SupplementScience

Creatine Side Effects & Safety

DJP
Reviewed by , MD, Board Certified Internal Medicine

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Safety Profile

Overall safety rating: Generally Safe

Potential Side Effects

  • Water retention and weight gain (1-3 lbs, especially during loading phase)
  • Mild digestive discomfort at high doses (>10g single dose)
  • Muscle cramping (anecdotal — not supported by clinical data)
  • Rare: mild kidney stress in those with pre-existing kidney conditions

Drug & Supplement Interactions

  • NSAIDs (ibuprofen, naproxen) — theoretical increased kidney stress when combined
  • Caffeine may partially blunt creatine uptake during loading phase (evidence mixed)
  • Nephrotoxic medications — use caution if taking medications that stress the kidneys

Maximum Dose

Do not exceed: 5g/day for long-term use; 20g/day for 5-7 days during loading phase

Full Creatine Guide

References

  1. (). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition. DOI
  2. (). Effects of creatine supplementation and resistance training on muscle strength and weightlifting performance. Journal of Strength and Conditioning Research. DOI
  3. (). Effects of creatine supplementation on cognitive function of healthy individuals: A systematic review of 6 randomized controlled trials. Experimental Gerontology. DOI