Both olive and coconut oils are beneficial in maintaining hair health, but in different ways. Whether one or the other is better for you will depend on what needs you have concerning your hair.
If your hair is dry, whether from a dry climate or the season, using olive oil can be a beneficial way to help. Olive oil, preferably extra virgin olive oil, can help nourish, help condition and strengthen your hair by warming it, combing it into your hair, and then letting it sit for a while before washing your hair in a hot shower. You can also leave it in, based upon your preferences and how much you use.
Olive oil is also good for dealing with head lice, as well as either mayonnaise or petroleum jelly. It is used to smother the lice as part of the process to wash out the lice, and can be used in conjunction with a lice comb and other methods.
Coconut oil is used in various cultures, particularly India and Sri Lanka, for haircare and hair-styling. It can be used similarly as olive oil in that it helps moisturize the scalp and hair as well as strengthens hair follicles.
Coconut oil is beneficial in thickening hair and in helping make hair curly and full as well as moisturizing and strengthening hair.
Many people believe that oils, such as olive and coconut oils, can help hair grow quicker. It is believed to improve the health of the scalp and thus stimulate the follicles and thus increase hair-growth rates.
The fact is that no reliable evidence exists to demonstrate this to be true. Hair growth can be stimulated by certain drugs and procedures and is related to genetic factors, but use of oils does not seem to have a demonstrable effect in itself on the rate of hair growth.
Leaving either oil in your hair will not harm you in any way, but whether you want to do so will depend on which oil you use and what you want your hair to look and feel like. Whether you want to leave any amount of oil in your hair will depend on how much you use, andhow oily you are comfortable leaving your hair
Both olive oil and coconut oil will be absorbed by the hair follicles to some degree, so you can wash your hair and some will remain. So long as you give the oil time to be absorbed, washing your hair will not remove all of the oil and will leave your hair more moist, shiny, and healthier.
Olive oil will tend to leave your hair looking more oily, and is thus preferred as a means to moisten and condition, rather than as a product to leave in throughout the day. Coconut oil will not leave as much of an oily residue and is preferred as a product to leave in to create a shiny look.
Some people find that leaving coconut oil in your hair results in "crunchy" or stiff hair, probably due to the fact that it helps to prevent protein loss in the hair shaft, which some people are sensitive to.
Overall, many people seem to prefer the use of coconut oil to olive oil in their personal hair care, especially if they plan to leave more of the oil in. In addition to moistening hair, coconut oil also adds thickness and body more than olive oil. However, if thickness and body are not your concern, then olive oil may be your preference.
Olive oil seems to be the preference for people who desire to moisten and condition their hair periodically, and is usually washed out after left in for a short while. Olive oil leaves a more noticeable oily look than coconut oil, and thus is preferred or not as a result, depending on what you want.