This warning does not mean that creatine has been proven harmful to adolescents, but rather reflects a precautionary approach due to a lack of long-term pediatric safety research (Jagim & Kerksick, 2021). Most existing safety data on creatine comes from studies on adults, which is why manufacturers and AdvancedU recommend consulting a doctor or sports professional before use for those under 18 (or under 16 for this product). This is a conservative warning, not proven risk for this age group.

3 g per day is the lower limit of the maintenance range recommended by the ISSN position stand (Kreider et al., 2017) – within this range, the dose is clinically effective, only that without an initial loading phase (where you would take around 20 g/day for a few days), it takes longer, approximately 3-4 weeks, for muscles to reach full creatine saturation. If you want faster results, you can increase the dose in the first days (after consulting a professional), otherwise 3 g/day with consistent long-term use is a fully sufficient maintenance dose.

In terms of effect, there is no difference – creatine monohydrate in capsules and in powder has the same bioavailability, since it's the same active substance, just a different dosing form (Kreider, Jäger & Purpura, 2022). Capsules are more convenient for travel and don't require mixing, but they are often more expensive per gram of creatine and sometimes require taking multiple capsules for the same dose. The choice is therefore a matter of convenience, not effectiveness.

If you have an existing kidney disease, we advise against starting creatine on your own without prior consultation with a doctor. Although reviews in healthy adults find no evidence of harm from standard doses (Longobardi et al., 2025), this data was obtained from individuals without pre-existing kidney conditions, so there isn't enough specific safety data for those who already have kidney disease. A doctor can assess your condition and, if necessary, monitor kidney function using markers that are not dependent on creatinine.