How does Melissa CO2 extract compare with the essential oil? With the increased availability of CO2 extracts on the market, it is always interesting to compare their similarities and differences.  Today I compare Melissa CO2 extract and Melissa Essential Oil.  In spite of being highly aromatic, Melissa does not yield much in the way of aromatic extracts.  You can read a little more in the article on Melissa.

Common to both

Name: Melissa (Lemon balm) (Melissa officinalis)

Family:   Lamiaceae (Labiatae)

Description:  A sweet-scented, highly aromatic herb with bright green serrated leaves, square stems, and tiny white or pink flowers.

History/Folklore: Melissa (Lemon balm) is a medicinal herb that has been known for a long, long time. Paracelsus, a 16th-century physician, and alchemist referred to Melissa as the “Elixir of Life”.  It was particularly associated with nervous disorders, the heart, and emotions.  In ancient folklore, Melissa was a plant which symbolized sympathy and was used to transmit messages between lovers. Melissa was the main ingredient of Carmelite Water, which was created by the nuns of the Abbey of St Just in the 14th century and commercialized under the name Eau de Carmes.

Differences

Method of Extraction

CO2: Carbon dioxide as the `solvent` to extract the viscous liquid from the dried leaves. YieldCO2 Select extract: 1Kg/300 Kg of dried plant material.  Yield Total extract: 1Kg/80Kg dried herb.  (Kerkhof)
Essential Oil:  Melissa essential oil is obtained through steam distillation of the leaves and flowering tops.  Although a highly aromatic plant, Melissa yields very little essential oil.  This makes Melissa an expensive oil.  It also makes Melissa an oil that is often adulterated.   Yield: 0.01% is typical. (Burfield)

Colour and Appearance

CO2:   CO2 Select extract: Clear to a red to orange-amber colour.  CO2 Total extract:  Greenish brown, turbid and paste like extract. (Kerkhof)
Essential Oil:
 Pale yellow oil.  (Burfield)

Aroma

CO2:   CO2 Select extract: soft, light with a hint of lemon, but earthy.  CO2 Total extract: smooth, pleasant smelling extract with a hint of lemon.  (Kerkhof)
Essential Oil:
  The steam distilled oil is lemon-like with a strong methyl heptenone bitter grassy note, which after a few minutes becomes more pleasant and lemongrass like.  (Burfield)

Chemistry

CO2:  CO2 Select extract includes waxes, fatty acids and up to 90% essential oil which contains around 65% citral, beta-caryophyllene around 13%, citronellal around 3%, caryophyllene oxide,  geranyl acetate, and geraniol. CO2 Total extract includes resins, waxes, fatty acids and up to 10% essential oil which contains around 55% citral, 12% beta-caryophyllene,8% caryophyllene oxide, geranyl acetate, geraniol, citronellal, and spores citronellol and 1,8-cineole. (Kerkhof)

Essential Oil:   Aliphatic aldehydes (50%) mainly citral; Sesquiterpenes (20%); Alcohols (5%); Oxides (4%); Monoterpenes (1%).

Cautions

CO2:  CO2 Select extract: can cause sensitization due to high citral content.   CO2 Total extract: risk of sensitization is lower than with the distilled oil or the CO2-select extract. (Kerkhof)
Essential Oil:
Hazards: Skin Sensitization.  Cautions (dermal): hypersensitive, diseased or damaged skin, children under 2 years of age. (Tisserand and Young)

Indications for Use

CO2:  Immune stimulant, headaches, migraine, herpes infections, insect bites and stings, skin inflammations and infections, varicose veins, menstrual cramps. (Kerkhof)
Essential Oil:
 Allergies, insect bites, asthma, bronchitis, chronic coughs, colic, indigestion, nausea, menstrual problems. (Lawless)

Emotional and Spiritual Conditions

Because both emotional and spiritual conditions can be influenced mainly through aroma, both the CO2 extract and the essential oil are effective.  They are used for emotional and spiritual conditions like anxiety, depression, grief, despair, and shock.  They can be helpful in calming agitation (in ADHD) and for dementia.  Madeline Kerkhof reports that she has seen Melissa CO2 Select extract, which she prefers to CO2 Total extract for emotional and spiritual wellbeing,  work very well in supporting the very sick and dying, bringing acceptance, tolerance, and understanding.

References
Tony Burfield, Natural Aromatic Materials – Odours & Origins, 2000E. 
Joy Bowles, the A to Z of Essential Oils, 2003
Madeline Kerkhof, CO2 Extracts in Aromatherapy, 2018
Julia Lawless, The Complete Aromatherapy & Essential Oils Sourcebook, 2017
Tisserand and Young, 2nd Edition Essential Oil Safety, 2014