I agree about not taking Nytol one a night regularly. As for the 2-4 week point, thank your for raising that. From my understanding the reality is that Valerian may not work immediately for some people, which is why some manufacturers recommend taking it for a couple of weeks at least.f you have such bad insomnia, you might find a natural remedy like Nytol herbal doesn’t quite do it for you. It’s quite a mild sedative, and not for everyone. On the other hand, if you think it helped one night, then perhaps you might have some joy with it if you keep taking it for a few consecutive days.