Menthol

Menthol, “Kled SaraNae” in Thai (เกล็ดสะระแหน่) is a natural compound, essential in traditional Thai medicine.

It is extracted from mint leaves in the form of crystals.

It has analgesic, anti-inflammatory, and refreshing properties. It is particularly effective in relieving muscle pain, headaches, skin conditions, insect bites, and respiratory disorders.

Mint from the provinces of Chiang Mai, Nakhon Pathom, and Ratchaburi is of the highest quality, very rich in menthol and aroma.

Benefits and Uses

Menthol is the main active compound in mint crystals, which provides them with their numerous health and well-being benefits.

Analgesic

Helps to relieve muscle, tendon and joint pain, in particular by improving blood circulation in the affected area. Helps relieve headaches and migraines

Anti-inflammatory

Helps to reduce body inflammation, swelling and stiffness. Relieves muscle, joint and ligament pain. Helps to reduce the symptoms of certain inflammatory conditions such as arthritis, rheumatism, sprains, but also asthma and bronchitis.

Vasodilator

Participates in improving blood circulation and therefore in the supply of oxygen and nutrients to the tissues. It thus helps to relieve muscle pain, heavy leg syndrome, edema, varicose veins.

Decongestant and expectorant

Helps relieve nasal congestion and clear upper respiratory tracts, such as sinuses, throat, and bronchi. Facilitates the evacuation of mucus and thus the breathing during allergies, coughs, colds, sinusitis.

refreshing

Provides a feeling of freshness and soothing when applied to the skin. Used in particular to soothe sunburns and light burns.

sedative

Intervenes in the regulation of levels of cortisol, the stress hormone. It thus has a calming effect on the mind and helps to reduce stress and anxiety.

Historical Origins

The use of menthol in traditional medicine dates back several centuries. Its origin can be traced back to different cultures around the world:

Traditional Thai Medicine:
Menthol has been used there at least since ancient times for its pain-relieving, anti-inflammatory, refreshing, and soothing effects in the treatment of muscle pain, tension, and headaches. The first written mentions of its use date from the Sukhothai period (13th-14th centuries) but the oral transmission of his knowledge dates back to much earlier periods.

Menthol is also mentioned in the “Tamra Phra Songkhrut” ("ตำราพระสงฆ์รุตต์"): It is one of the oldest and most important medical manuscripts of traditional Thai medicine. It was compiled during the Ayutthaya period (14th-18th centuries) and deals with various aspects of medicine, including physiology, diagnostics, and treatments.

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Traditional Chinese Medicine:
Menthol is mentioned there in ancient medical texts such as the “Shennong Ben Cao Jing” dating from the time of the Han dynasty (206 BC). J.-C. - 220 AD J.-C.).

Ayurvedic medicine:
Menthol is considered refreshing, soothing and stimulating.

European Traditional Medicine:
In Europe, menthol has been used in traditional medicine for its pain-relieving, antispasmodic, and refreshing properties.

Today, menthol continues to be used in various medical traditions around the world, as well as in the pharmaceutical industry and health and wellness products

SOURCES

Menthol is an organic compound that is often extracted from various species of plants in the mint family (La miaceae). In Thailand, menthol is mainly extracted from two mint species that are commonly grown commercially:

  • Mentha arvensis: Also known as field mint, this species of mint is one of the most common sources of menthol in the world because it is rich in menthol.
  • Mentha haplocalyx: also called Chinese mint, this mint species is native to China, but it is also fairly commonly grown in Thailand.

In addition to these two mint species, other mint species are also found in Thailand, such as Mentha piperita (peppermint), an important source of menthol worldwide.

 

Mint is grown in different regions of Thailand and there is no consensus on a specific region that would produce the “best” mint. At Sayam, we particularly appreciate three regions known for producing high quality mint:

  • Chiang Mai: Located in northern Thailand, the province of Chiang Mai has climatic conditions and fertile soils that favor the growth of mint rich in menthol.
  • Ratchaburi: Located about 200 km southwest of Bangkok, local farmers grow different varieties of mint here, including spearmint and peppermint.
  • Nakhon Pathom: Also located not far from Bangkok, the province of Nakhon Pathom is home to major mint farms for the production of essential oils.

These regions are considered to be suitable areas for growing mint because of their climatic conditions and their adapted soils, but also because many producers practice agriculture that respects traditional methods.

PRODUCTION

Menthol crystals are produced from mint essential oil using the following manufacturing process:

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  • Harvest: Mint leaves are harvested, usually early in the morning, when the essential oil content is higher. They are picked by hand in order to preserve their quality and freshness.
  • Distillation: They are placed in a traditional copper still with water. The steam passes through the leaves, taking the essential oil with it.
  • Crystallization: The distillate is then cooled and stirred to promote the separation of the oil. Crystallization occurs when the essential oil cools and solidifies, forming menthol crystals.
  • Filtration and drying: The menthol crystals are separated by filtration. The crystals are then washed to remove impurities and dried to remove residual moisture.
  • Packaging: The menthol crystals are then packaged in moisture-proof containers to be then distributed.

COMPOSITION

Mint crystals are composed primarily of menthol, which is a naturally occurring organic compound. However, in addition to menthol, mint crystals may contain other compounds such as:

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  • Menthone: It is another major compound in mint essential oil that contributes to the aroma of mint and also has refreshing properties.
  • Isomenthone: Menthone isomer
  • Isomenthol: Menthol isomer present in small quantities in mint crystals.
  • Menthofuran: Aromatic compound found in limited quantities in mint crystals.

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Pure mint crystals generally contain a high concentration of menthol, which can exceed 99% of the total composition.