You can take creatine without working out, but you may not get its main benefits. Creatine supplementation works best when combined with exercise, because physical activity increases muscle uptake and helps improve muscle performance.
There is no clearly defined ideal daily dose, but any excess creatine that is not stored in the muscles appears to be removed by the kidneys through urine.
For healthy people, creatine is not believed to harm the kidneys when used at recommended doses. While creatine may have other possible benefits, more studies are needed before it can be recommended for other purposes.
To use creatine safely and effectively, talk to a doctor or registered dietitian.