I use this product 3 times a week. Although some people have noted not getting any benefit from this product, I have many instances where this oxygen can did help. Used it after workouts, swimming laps, and recovery from stress in general. Positive results include clarity in thought, balance blood pressure, and a feeling of breathing in fresh air. If you ever feel like your going to pass out or faint, this will help tremendously.These results last up to 48 hours from 50+ deep breathes (hold oxygen for 15 seconds each breathe).depending on environmental air pollution, construction pollution, athletic activity, and drinking/smoking a person may need a daily dose.I am looking into recreational oxygen therapy machines but they are so expensive mostly, this is the most affordable supplemental oxygen option without a prescription.