Whether or not nootropics will break your fast depends on the specific nootropic and the type of fast you are following.
If you are following a water fast, which involves abstaining from all food and drinks except for water, then any supplement, including nootropics, would break your fast.
If you are following an intermittent fasting (IF) protocol that allows for the consumption of certain foods or drinks during the fasting period, then it's important to consider the specific nootropic and its ingredients. Some nootropics may contain calories, such as those that are mixed with sugar or other sweeteners, which can break your fast. Other nootropics may be calorie-free and not affect your fasting state.
It's important to note that the effects of nootropics on fasting are still being studied, and more research is needed to determine if they have any potential benefits or negative effects on fasting. If you are considering taking a nootropic while fasting, it's important to speak with a healthcare professional to determine if it's safe and appropriate for you, and to carefully research the specific nootropic and its ingredients to determine if it may break your fast.