Foods high in vitamin C such as parsley, ginger and dong quai have been known to induce periods early or starting delayed periods. Parsley tea and cranberry juice are convenient methods of increasing vitamin C intake, but supplements made of pure ascorbic acid and devoid of flavonoids are also recommended.
Vitamin C is thought to start periods because it increases estrogen levels in women, reducing the production of progesterone and causing the uterus to contract so that menstruation begins. Very little true scientific research has been done on the effect of vitamin C on the menstruation cycle however, though two medical students on Science-Based Medicine have researched the myth that vitamin C can induce early abortion and reported inconclusive findings.
Dong quai, also known as Chinese Angelica or female ginseng, has been used in traditional Chinese medicine for over 2000 years not only to start periods and induce abortions but also to alleviate cramping and maintain normal reproductive function. If irregular periods are a problem, try eating grapes, papayas and aloe vera juice to regularize the menstrual cycle.
In order to start the period early, it claims that drinking sugarcane juice one to two weeks before the expected date is a common method.