Coix (Coix lacryma-jobi)
Synopsis of coix
Coix (Coix lacryma-jobi), also known as Job’s tears, Chinese pearl barley, or yi yi ren in Traditional Chinese Medicine (TCM), is a cereal grain native to Southeast Asia and parts of China and India. Though it resembles barley, coix belongs to the grass family Poaceae and is more closely related to maize than to true barley. The edible seeds of the plant are rich in complex carbohydrates, protein, essential fatty acids, and bioactive compounds, including coixenolide, coixol, sterols, and polysaccharides.
Medicinally, coix is prized for its diuretic, anti-inflammatory, antitumor, and immunomodulating properties. It is commonly used to drain dampness, promote urinary flow, reduce swelling, and support digestion, especially in cases of edema, arthritis, and digestive sluggishness. In modern studies, coix seed extracts have demonstrated potential in supporting metabolic health, inhibiting tumor growth, enhancing immune function, and reducing insulin resistance.
Coix is especially valued in TCM for clearing damp-heat conditions—patterns associated with symptoms like bloating, joint stiffness, pus-forming skin issues (such as acne or abscesses), and loose stools. It is also included in herbal formulas for chronic lung congestion, reproductive inflammation, and intestinal disorders.
Coix seeds are consumed as food (often in porridges or soups), as teas, or as part of standardized herbal extracts or granules. They are generally well tolerated, though some formulas advise caution in pregnancy, as the herb is traditionally thought to stimulate uterine contractions in high doses.
Historical Use
Coix has a long-standing presence in Chinese, Korean, and Japanese traditional medicine, where it is categorized as both a medicinal herb and a food-grade tonic. In Traditional Chinese Medicine, yi yi ren is classified as sweet and bland in flavor and slightly cooling in nature. It enters the spleen, lung, stomach, and kidney meridians, and is primarily used to eliminate dampness, strengthen the spleen, and expel pus from internal abscesses.
Ancient texts such as the Shennong Bencao Jing documented its use for conditions like arthritis, diarrhea, respiratory congestion, and skin ulcers. It was also used as a general tonic for weakness and convalescence, particularly for individuals with chronic damp conditions or digestive deficiencies. In Korea and Japan, coix was traditionally used for rheumatism, warts, and skin blemishes, and was prepared in both food and tea forms.
Coix seeds were also used in ritual contexts and jewelry-making—hence the name “Job’s tears,” due to the bead-like appearance of the hard outer shell of certain wild varieties.
Today, coix remains a staple of Asian herbal and dietary therapies, widely available in grains, capsules, teas, and decoctions. It is often incorporated into detox, weight management, and anti-inflammatory protocols, and is praised for its dual role as a nutritive food and gentle medicinal agent.
Coix is used for these health conditions
Cancer (natural therapy for) (Scientific)
Cancer (prevention) (Scientific)
Cancer Treatment (reducing side effects) (Scientific)
Chemotherapy (reducing side effects) (Scientific)
Diabetes (Scientific)
Fatty Liver Disease (Scientific)
Gastritis (Traditional)
Hypertension (Traditional)
Inflammation (Scientific)
Liver Detoxification (Traditional)
Nephritis (Traditional)
Urinary Tract Infections (Traditional)
coix is used to support these body systems
Bladder (Traditional)
Blood (Traditional)
Digestive System (Traditional)
Gastrointestinal Tract (Traditional)
Immune System (Traditional)
Intestinal System (Traditional)
Joints (Scientific)
Kidneys (Traditional)
Large Intestines (Colon) (Traditional)
Liver (Traditional)
Lungs (Traditional)
Skin (Scientific)
Spleen (Traditional)
Stomach (Traditional)
Urinary System (Traditional)
Products containing coix
Nature's Sunshine Kidney Activator TCM
Nature's Sunshine Kidney Activator (Chinese)
