The main constituents are essential oils (0.5–2.5%), cinnamic acid derivatives (rosmarinic acid), diterpenes (carnosol, carnosic acid, rosmanol, rosmadial), triterpenes (betulin, betulinic acid, ursolic and oleanolic acid), and flavonoids (glycosides of luteolin and diosmetin).
Used as a carminative and for relief of mild joint and muscle pain, including mild peripheral circulatory disorders. Also used for producing its essential oil (Rosmarini etheroleum), which is also pharmacopoeial.
The leaf is linear to narrowly lanceolate, up to about 4 cm long and 0.5 cm wide. It is sessile, rigid, and has rolled-under edges. The upper side is dark green and glabrous, with a granular texture, while the underside is gray-green and felted with a prominent midrib.
The drug is listed in the pharmacopoeia.
In pulverized drug under the microscope we can see:
Highly branched covering trichomes
Glandular trichomes typical of the Lamiaceae with a multicellular head
Simpler glandular trichomes with a unicellular head on a one- to two-celled stalk
Diacytic stomata
Wavy, corrugated walls of epidermal cells
Funnel-shaped hypodermis with rosary-like thickened cells
Single-layered epidermis covered by a very thick cuticle
Cells with straight, slightly thickened, and pitted walls
