From Uncle Harry's website:

This hair and scalp elixir is a pH balancing root stimulator. It can return natural acidity to the skin, clears buildup, and promotes blood flow to promote hair growth and a healthy scalp. Gluten free and vegan.

Ingredients Organic apple cider vinegar, essential oils of eucalyptus, niaouli, lemon, rosemary, camphor, tea tree, clove, peppermint, and oregano. 

Directions Shake well before use. Add six to ten drops directly to roots of hair and massage vigorously with fingertips. Leave in for thirty minutes or overnight. Shampoo out. External use only.