How long the effects of cryotherapy last depends on the benefit you’re looking at. The initial boost in mood and energy lasts several hours, and so does the increased metabolic rate as your body tries to warm back up to normal temperatures.  Some of the benefits that require repeat cold exposure (such as improved collagen production and skin health) last for longer, but they’ll likely fade if you stop the treatment — unless you also make other lifestyle changes (i.e., changing your diet) that reduce inflammation and promote collagen production.