Neem oil is derived from crushing the seeds of the Neem plant. It is a powerful anthelmintic compound and has a very wide spectrum of action and is highly medicinal in nature, which includes being a spermicidal compounds as well as anti-bacterial, anti-fungal, etc. It should be used only externally. In folk medicine, it was used to control respiratory disorders, constipation, leprosy, as well as a general tonic. It has anti-inflammatory, antipyretic (relieving fever) and analgesic (relieving pain) activity and possesses immunostimulant activity which increases the body’s defense mechanism to fight infectious organisms and other foreign material. It's effective against fungal infections and bacterial infections on the skin. It can be used to kill lice in your scalp. It is not recommended to use internally. Also neem oil should be diluted when applied directly to skin. Mix with water for your skin. You can add a few drops to your shampoo to fight lice and dandruff. Mix 1 part with 4 parts of a carrier oil like jojoba oil or grapeseed oil for fungal infections and bacterial infections.