Duchess belongs to a kind of Chinese herbal medicine, which has a shelf-life, the conventional shelf-life limit is 3~5 years, but the shelf-life of Chinese herbal medicine is variable and affected by the preservation environment. Cortex Eucommiae is the dried bark of Cortex Eucommiae, a plant of the family Eucommiaceae. It has good effects of tonifying the liver and kidney, strengthening the tendons and bones, and tranquilizing the fetus, and can be used clinically for treating deficiency of the liver and kidneys (weakness of the liver and kidneys), lumbar and knee pains, weakness of the tendons and bones, dizziness, leakage of blood in pregnancy, and restlessness of the fetus, among other conditions. Cortex Eucommia Ulmoides has a shelf life. During daily storage, attention should be paid to moisture-proof and pest prevention. Once Cortex Eucommia Ulmoides is found to be moldy on the surface or with obvious insect infestation, all of them are regarded as having lost their medicinal value and belonging to the expired medicines; under the regular preservation conditions, Cortex Eucommia Ulmoides has a shelf life of about 3~5 years in general. Cortex Eucommia should be used properly under the guidance of professional physicians, and its adverse reactions and contraindications are not clear.