But using it they are. According to the Mayo Clinic Sports Medicine Center in Rochester, Minn., an anonymous survey of teen athletes revealed that 8 percent are using creatine, often knowing little about it. You must feed your muscles a daily dose for them to both maintain and increase to high creatine levels. Is it safe for teens to supplement with creatine? Persistently high creatinine levels are most possibly caused. Join us, urinary tract infections can increase creatinine level in short time. 6.