[Stacy]

this was my original post on hennaforhair.com/forums:
<a href="http://www.hennaforhair.com/forum/index.php?module=phpwsbb&PHPWSBB_MAN_OP=view&PHPWS_MAN_ITEMS[]=6193&4e888c709e0d92276bae8ba6a347c0e5=8ea7c5bebcf9b5ea162fe3ef4f74f3a7">My original post</a>

In summary:
So everybody knows that "terping" (adding essential oils to the henna paste) can lead to darker, richer stains. Many sites that I've visited say to use essential oils that have "strong levels of terpenes". Most essential oils have high levels of terpenes, but apparently this relates to monoterpene alcohols and sesquiterpene alcohols specifically.

Is dye release relating to "terping" more related to monoterpene or sesquiterpene alcohol? If so, why?

et me break it down like this: Since henna is hydrophobic, it requires terpene alcohols to "help detach" the lawsone dye from the plant matter and become available. Terpene alcohols take the dye from "inside" the plant material and "coax" them to the "outside" of the plant material.

When you apply henna to your hair, you are applying your acidic mixture (acidic because of vinegar or lemon juice to create a pH of 5.5) to to an alkaline (best to wash hair with baking soda[pH 8.4] before henna-ing)surface. As the hair is alkaline, its cuticles open (this is why you get "frizzy" hair")and when you apply an acid, the cuticles shut. The henna mixture applied to hair "stuffs" the open cuticles with plant material, which includes the lawesone dye. The lawsone attaches to amino acids, keratin, and protien in the hair, creating a chemical bond which is dying your hair. The acid of the mixture "shuts" your hair cuticle, sealing in the attached colored molecules.

Different terpenes in essential oils are oxidative (meaning that they darken upon exposure to air), like citral, citronellal, citronellol, linalool, found in citrus. Eugenol (which is a phenol found in clove and cinnamon eo) is more oxidative than the previously mentioned terpenes. Some are gycosidal, like geraniol, a monoterpene alcohol, which helps bond amino acids (this is why sugars can be helpful in mixes).


According to Catherine, the Melaleuca genus provides the best stain. (Melaleuca is a genus of plants in the myrtle family Myrtaceae. It currently contains 236 species, all of which occur in Australia.) These all include moderate to high levels of terpineol (a monoterpene alcohol) and versions of.

Of these, cajeput has the highest level of terpinols, but pine, for example, has more than cajeput. Each of these oils have higher levels of terpinols than some other oils.

The people who were supposedly "experts" on the henna for hair site were not helpful at all. Dissapointingly unhelpful.

So can anyone provide an answer to which of the monoterpene alcohols will work best for henna?  I think I know, but I would like someone else to answer first.