Noble Formula Spray is our basic over the counter NF Spray with pyrithione zinc (ZnP) 0.25%. Maximum non-steroid medication without a prescription. NF Spray is great for itching, flaking, or inflamed scalp and skin issues caused by psoriasis, eczema, seborrheic dermatitis and other hyperkeratotic skin conditions. Good results are reported by most clients within 4-6 weeks of first application. No other non-prescription product is more effective. There is no special limitation on its use. Four-ounce bottle, with a fine mist sprayer.