In many products isolates are used for enhanced effect. Isolates are the main molecular constituents in an essential oil, such as menthol in peppermint-oil, linalool in lavender, methyl salicylate in wintergreen or limonene in lemon. This means that the main constituent in an essential oil has been isolated and removed to be used on its own. The problem is that some of these isolates can be harmful to the body as the synergy is lost.
Synergy is when different parts together make up a whole. In most plant-matter there is a natural balance between activating and calming substances. For example essential oil of Clove Bud (Syzygium aromaticum): Its main molecular constituent is eugenol, up to 77%. It stimulates circulation and is anti-infectious. It is also a known skin-irritant in high doses. In proper dilution the whole essential oil is very useful for sore muscles, painful areas and as an anti-infectious agent. Clove oil is used in dentistry thanks to its anti-infectious and analgesic properties. The isolated eugenol is corrosive and toxic to the liver.
- Nutrition: Isolates are widely used as flavour-enhancers.
- Perfumes: They are mostly made up of synthetic aromas which are cheaper and more stable. Sometimes isolates are used. (eugenol in Kouros by Yves Saint Laurent)
- Sports-products: To warm and stimulate muscles before training and to cool and sooth aches and sprains. Most widely used isolates are menthol, camphene, methyl salicylate. It is not always clear if isolates or synthetics are used. Most of these isolates are strong skin-irritants in high doses – hence the warming / cooling effect on the skin. There have been a lot of discussion about the use of methyl salicylate, found in Wintergreen (Gaultheria procumbens) up to 98%. (Article)
- Skin-care: Isolates are used as perfuming-agents in many skin-care products. Sometimes, especially in natural or bioproducts, both essential oils and isolates are used. Isolates are much cheaper to use than essential oils. Here is a list of perfume-agents in a hand-cream: Citral, citronellol, eugenol, farnesol, geraniol, limonene, linalool. All of these are noted to come from certified organic growers and from natural essential oils… (Check out earlier posts on natural & organic skin-care)
What is definite is that there is no way of knowing if the aromatic ingredients in a product are from natural sources (unless stated) or if they are produced synthetically…which means that there is no way to know if they will be harmful or not.