first of all it if they're the correct red bulbs and I'll mention the ones that I've been using in a moment they uh eliminate all the blue wavelengths that tend to be stimulating for the what we call the noradrenergic system so adrenaline noradrenaline cortisol Etc indeed there's a study shows that when shift workers who have to be up at night use red lights of the type that I'm describing when they work under red light they have less of a cortisol increase than were they to work under standard fluorescent lights or even standard LED lights