They tend to fade with time. How much varies from person to person, depends on how long it’s been since they’ve been used, and how strongly they were put in in the first place. Some triggers can last forever, but that generally requires them being reinforced a few times. Your mileage may vary 🙂

There are two kinds of post-hypnotic triggers.

The first I call “Training Triggers”, because they are only used during trance, or shortly after trance.

I set them once, and expect them to continue to work as long as the subject continues to regularly go into trance, whether with sessions or CDs. If they haven’t been in trance or used CDs for over a year, I assume I have to reset them. This includes the trance trigger (to bring the person into trance) and various feeling triggers, such as to feel a boost of confidence, calm, arousal, etc.

The second I call “Waking Triggers”. These are generally used while the person is awake and the hypnotist is not there. They may be used by the subject themselves, or someone they trust with their trigger.

Let’s take a silly example. Let’s say that I hypnotize someone to bark every time they hear the word “dog”, because that’s what the client wants, and they want this to be permanent. My rule of thumb is this: The first time I set it, it’ll probably work for the rest of the day, until they go to sleep. The second time, it’ll work for a few days to a week. And the third time, it will last for months, if not years.

Of course, you could also set a more useful triggers like

“I’ll feel a boost of super confidence every time I press my right thumb and index together”. Or, “I’ll feel super horny for my husband every time he calls me his Wild Kitten”.
“I’ll feel calm, sympathetic and interested in whatever my wife has to say whenever she starts with ‘Listen Honey…'”
If you’ve used substances to get high… well, you don’t need the substance more than once. You can reproduce the high at will. Cheap and legal! Hypnotists make lousy clients, as fas as dealers are concerned…
If you’ve ever felt something, you can feel it again with a trigger, and we can ramp it up to make it even stronger than the original experience.