Coix Lacryma-jobi Seed Water — INCI reference

What it is

Coix Lacryma-jobi Seed Water is the aqueous solution of the steam distillate obtained from the seeds of Coix lacryma-jobi (Job's tears), a cereal grass of the Poaceae family native to Southeast Asia. The distillate carries water-soluble constituents including amino acids, polysaccharides, B vitamins, vitamin E, and phenolic compounds such as ferulic and caffeic acids. These components work together to draw moisture into the upper layers of the skin, improve softness and flexibility, and provide mild antioxidant protection. The ingredient also contains coixol and phytosterols, which research has associated with inhibition of tyrosinase activity, supporting a more even skin tone. It is widely used in East Asian skincare—especially Japanese toners and essences marketed under the hatomugi (ハトムギ) designation—at low concentrations of 0.1–3%. The ingredient has a gentle profile and is considered suitable for most skin types, including sensitive skin.

Safety & warnings

Generally well tolerated; low sensitization and low irritancy profile reported across published studies. Ethanolic seed extract at 1 mg/mL showed no cytotoxicity to melanocytes in vitro. Rare individual allergic reactions are possible, as with any botanical ingredient. Avoid application to broken, injured, or acutely inflamed skin (eczema, dermatitis). Low comedogenicity. No known interactions with common cosmetic actives at typical use levels.

Origin & sourcing

Derived from the seeds of Coix lacryma-jobi var. ma-yuen, a cultivated annual grass grown primarily in East and Southeast Asia (Japan, China, Taiwan, Korea). The seeds are harvested and subjected to steam distillation; the resulting aqueous condensate is collected as the seed water. The plant has been cultivated as a cereal and used in traditional Chinese and Japanese medicine (Kampo: yokuinin / 薏苡仁) for at least two millennia.

History

Coix lacryma-jobi has been cultivated in India for roughly 3,000–4,000 years and in China for at least 2,000 years. Archaeological evidence from China (late Yangshao Culture, ~3000 BC) documents its use in fermented beverages. In Japan, phytolith records from ~4000 BC confirm early cultivation. The seeds' use in Kampo medicine under the designation yokuinin is well established; their incorporation into modern cosmetic formulations as a skin-conditioning and brightening ingredient reflects the broader J-beauty trend of botanicals with deep traditional roots.

Questions everyone asks

What does Coix Lacryma-jobi Seed Water do in skincare?

It acts primarily as a skin conditioner and humectant: the amino acids and polysaccharides it contains help attract and retain moisture in the outer skin layer, leaving skin feeling softer and more supple.

Is Job's Tears Seed Water the same as Job's Tears Seed Extract?

They are related but distinct INCI entries. The seed water is specifically the aqueous steam distillate from the seeds, while the seed extract may be obtained by solvent or water maceration and typically contains a broader range of constituents.

Is this ingredient safe for sensitive skin?

Published studies and cosmetic safety assessments rate it as low-irritancy and low-sensitizing, and it is commonly formulated in products targeting sensitive or reactive skin. Nonetheless, as with any botanical ingredient, patch testing is advisable for individuals with known plant-derived allergies

Why is this ingredient so popular in Japanese skincare?

In Japan, the plant is known as hatomugi (ハトムギ) and has a long history in folk beauty practices. Its association with bright, even skin tone and deep hydration is well established in traditional Japanese culture, and modern research on coixol's tyrosinase-inhibiting properties has reinforced its rep