Herb reference
Perilla frutescens
Crystalis is a reference resource for herbal, crystal, and somatic practice.
This library is designed to help readers orient, compare, and research. It is not a substitute for medical care or practitioner judgment.
Botanical / meta
An aromatic annual herb growing 60–90 cm tall with distinctly four-angled (square) stems characteristic of the mint family. Leaves are broadly ovate with toothed margins, deeply colored in green (aojiso) or red-purple (akajiso) varieties. Small, bell-shaped white or pale purple flowers appear in slender terminal spikes in late summer. The entire plant has a complex aroma — notes of cinnamon, clove, mint, and cumin — due to its unique volatile oil composition.
Shiso leaves contain a distinctive volatile oil rich in perillaldehyde (the primary odorant), limonene, myristicin, elemicin, and anthocyanins (in purple varieties). The seeds yield perilla seed oil, one of the richest plant sources of alpha-linolenic acid (ALA, omega-3, up to 60% of total fatty acids). Also contains flavonoids including apigenin and luteolin glycosides; rosmarinic acid; caffeic acid; and triterpenoids. The rosmarinic acid content contributes to significant antioxidant and anti-inflammatory properties.
The practical read
Shiso leaves contain a distinctive volatile oil rich in perillaldehyde (the primary odorant), limonene, myristicin, elemicin, and anthocyanins (in purple varieties). The seeds yield perilla seed oil, one of the richest plant sources of alpha-linolenic acid (ALA, omega-3, up to 60% of total fatty acids). Also contains flavonoids including apigenin and luteolin glycosides; rosmarinic acid; caffeic acid; and triterpenoids. The rosmarinic acid content contributes to significant antioxidant and anti-inflammatory properties.
Route panel
Evidence and safety may differ by preparation. Essential oil, tea, tincture, extract, infused oil, and topical use are not interchangeable.
Quality
Warm-season annual; direct sow outdoors after all danger of frost, 30 cm apart in full sun. Prefers rich, well-drained, consistently moist soil. Pinch growing tips to encourage bushy growth and prevent premature flowering. Harvest outer leaves continually. Self-seeds prolifically; volunteers readily appear the following spring. Protect from strong winds — stems are brittle.
Fresh leaves are preferred for culinary use — available at Asian grocery stores. Purple shiso (akajiso) is sharper and more astringent; green shiso (aojiso) is milder and more aromatic. Perilla seed oil should be cold-pressed, kept refrigerated, and used within 3 months of opening. Dried leaves lose significant volatile oil content. Quality markers for fresh leaves: vibrant color, crisp texture, strong aromatic scent without browning or wilting.
Companion
Crystal side
The deeper layer
Clinical and compound notes are included as a research layer, not as treatment instructions.
Shiso leaf is generally recognized as safe in food quantities. Perilla seed oil is highly unsaturated and oxidizes rapidly — must be kept refrigerated and consumed promptly; rancid oil may produce harmful lipid peroxides. The essential oil contains perillaldehyde and perilla ketone — the latter has been associated with pulmonary toxicity in grazing animals (cattle, horses) consuming large quantities of the plant; human toxicity at normal dietary levels has not been reported. High rosmarinic acid content may theoretically interact with anticoagulant medications, though clinical evidence is limited. Pregnancy: safe in food quantities; avoid concentrated essential oil and large medicinal doses of extracts due to insufficient safety data. Contains trace amounts of myristicin — not a concern at dietary levels.
Questions
Shiso leaf is generally recognized as safe in food quantities and has a long culinary record in Japanese and Korean cooking. The essential oil contains perilla ketone, which has caused pulmonary toxicity in grazing cattle and horses consuming large quantities, though no human toxicity has been reported at dietary levels. The high rosmarinic acid content may theoretically potentiate anticoagulants such as warfarin, so consistent intake is wise for patients on blood thinners. Perilla seed oil is among the richest plant sources of alpha-linolenic acid (ALA, up to 60% of total fatty acids) and oxidizes rapidly, meaning rancid oil can yield harmful lipid peroxides. In pregnancy, food amounts are safe but the concentrated essential oil and large extract doses should be avoided due to insufficient data.
Fresh leaves are used whole or chiffonade-cut as a garnish, wrap, or pickling agent, and are best added late so the volatile perillaldehyde aroma is not driven off by heat. Purple (red) shiso is traditionally salted and pressed to color and flavor umeboshi plums and shiso vinegar, while green shiso is favored raw with sashimi and tempura. For rosmarinic acid extraction in allergy-focused preparations, the leaf is steeped as a strong infusion; one human trial (Takano et al., 2004) used a rosmarinic-acid-enriched extract for seasonal allergic rhinoconjunctivitis. Perilla seed oil should be used unheated as a finishing oil to preserve its ALA. Keep culinary use to food quantities and avoid concentrated essential oil internally.
Fresh leaves should be crisp and aromatic with an intense, clean perillaldehyde scent that carries cumin and cinnamon notes; faint aroma signals depleted volatile oil. Green shiso should be vivid and unblemished, and red shiso a deep, even purple-red from its anthocyanin content rather than dull or browning at the edges. Reject leaves that are wilted, slimy, or yellowing, as these have lost both flavor and the rosmarinic acid that gives the herb its antioxidant value. The serrated leaf margin should be distinct and the surface free of pest damage. For seed oil, choose refrigerated, dark-bottled product with a recent press date, since rancidity from ALA oxidation is the main quality failure.
Although shiso (Perilla frutescens) shares the mint family with basil and true mint, its signature odorant is perillaldehyde rather than the linalool and methyl chavicol of sweet basil or the menthol of mint, giving it a unique cumin-cinnamon-anise character. Unlike most Lamiaceae culinary herbs, shiso doubles as an oilseed crop, with its seed delivering one of the highest plant ALA concentrations known. The purple cultivars carry substantial anthocyanins absent from green basils, which is why red shiso is used as a natural colorant. Its rosmarinic acid content is high even among a family already rich in that polyphenol, underpinning the allergy research. This combination of leaf herb, colorant, and omega-3 oilseed is distinctive within the family.
Fresh leaves are delicate and best used within a few days; wrap them in a slightly damp paper towel in a sealed container in the refrigerator, and avoid bruising, which accelerates aroma loss. They do not dry well for culinary use because the volatile perillaldehyde dissipates and the leaf loses its defining character, so freezing whole leaves or making a salt-pressed or vinegar preparation preserves flavor better than air-drying. Salted red shiso keeps for months and is the traditional way to hold the harvest. Perilla seed oil is the most perishable form and must be refrigerated, kept in dark glass, and used promptly, since its high ALA content makes it prone to rapid oxidation and rancidity. Discard any seed oil with a paint-like or bitter off-smell.
Sources & Citations
Peer-reviewed sources for the pharmacological and clinical claims on this page. Crystalis herb entries describe tradition and current research; they are reference, not medical advice.
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Resource framing
Crystalis is a reference resource for herbal, crystal, and somatic practice.
This library is designed to help readers orient, compare, and research. It is not a substitute for medical care or practitioner judgment.
Clinical and compound notes are included as a research layer, not as treatment instructions.
Evidence and safety may differ by preparation. Essential oil, tea, tincture, extract, infused oil, and topical use are not interchangeable.