Geranial is one of the primary chemical components of lemon balm (Melissa officinalis). It is one of the many volatile oils that give lemon balm its delightful scent. Geranial has a smell that reminds the herbalist of lemongrass. Geranial is one of the citral molecules that is credited as having a spasmolytic effect.
Spasmolytic herbs effect the smooth muscle system. These are also called involuntary muscles which control muscles of the major systems such as the digestive and circulatory system. Even the contraction of the iris can be effected by spasmolytic herbs. The broad spectrum of effects from volatile oils like geranial explains why lemon balm is useful in the treatment of so many conditions.
The combination of smooth muscle related effects makes lemon balm a great treatment for anxiety and digestion related disorders. It is a common herb to add to formulas for soothing patients with sleep disorders as well. As the smooth muscle effect makes lemon balm a moderate nervine, it should not be coupled with CNS depressants but works well when balanced with other nervines such as St. John’s wort, milky oats, chamomile and motherwort.
Not all lemon balm is created equal. Lemon balm is one of those herbs that is preferred to use fresh. The difference in syrup made from fresh lemon balm and dry lemon balm is significant. The volatile oils in the leaves dissipate after time. One study showed that geranial in leaves from 2 year old lemon balm plant is higher than the geranial amount from a younger, 1 year old lemon balm plant. It is possible that geranial needs the thicker leaf structure of a tougher, older plant in order to preserve the volatile oils.
Extracting geranial in dry lemon balm leaves effectively is more complicated than fresh leaf extraction. It is important to test the quality of the leaves that you use. As with any volatile oil, the organileptic method is a quick, first test that can be done anywhere. Crush a dried leaf between your fingers and smell it carefully for the lemongrass scent. Lemon balm also has citronellal volatile oil which smells like lemon. The fragrances are similar. The chemical difference between them is that citronellal has more hydrogen. Citronellal is used as a mosquito repellant and an antifungal agent. Both have a shelf life of 2 years if the product is stored away from light and in a properly sealed container.
Lemon balm is counterindicated for hypothyroidism. The geranial and the citronellal has not shown on tests to be problematic for the thyroid. Thus far, lemon balm’s trierpene acid Romaric acid seems to be the culprit. Do not use lemon balm if you have a thyroid disorder.