Creatine is naturally present mainly in animal-based foods. Red meat and fish are among the richest sources; poultry contains creatine as well but typically in lower amounts. Plant foods contain little to virtually no creatine, which is why vegetarians/vegans often have lower baseline muscle creatine stores and may respond more noticeably to supplementation. The amount you get from food varies with portion size and cooking; prolonged high heat can reduce content somewhat. In practice, regular meat/fish intake increases dietary creatine, while supplementation is often used for a more standardized intake—especially for performance goals. If you have kidney disease, are pregnant/breastfeeding, or use multiple medications, consult a clinician before starting.