INCI: Origanum vulgare
Oregano is becoming a popular additive to hair products because of its very strong antibacterial properties. It is extracted from the leaves of the wild oregano plant.
Some people believe that Oregano oil contributes to the growth of hair, decrease shedding and improves strength. It can also be found with thyme, rosemary and sage in some herbal based treatments to help the hair.
I was surprised to find out that oregano — while not being as obvious as gums and silicones — is said to help keep hair detangled or to somehow aid in the detangling process.
Oil of Oregano is EXTREMELY strong. One drop will be enough to overpower your toothpaste, for example, if you want to use it to fight bacteria. So when using it in any DIY product, be prepared to help cover the scent and DO NOT use too much. Literally, a few drops will be potent depending on the brand you buy.
Believe it or not, Oregano is also great to use in the maintenance of your hair. It has antioxidant and antiseptic/antibacterial properties used to help strengthen hair.
Oregano contains thymol, a known antimicrobial component which is very effective at fighting bacteria. It is apparently good for treating fungal problems, ringworm and dermatitis, and helps fight dandruff.
It’s even used to fight respiratory problems. Though I cannot confirm this information, some people believe it kills off strep and Ecoli as well. Some people use it internally to fight off colds, allergy attacks, and upset stomach.
I have Oil of Oregano (NOW brand) which is already pre-diluted with virgin olive oil. I would suggest using it the same way you would use Rosemary EO or Peppermint EO just to be safe. In other words, add it to your mixes in drops, not like you would if you were using a vegetable oil.
Source: http://www.truthinaging.com/review/make-your-own-oregano-hair-detangler
Oregano Essential Oil
http://all-hair-loss-treatments.com/oregano-oil-hair-care-growth/