Aspects of choosing hair and body oil you should consider include the price of products, any potential allergies you may have, and what you will be using the oil for. There are a wide range of conditions and situations which may benefit from the use of certain oils. Before making a decision, you should also ensure that you get a proper diagnosis for any issues you are having. This will help you make sure you are treating the right condition with the correct hair and body oil.
There is a large variety of hair and body oil products to choose from, and some are mixed in formulations with more than one oil or active ingredient. These are often more expensive than buying oil directly, although this can vary depending on the type of oil. If price is a concern for you, it's a good idea to shop around for various products prior to making a buying decision. Although there are several types of oils which can be used, most work equally well at moisturizing the skin and hair. The exception to this is petroleum based products, which can actually dry the skin when used for long periods of time.
If you have any allergies, you should be careful about which hair and body oil you choose. Some may contain oil derived from nuts, a common allergen. If you have an existing allergy, you should check all ingredient labels carefully to make sure you aren't covering your body with something that could make you ill. To check for an allergic reaction, even if you don't have a history of allergies, you should apply a small portion of each oil to your arm and wait to see if a reaction forms.
Different hair and body oil will work for different purposes. If you have extremely dry hair or skin, a heavier product might be in order. Olive oil is a common choice, and it can be applied directly to the skin or hair. There are also products which contain olive oil along with other nourishing ingredients. If you don't have extremely dry hair or skin, a lighter product is probably is order. For those with mildly dry hair, simply not washing it as often can allow natural oils to accumulate to remedy the situation.
Try each oil or product separately, and give each a week or so to take effect. Sometimes it can take awhile for results to be noticed. If, after this time, you don't see any results, try another product. If you have a skin condition that you are trying to treat, it is best to see a doctor for a diagnosis and treatment suggestions.