The Basic Custom Homeopathic is a dual system, Build and Detox: Phase 1 and Phase 2. The difference is that Phase 1 initiates the detox process while boosting the immune system, Phase 2 will dig deeper to detox and is only effective if Phase 1 is initiated first. Each 4 oz bottle is enough for 2 months, you will receive Phase 1 first and then Phase 2 two months later.