Yes, hypnosis is safe. Your subconscious mind will not accept a suggestion that’s not safe for you or that you don’t want!
You should never listen to a hypnosis recording that tells you to close your eyes, or offers relaxation techniques, while you’re driving a car or doing something that requires your full attention.
If you want to use hypnosis for a medical condition, you should always consult your physician first. For example, you wouldn’t want to use hypnosis for headaches if they haven’t been properly diagnosed. What you might think is a simple headache or even a migraine headache could be your body warning you about a potential danger that only your physician can properly diagnose.