For maximum muscle gains and fat loss, it is always best to "cycle" supplements. In other words, you take 1,2 or a few products for a maximum of 2 months, then you have at least 1 month's break.
During your break time, you can either take nothing or take other products for more gains (or fat loss).
So a "cycle" is either 1 or 2 months of being on the same product or product combination.
You can also combine supplements, which means taking several supplements at the same time.