PROBLEM TO BE SOLVED: To provide L-carnitine having a configuration exhibiting high bioavailability by oral administration, and its salt; to provide L-carnitine having a configuration easily preparable by combining another component (for example, an oil-based material) incapable of blending with L-carnitine of bulk, and its salt; and to provide L-carnitine having a configuration exhibiting low hygroscopicity, and its salt.SOLUTION: L-carnitine provided has a particle size such that it substantially passes through a 100 USBS mesh sieve. The L-carnitine exhibits increased bioavailability and low hygroscopicity and may be conveniently formulated with oil-based materials to give a drug product. The L-carnitine and its salt have a novel configuration exhibiting high bioavailability by oral administration.【課題】経口投与で高い生物学的利用能を示す形態のL-カルニチン及びその塩の提供。バルクのL-カルニチンを混和させ得ない他の成分(例えば油性原料)と組合せて容易に調合され得る形態のL-カルニチン及びその塩の提供。低吸湿性を示す形態のL-カルニチン及びその塩の提供。【解決手段】実質的に100USBSメッシュの篩を通過する粒子サイズを有するL-カルニチン。当該L-カルニチンは、向上した生物学的利用能と低吸湿性を示し、好便に油性材料と組合わせて製剤化することができる。本発明の目的は、経口投与で高い生物学的利用能を示す新規な形態のL-カルニチン及びその塩を提供することにある。【選択図】なし