FREE: 10ml Peppermint Essential Oil - Pure Undiluted Organic Therapeutic Grade - Free Shipping!

I can't. Sorry!

Peppermint oil is very healthy for the hair and scalp for a few reasons:
1. It balances the ph level of your scalp, which reduces oil production.
2. It's an oil, so it also helps a dry scalp. It may seem oxymoronic when comparing this benefit to the first I listed, but it reduces each problem via different methods.
3. Peppermint oil stimulates your hair follicles which, as you guessed it, promotes hair growth!
4. An added bonus: Bed Bugs, Lice, Scabies, etc do not like peppermint! In fact, peppermint oil is very good at getting rid of these infestations, if you ever have the unfortunate experience of providing home to them.

I use peppermint oil in my hair every single time I shower. I'm all-natural so I don't use products that contain Sodium Lauryl Sulfate, Propylene Glycol, Aluminum etc. (read your shampoo bottle, deodorants, etc. then google it's ingredients, and you will like likely stop using them too ;)

What I do:
Scrub my hair/head with baking soda.
Rinse with water.
Rub in a small amount of diluted red wine vinegar to neutralize any remaining sodium bicarbonate. (other vinegars work, too)
Rinse.
Put 1-2 drops of peppermint oil on my hand, rub my hands together, then with my head tilted back to prevent it from running down onto my face, I run my hands through my hair. Then I allow very warm water to run through my hair.

It sounds like a hassle, but it's not really. I keep baking soda in a sealed plastic container, in my shower. I also have an old liquid-soap bottle with half red-wine vinegar, half water mixed.
I've found it's actually quicker cleaning this way, because the products used are water-soluble and rinse out easily, unlike traditional shampoos.

The peppermint oil can be added to hair after showering as well. I just prefer to do it while showering.

Hope my answer wasn't too overwhelming! :P