Pure, from the ground, plants distilled into oil DO NOT expire and can last for centuries. Essential oil is not a perishable item. If oils come from plants (as long as they are contained) they maintain bio-activity, safety, and efficacy. They don’t grow mold, yeast, or mildew because they don’t contain water and have antimicrobial, anti-viral properties.
Young Living has a date stamp on every label; yr/m/d. They stamp when the product is bottled and can trace back to a particular batch of essential oil (through the seed to seal process) with that stamp. (Read about the seed to seal process here.)
Not even heat can affect the molecular properties of the oils. Heat will only affect the rapidity of the evaporation process. Evaporation does not affect its molecular properties, it will only affect the volume. In a pure oil, the monoterpenes are going to evaporate first (because they are lighter molecules), and the sesquiterpenes will remain. When a person leaves a bottle open and oil has evaporated slightly, it was the monoterpenes evaporating. They’ll even evaporate slowly through the plastic caps and leave the sesquiterpenes behind. But that’s ok, the sesquiterpenes are the powerhouse of the oil. They’re the bioactive power of the oil.
Essential oils have been unearthed in jars in Egypt and were still usable and sesquiterpene rich. Dr. Woolley found frankincense resin in the sands of Oman and there was still oil in the resin even after 65+ years of being buried. Resin itself can stay in the Omani market for 5-10 years and still maintain its properties.
So think again if your oils have an expiration date on them. Question the quality of your product! Remember that pure, from the ground, plants distilled into oil DO NOT expire!Source
What about YOU? Do the oils in your cabinet have an expiration date?