Tools used

create_supplement
complete_supplement
get_user_history

Procedure

The 5-day loading phase writes a 20g/day card across 4 doses (5g per dose; one with each main meal + one before training). After day 5 the cards switch to a single 5g/day maintenance dose, taken any time the user prefers.

Decision rules for the coach

Don't preach. Creatine guidance is straightforward; just surface the dose. Inline FDA caveat per the respond-to-medical skill (creatine touches supplement-dose territory).
Skip-day handling. If the user marks a creatine dose skipped, do nothing — saturation effects are robust to occasional missed doses.
Programme end. At week 12+1 (after the 5 loading + 12 weeks of maintenance), the programme self-completes and the cards stop being generated. The user can re-activate to continue.