fatigue.
- Potential Benefits for Aging: Helps combat age-related muscle loss and improves bone density, especially in post-menopausal women.
Creatine vs. Anabolic Steroids: A Crucial Distinction
It's important to differentiate creatine from anabolic steroids. Anabolic steroids are synthetic versions of testosterone that can significantly and often negatively impact hormonal balance. In contrast, creatine is not a hormone and does not work through hormonal pathways to build muscle. Its mechanism is based on improving cellular energy, making it a completely different class of supplement with a far safer profile.
Comparison Table: Creatine Myths vs. Scientific Facts
| Aspect | Claimed Myth | Scientific Fact |
|---|---|---|
| Effect on Total Testosterone | Significantly increases total testosterone. | No significant increase found in most research, including long-term studies. |
| Effect on DHT | Always causes a significant and sustained increase in DHT. | One 2009 study showed a temporary increase in DHT, but this was not consistently replicated in subsequent, more robust trials. |
| Mechanism for Muscle Growth | Works like a steroid to directly influence hormonal signaling. | Increases muscle mass by improving cellular energy production and causing cell volumization. |
| Safety and Hormones | Unsafe for hormonal balance, especially long-term use. | Considered safe for long-term use in healthy individuals, with no evidence of disrupting hormone balance. |
| Relationship with Exercise | Increases hormones independently of exercise. | May slightly augment hormonal responses following exercise, but the training itself is the primary driver of hormonal changes. |
Conclusion
The scientific community has largely debunked the notion that creatine significantly increases testosterone. The widespread misconception originated from a single, small study in 2009 that showed a temporary spike in DHT, not total testosterone. Since then, numerous robust studies have found no significant hormonal effects from creatine supplementation. The supplement's benefits—increased strength, improved performance, and enhanced recovery—are well-established and come from its role in cellular energy metabolism, not from acting as a hormone booster. For a safe and effective performance enhancer, creatine remains a top-tier choice based on decades of research. Those interested can review the consensus from the International Society of Sports Nutrition regarding its safety and efficacy.
