Yes, they are completely safe and effective. They are similar to hypnosis. Most of our recordings are recorded with binaural beats in the background. You may notice a slight deep hum. Those are the beats. They will place you in a very relaxed state where your subconscious mind will easily absorb the positive affirmations given to it.
Subliminals have been proven so effective the government banned them from early television commercials and movie theaters.