In our study we investigated the acute toxicity of а newly synthesized creatine lysinate as well as its effect on the biochemical parameters in mice. Creatine lysinate exerts better solubility in water (3.3%) in comparison to creatine monohydrate (1.4%) at 20 °C and it is determined as a non-toxic after intraperitoneal (LD50 – 4543 mg/kg) and oral administration (LD50 > 8000 mg/kg). Oral administration of creatine lysinate at doses of 3 g/kg/day and 6 g/kg/day for 2 weeks reduced the creatine kinase levels, which indicates muscle protection. An increased levels of liver enzymes like alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) was observed after the supplementation with creatine lysinate at both administered doses and the level of lactate was comparable both in the studied and the control group