The Creatine and SHBG Connection: What the Research Shows
While creatine is a popular and well-researched supplement for boosting strength and performance, its influence on hormones, particularly sex hormone binding globulin (SHBG), is a point of confusion for many. Some of the concern stems from earlier, smaller studies that observed changes in hormone levels, while more comprehensive research presents a more nuanced picture. SHBG is a protein produced primarily by the liver that binds to sex hormones, including testosterone, making them biologically inactive. Therefore, an increase in SHBG can result in less free, or bioavailable, testosterone in the body.
One frequently cited study from 2004 examined the effects of creatine supplementation during short-term resistance training in men. In this trial, participants in the creatine group experienced a significant increase in SHBG levels compared to the placebo group. This change led to a decrease in the free androgen index (FAI), which is a ratio of total testosterone to SHBG. These findings suggested a correlation between creatine use and increased SHBG, but as we will explore, this is not the full story. Another similar study from 1999 also reported a significant increase in SHBG and a decrease in the FAI after 12 weeks of creatine supplementation combined with heavy resistance training.
The Role of DHT and Conflicting Evidence
Another dimension to the creatine and hormone conversation is its potential effect on dihydrotestosterone (DHT), a more potent form of testosterone. A 2009 study on male rugby players found that creatine supplementation significantly increased DHT levels after a loading phase, with elevated levels persisting through the maintenance phase. The researchers hypothesized that this was due to creatine increasing the conversion rate of testosterone to DHT via the enzyme 5-alpha reductase. This finding led to widespread concern, particularly regarding male pattern baldness, which is genetically linked to DHT levels.
However, later research has presented conflicting evidence, which casts doubt on the earlier findings regarding DHT.
- Several studies subsequent to the 2009 trial have failed to replicate the increase in DHT levels.
- A larger, double-blind study published in 2025 directly assessed creatine's effect on hair follicle health and found no significant changes in DHT levels or the DHT-to-testosterone ratio.
- Many experts now believe the original 2009 study had limitations, including a small sample size and short duration, which may have led to a misleading result.
Is Creatine a Steroid?
One common misconception is that creatine is an anabolic steroid. This is unequivocally false. Creatine is an organic compound made from amino acids and is naturally produced in the body. It works by increasing the availability of phosphocreatine in muscles, which helps regenerate ATP (adenosine triphosphate) for energy during high-intensity exercise. Anabolic steroids, by contrast, are synthetic derivatives of testosterone that bind to androgen receptors, directly influencing gene expression and significantly altering hormone levels. The difference in mechanism and chemical structure is significant. Creatine does not significantly alter hormone levels in a manner similar to steroids and is considered safe for most people when used responsibly.
Creatine's Effect on Women's Hormones
For women, the hormonal impact of creatine is different and generally considered beneficial or neutral. Unlike anabolic steroids, creatine does not adversely affect female hormones like estrogen. Research suggests creatine may support the body's systems that are sensitive to hormonal fluctuations, such as those that occur during the menstrual cycle, perimenopause, and menopause. By supporting cellular energy metabolism, creatine can help counteract some of the hormonal effects on energy levels, mood, and cognitive function. For example, studies suggest creatine can help with muscle preservation and bone density, particularly in post-menopausal women.
Comparing Creatine and Anabolic Steroids
| Feature | Creatine | Anabolic Steroids |
|---|---|---|
| Classification | Amino Acid Derivative | Synthetic Hormone |
| Mechanism of Action | Increases ATP availability for energy | Mimics testosterone, binds to androgen receptors |
| Effect on Hormones | Minor, complex, and potentially temporary effects on SHBG/DHT reported in some studies; not consistently replicated | Significant, direct alteration of hormone levels |
| Safety & Legality | Legal and widely considered safe for most users | Illegal without prescription; significant health risks |
| Side Effects | Water retention (initially), minor gastrointestinal issues possible | Liver damage, cardiovascular issues, significant hormonal imbalance, and more |
| Long-Term Effects | Well-researched, generally safe | Associated with high potential for abuse and long-term health risks |
Conclusion
While some initial studies did report an increase in SHBG and a subsequent decrease in the free androgen index with creatine supplementation, the evidence is not conclusive. The hormonal landscape is complex, and newer, more robust research often fails to replicate the significant hormonal shifts seen in earlier trials. The initial concern about creatine raising DHT levels, which stemmed from a single small study, has largely been debunked by more recent, larger-scale research. The key takeaway is that creatine is fundamentally different from anabolic steroids, acting on cellular energy pathways rather than directly altering hormone levels in a significant and potentially harmful way. For the vast majority of users, creatine remains a safe and effective ergogenic aid with minimal to no long-term adverse hormonal impact when taken at recommended dosages. Concerns should always be balanced with the full body of scientific evidence rather than relying on isolated or outdated findings. For any persistent hormonal concerns, consulting a healthcare professional is always recommended.
References
- The Effects of Creatine Supplementation on Muscular Performance and Resting Hormone Concentrations in an Overreaching Protocol - PubMed: https://pubmed.ncbi.nlm.nih.gov/14685870/
Authoritative Source
Key Takeaways
- Contradictory Evidence: Early, smaller studies suggested creatine can increase SHBG, but larger, recent trials often report no significant changes in sex hormone levels.
- Impact on FAI: If SHBG does increase, it would decrease the free androgen index, which reflects the amount of unbound, biologically active testosterone.
- DHT Controversy: The link between creatine and higher DHT levels, suggested by one small 2009 study, has not been replicated in more recent, larger trials.
- Not a Steroid: Creatine is an amino acid derivative, not an anabolic steroid, and does not operate via the same hormonal mechanisms.
- Generally Safe: When taken at recommended doses, creatine is considered a safe supplement with minimal to no long-term adverse effects on hormonal balance for most users.
- Women's Health: Creatine does not have a negative impact on female hormones and may support energy and mood, especially during hormonal fluctuations.
FAQs
Q: How do creatine and SHBG interact? A: While a few older studies have reported a temporary increase in SHBG with creatine use, particularly during intense training, most recent and larger studies have not found significant, lasting hormonal changes.
Q: What is the free androgen index, and why is it important? A: The free androgen index (FAI) is a ratio of total testosterone to SHBG. An increase in SHBG can decrease the FAI, meaning less testosterone is unbound and available to tissues.
Q: Does creatine cause hair loss by increasing DHT? A: The theory that creatine causes hair loss via DHT is based on a single, small 2009 study that has not been replicated. Recent, larger studies have found no association between creatine use and elevated DHT or hair follicle damage.
Q: Is creatine safe for women, and does it affect their hormones? A: Yes, creatine is generally safe for women. Studies show it does not negatively impact female hormones and can be beneficial for supporting energy levels during hormonal shifts, such as those in the menstrual cycle or menopause.
Q: Why is creatine sometimes confused with anabolic steroids? A: The confusion arises because both can enhance athletic performance and muscle mass. However, creatine is a natural amino acid derivative, while anabolic steroids are synthetic hormones with very different mechanisms and health risks.
Q: Should I worry about my hormone levels when taking creatine? A: For most healthy individuals taking recommended dosages, there is no strong evidence to suggest that creatine causes significant, adverse hormonal changes. However, if you have a pre-existing hormonal condition, it is best to consult a doctor.
Q: Does creatine affect cortisol levels? A: Some studies suggest creatine may help mitigate the rise in cortisol (a stress hormone) during high-intensity exercise, potentially aiding in faster recovery. However, research is mixed and individual responses may vary.
