Creatine

How much did studies use?

NIH describes a common research protocol of 20 g daily in four portions for 5–7 days, followed by 3–5 g daily. Another approach uses about 3–6 g daily for several weeks without loading. These are studied protocols, not personal dosing instructions. 1

Loading is not necessary to fill muscle stores; it does so faster and may cause more stomach discomfort. Verbraucherzentrale describes stores filling after about 3–4 weeks at 3–5 g daily. 2

Weight gain and stomach discomfort

Water retention can raise body weight, and gastrointestinal discomfort can occur. These effects matter when interpreting an early change on the scale or considering sports where body weight affects performance. The German consumer guidance describes this water-related gain as distinct from gaining body fat. 2

Why can the kidney blood test change?

Creatinine is a breakdown product of creatine. A 2026 review of 26 studies involving 1,036 participants found higher blood creatinine and lower filtration estimates based on creatinine, but no significant difference when filtration was measured using Cr-EDTA. The authors interpreted the pattern as altered creatinine metabolism rather than evidence of kidney injury. 3

That distinction makes supplement use relevant when interpreting a blood test. It does not make any abnormal result harmless. Verbraucherzentrale advises medical guidance for people with existing disease, particularly kidney disease, and recommends telling the clinician about creatine use. 2

Who needs a separate safety assessment?

German consumer guidance advises that pregnant or breastfeeding people, children, adolescents and those with pre-existing illness should use creatine only following medical advice. Healthy-adult performance studies do not answer every question for these groups. 2