Rosemary

Salvia rosmarinus

Family: Lamiaceae Part used: Leaves and stems

Key Compounds

• Carnosic acid
• Rosmarinic acid
• 1,8-Cineole
• α-Pinene
• Camphor
• Carnosol
• Ursolic acid

Traditional Use

• Ancient Egyptian burial rites — rosemary branches found in pharaonic tombs
• Ancient Greek study aid — students wore rosemary garlands during examinations
• Medieval European herbalism — Hildegard von Bingen's 12th-century writings
• Hungary Water (c.1370) — the first named perfume in European history, rosemary-based
• Modern food industry — carnosic acid (E392) used as a natural antioxidant in packaged foods

Ancient Greek students wore rosemary garlands during examinations. This is documented.

Queen Isabella of Hungary had it distilled into what became the first named perfume in European history. Also documented.

It is now in your packaged food as a natural antioxidant. The label says “rosemary extract” or “E392.” Most people don’t make the connection. The plant is not concerned.

Meet the plant

A woody evergreen shrub from the Mediterranean coast, 1–2 metres tall, with needle-like aromatic leaves: dark green on top, white and woolly underneath. The leaves release a resinous, camphor-like fragrance when touched — stronger than most herbs by some distance. Flowers are small, pale blue-violet, in clusters along the stems, mainly spring and early summer.

The name is literal: ros marinus — “dew of the sea.” Rosemary grows naturally on coastal cliffs and rocky scrubland where sea mist provides moisture in an otherwise dry environment. The habitat, the name, and the plant are all consistent. It knows what kind of country it belongs in.

2,000 years of memory, perfume, and preservation

The association between rosemary and memory predates any chemistry explaining why. Greek students wore it during exams. Roman brides carried it. Ophelia mentions it by name in Hamlet. The symbolism held across cultures and centuries without updating its source material.

Around 1370, a preparation called Hungary Water was made for Queen Isabella of Hungary — rosemary flowers distilled in alcohol. This was a named, reproducible formula for a scented liquid. Hungary Water is considered the first named perfume in European history. It influenced Eau de Cologne (which also contained rosemary). Which influenced modern perfumery. The whole lineage starts with rosemary on a cliff face above the Mediterranean.

The industrial chapter came later. Chemists identified carnosic acid as rosemary’s primary antioxidant compound. It prevents oils and fats from oxidising and going rancid — the same job as synthetic preservatives BHA and BHT. When food manufacturers began seeking “natural” label options, rosemary extract became E392 in the EU. Today it is a significant commercial ingredient in packaged foods, cooking oils, processed meats, and animal feed. Most people eating food labelled “contains rosemary extract” are unaware they are consuming industrial antioxidant chemistry. The plant has a second career they don’t know about.

The chemistry

Three compounds doing three different jobs. At least one of them is in your lunch right now.

Carnosic acid is the food industry compound. Such a powerful antioxidant that it gets extracted from rosemary and sold commercially as E392 — added to cooking oils, packaged nuts, and processed meats to prevent oxidation. The herb in your kitchen and the preservative in your supermarket crackers are the same plant, doing the same chemistry, in different contexts. You won’t taste it in the crackers. It quietly converts to carnosol when oxidised, and both forms keep working. Most people have no idea this is happening. The plant has no comment.

1,8-Cineole makes up to 50% of the essential oil — and it is the same compound that dominates eucalyptus. This is why good rosemary oil has that slightly medicinal edge. The memory studies all focused on this compound. Whether smelling rosemary actually helps you remember things is still an open question with a 2,500-year head start.

Rosmarinic acid was named after rosemary. This sounds like rosemary’s compound. It is found in practically every plant in the mint family. The naming happened before anyone checked. They did not check.

What people actually do with it

In the kitchen: roasted meat, potatoes, flatbread. Lamb and rosemary is a combination so obvious that multiple ancient cultures arrived at it independently, which suggests it is correct. One sprig of fresh rosemary is enough for most dishes. Two is usually too much. This is worth remembering.

Practical trick: strip the leaves off a sturdy rosemary stem and use the bare stem as a skewer for grilling. The wood flavours the meat from the inside. This has been done for a long time. There is a reason.

In food manufacturing: same plant, different context. Rosemary extract (carnosic acid, E392) in cooking oils, packaged nuts, and processed meats to prevent rancidity. “Contains rosemary extract” on a label means industrial chemistry, not flavour. Worth knowing when reading labels.

In hair care: a 2023 randomised controlled trial compared rosemary oil to 2% minoxidil for hair density and found similar results at six months. One study is not a definitive answer. But it is a real clinical trial with a real positive result, and the Japanese hair care market responded almost immediately.

As a tea: dried rosemary, hot water, five minutes. Resinous, slightly camphor-like, warming. The simplicity is the point.

Could you grow this yourself?

Yes — rosemary is one of the easiest herbs to grow in most of Japan. It wants sun, well-drained soil, and infrequent watering. It actively dislikes waterlogged roots. In Japan’s climate, the main threat is overwatering, not cold.

