Is it easier to use hypnosis for someone when they are tired?

It is easier to hypnotize someone when they are tired (the word Hypnosis comes from Hypnos, the Greek god of sleep)…

Keeping them in that state is more difficult as they tend to fall asleep and take more work on the hypnotherapist’s part.

Sessions are best done when the subject is more awake. While sleeping the critical conscious mind is completely moved out of the way - which allows for the absorption of the information into the subconscious mind to a degree, however it is reinforced better when there is more involvement with the conscious mind.

The conscious mind allows for active visualizations and other tools to help the information set in.