A more thorough explanation:

Definition:

Take effect (verb) - to become active or start working as intended.

Examples:

• After taking the medicine, it will take effect in about 30 minutes.
• The new law will take effect on January 1st.
• Once the contract is signed, it will take effect immediately.

Explanation: When something takes effect, it means that it becomes active or starts working as intended. In the first example, the medicine needs time to start working in the body. In the second example, the new law will become enforceable on a specific date. In the third example, the contract will become valid and enforceable as soon as it is signed.