Wellness
Does Rosemary Oil Expire? Storage and Shelf-Life Guide
Like other oils, rosemary oil can change over time, especially when exposed to air, heat and light. The biggest concern is oxidation, which happens when oxygen gradually breaks down the oil. An oxidized oil may smell different, become less pleasant to use and be more likely to irritate sensitive skin.
How long rosemary oil lasts depends on what you’re actually using. A bottle of rosemary essential oil isn’t the same as a rosemary-infused carrier oil or a finished scalp product containing rosemary. Ingredients, packaging and manufacturing all affect shelf life, so the manufacturer’s label should be your first source of information.
Check the Label First
If your rosemary oil has an expiration date, use that as your guide. Some cosmetic products instead use a PAO, or period-after-opening symbol, which looks like a small open jar with a number followed by the letter “M.” For example, “12M” generally means the product is intended to be used within 12 months after opening.
Some products may also have a batch or lot code that helps the manufacturer identify when and where a product was made. If you’re unsure what a code means...