The centre of diversity of lemon is South-Eastern Asia but it is cultivated nearly everywhere in tropical and subtropical areas. The United States and Italy are two of the leading producers. Its fruit is a modified berry (hesperidium) with a fleshy interior with separate sections, developed from five or more carpels. The rind consists of three layers: the outmost is the thin, leathery exocarp or epicarp, below which there is the mesocarp consisting of two layers, the yellow, tough flavedo, containing essential oil and the innermost, spongy, white albedo (pith). The fleshy interior consists of membranous diaphragms and fluid-filled vesicles (specialised hair cells) with white seeds, which contain several embryos. Some cultivars have no seeds. In the great period of European naval exploration the lemon proved to have antiscorbutic properties due to its high Vitamin C content, and as a result, the serious and often deadly disease was kept at bay among sailors travelling for months or years. In addition to its health benefits, lemon is also an important culinary raw material: its aromatic, slightly bitter rind (zest) and sour juice are used for making various dishes and drinks.

The juice is to be consumed to prevent Vitamin C deficiency, while its essential oil has antiseptic, disinfectant and refreshing effects if evaporated.

Lemon juice has bleaching, regenerating, moisturising and toning effects in cosmetic masks and other products and thus refreshes and rejuvenates the skin making it resilient again. It is highly recommended for oily, seborrhoeal skin affected by acne. Its essential oil is used by the beauty industry for its pleasant, fresh fragrance and its fruit, rind and juice are used as a roborant.

Rind (Citri pericarpium):
- Essential oil (citral)
- Flavonons (neo-hesperidin)

Seed:
- triterpene bitter principles (limonin),

Pulp:
- Sugars: 8-9%,
- Citric acid 1 %,
- Vitamin C: 50 mg/100g