Plant in spring or early autumn in full sun. Sandy or gritty soil preferred. Water infrequently once established. Do not let it sit in wet soil over winter. Harvest by snipping the newest growth; never cut more than one-third at a time. Rosemary does not reliably regenerate from old woody stems. It has views about this.

In Kyushu and southern Honshu: grows freely, can become a large shrub. Kanto and central Japan: thrives. Tohoku: shelter from the coldest winds. Hokkaido: container plant, overwinter indoors or in a cold frame.

Rosemary (ローズマリー) in Japan

Two distinct identities in contemporary Japan, not closely connected in most Japanese consumers’ minds.

The first: an everyday culinary herb — sold fresh in supermarket herb sections, used in Italian-style cooking. Standard pantry herb for pasta, roast chicken, flatbreads.

The second: hair care. In 2023, the randomised controlled trial comparing rosemary oil to minoxidil spread rapidly through Japanese social media. Instagram, TikTok, YouTube, beauty publications. Rosemary scalp serums, shampoos, and hair oils appeared in drugstores. DIY preparations became a home beauty trend. This happened fast.

As a garden plant, rosemary is among the most popular herbs for Japanese balcony growing — evergreen, low-maintenance, visually coherent with the Mediterranean herb garden aesthetic that Japanese lifestyle media promotes alongside olive trees and lavender.

The historical identity — the Greek exam garland, the first European perfume, the Roman wedding herb — is largely unknown in Japan. What is known is the culinary herb, the hair treatment, and the garden shrub. Two thousand years of documented use, and Japan’s version is six years old.

Things you’re probably wondering

Is rosemary actually good for memory? The claim is 2,500 years old — ancient Greek students wore rosemary garlands during exams. The compound 1,8-cineole (from rosemary’s aroma) has shown effects on cognitive performance in some studies, providing some biological plausibility. But the human evidence is limited and inconsistent. The association between rosemary and memory is genuine ancient tradition; whether it works as a brain enhancer is still an open question.

What is Hungary Water? Hungary Water, made around 1370 for Queen Isabella of Hungary, is considered the first named perfume in European history — a prepared scented liquid with a recorded name and recipe, rather than just scented oil. It was rosemary flowers distilled in alcohol. It influenced the later development of Eau de Cologne (which also contained rosemary). Several modern perfumers recreate it as a historical curiosity.

Why does rosemary appear on food labels as an additive? Carnosic acid — the main antioxidant compound in rosemary — is approved as food additive E392 in the EU. It prevents oils and fats from oxidising and going rancid, which is the same job that synthetic antioxidants BHA and BHT do. When consumers pushed for ’natural’ ingredients on labels, manufacturers switched to rosemary extract. You’re eating chemistry extracted from rosemary, not actually tasting the herb.

Is rosemary the same plant as sage now? Botanically, yes — since 2017, rosemary is classified as Salvia rosmarinus, making it a sage. Before that it was Rosmarinus officinalis in its own genus. Molecular phylogenetic analysis showed that the old Rosmarinus genus sits inside the Salvia genus, so taxonomists merged them. In practical terms — in the kitchen, the garden, and in commerce — nothing has changed. The old name is still everywhere.

Does rosemary actually work for hair growth? A 2023 randomised controlled trial compared rosemary oil to 2% minoxidil (a standard pharmaceutical treatment) and found similar increases in hair density at six months. That single study is not enough to make a definitive claim — but it’s a real clinical trial with a positive result, not just folklore. The Japanese hair care market responded quickly; rosemary-based hair products became strongly trending from 2023 onward.

Where can I find rosemary in Japan? Fresh rosemary is in most Japanese supermarkets year-round in the fresh herb section. Dried rosemary is in spice sections everywhere. Rosemary shampoos, scalp serums, and hair oils are widely available in drugstores (Matsumoto Kiyoshi and similar) and online, driven by the 2023 hair growth study trend. Rosemary plants are sold in garden centres and home improvement stores — it is one of the most popular herbs for Japanese balcony and garden growing.

Botanical details

The full compound list

See Also

• Lavender — same family (Lamiaceae); Mediterranean herb with similarly strong fragrance and extensive European history
• Sage — now in the same genus (Salvia); shares carnosic acid as primary antioxidant
• Thyme — Lamiaceae family; classic culinary companion to rosemary

References

• Andrade, J.M. et al. (2018). Rosmarinus officinalis L.: an update review of its phytochemistry and biological activity. Future Science OA, 4(4).
• Panahi, Y. et al. (2015). Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed, 13(1), 15–21.
• Mabberley, D.J. (2017). Mabberley’s Plant-Book. Cambridge University Press.
• Morales, M. (1997). The History, Botany and Taxonomy of the Genus Thymus. In: Stahl-Biskup, E. & Sáez, F. (Eds.), Thyme. Taylor & Francis.
• European Food Safety Authority (2015). Scientific Opinion on the re-evaluation of rosemary extracts (E 392) as a food additive. EFSA Journal, 13(5).