The maximum amount of time one can be on the HCG diet using the HCG drops is 60 days plus maintenance. (When using injections, the maximum is 40 injections.) Those 60 days break down as follows: 2 days of fat loading, 55 days of VLCD, 3 days of transitional VLCD. The maintenance phase is 6 weeks long and is broken into two stages (M1 & M2), each lasting 21 days. The minimum is 21 days of VLCD and you can stop anytime up to 55 days on VLCD.