Do creatine and protein supplements affect seminal fluid composition or fertility?

Effects of Creatine and Protein Supplements on Seminal Fluid and Ejaculate

There is no evidence that creatine or protein supplements significantly alter seminal fluid composition or affect fertility in men. Based on available guidelines and research, these supplements do not appear to have direct effects on ejaculate quality or fertility outcomes.

Seminal Fluid Composition and Supplements

• Current medical guidelines do not identify creatine or protein supplements as factors that alter seminal fluid composition 1
• Seminal plasma hypersensitivity (allergic reactions to semen) is a documented condition but is unrelated to dietary supplements and is not associated with infertility 1
• While various factors can affect male fertility, dietary supplements such as creatine and protein are not mentioned in fertility guidelines as having significant impacts on semen parameters 1

Creatine Supplementation and Hormonal Effects

• One study found that creatine supplementation may increase the dihydrotestosterone (DHT) to testosterone ratio in young male athletes after 3 weeks of supplementation 2
• This hormonal change showed a 56% increase in DHT after 7 days of creatine loading, with levels remaining 40% above baseline after maintenance dosing 2
• However, this study did not evaluate effects on seminal fluid composition or fertility parameters 2

Protein Supplements and Male Fertility

• Guidelines on male infertility indicate there is insufficient evidence to recommend protein or other dietary supplements for improving male fertility 1
• The American Urological Association (AUA) and American Society for Reproductive Medicine (ASRM) state that "the benefits of supplements (e.g., antioxidants, vitamins) are of questionable clinical utility in treating male infertility" 1
• Current evidence does not support that protein supplements have any direct effect on semen parameters or ejaculate composition 1

Body Composition Effects vs. Reproductive Effects

• Research on creatine and protein supplementation has primarily focused on body composition and strength outcomes rather than reproductive parameters 3, 4
• Studies show these supplements may affect lean body mass but do not document changes to seminal fluid 3, 4
• When combined with resistance training, neither creatine nor protein supplements showed additional benefits beyond exercise alone in middle-aged and older men 4

Safety Considerations

• The primary safety concerns with creatine supplementation relate to kidney function in those with pre-existing renal disease, not reproductive health 5
• No evidence suggests that standard doses of creatine or protein supplements negatively impact male reproductive function 1
• While creatine has been proposed as a potential component of paternal preconception diet due to its role in sperm energy metabolism, conclusive evidence of benefit is lacking 6

Clinical Implications

• For men concerned about fertility, focus should remain on established factors that affect semen quality such as smoking, excessive alcohol, certain medications, and environmental exposures 1
• Current fertility guidelines do not recommend routine use of dietary supplements including creatine or protein for improving male fertility 1
• Men with fertility concerns should consult with reproductive specialists for appropriate evaluation rather than relying on unproven dietary interventions 1