A sports supplement is a dietary supplement used by athletes in the hope of enhancing performance, a vast market spanning the proven, the plausible, and the preposterous. Creatine and caffeine have solid evidence for strength and endurance respectively; protein powders help those struggling to meet high requirements; bicarbonate and beta-alanine buffer the burn of intense effort. Beyond these, most products rest on thin evidence, aggressive marketing, and the placebo effect, while some carry real risks of contamination with banned substances that end careers. Athletes are advised to prioritise food first, check third-party testing, and remember that no supplement compensates for inadequate training, sleep, or diet. The industry sells shortcuts; physiology rarely offers them.