PMS Rescue is a great aide for a woman's PMS aggravations. Gently assists in relaxing and destressing. Inhalers work by harnessing the therapeutic benefits of the essential oils used. Just hold under nose and inhale deeply several times. Made to order! Shelf life 4-6 months! Just toss in your purse and you'll have it available whenever needed. Not for pregnant women, children under 5, or women with female related cancers.