How many years after first outbreak do frequent hsv outbreaks tend to subside to around 4 per year?

Hard to predict: Most people with frequently reucrring genital herpes experience gradually reducing frequency of outbreaks within 5-10 years. Any particular person may have a significant reduction after anywhere from a few months to several years; there's no way to predict. Valacyclovir or other anti-HSV drugs markedly reduce frequency of outbreaks and also helps prevent transmission to sex partners.