Educational information, not medical advice — ask your doctor or midwife.
Manhyeongja is the dried fruit of beach vitex (Latin name: Vitex rotundifolia). In Korean herbal medicine it is used for headache, sore red eyes, and a heavy or dizzy head. It is also sold as Vitex fruit or beach vitex.
It is a single drug in the Korean system. That means it is one herb on its own, not a fixed mix of many herbs. Healers still often add it to a larger formula.
Here is the short verdict. The fruit has a long record of use across East Asia, but human trials are missing. A long history of use is not proof that a herb works, and that point is made once here for the whole page.
No one has shown how this fruit acts in the human body. What follows is an idea, not a proven path.
Korean and Chinese texts say it clears "wind-heat" from the head and eyes. In plain terms, that is the old model for a hot, throbbing head with red, watery eyes.
Lab and animal work points to two things. Some of its compounds calm swelling in cells, and some act on pain signals in mice. Cell and mouse results often fail to repeat in people, so treat this as an open question.
You will most often meet it as whole dried fruit, sold loose by weight. The fruit is simmered in water to make a tea, called a decoction.
It also comes as a ground powder and as a dry granule extract that you stir into hot water. Some shops sell capsules and tinctures (alcohol extracts).
In Korean clinics it is usually one part of a larger herb mix rather than a stand-alone product. Ask the seller for the Latin name on the label, since "vitex" is also used for a different plant, chaste tree.
Beach vitex grows on sandy shores in Korea, China and Japan. Its fruit has been listed in East Asian herb books for well over a thousand years.
Korean practice took it up from these shared classical texts and kept it in steady use. It is also used in Chinese medicine as man jing zi and in Japanese Kampo.
Its old job has stayed the same: head and eye complaints that feel hot and throbbing.
See a doctor rather than treating yourself if your headache is sudden and severe, if it comes with fever, a stiff neck, weakness or slurred speech, or if it is the worst you have ever had. Get urgent care for eye pain with loss of sight, or for dizziness with fainting or chest pain. Also see a doctor if your symptoms last more than two weeks, or if you get a rash, facial swelling or trouble breathing after taking it.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
One email with the summary. We'll also send a short weekly evidence update — unsubscribe any time.
