Here are some suggested essential oils for dandruff.
Aromatherapy: A Complete Guide to the Healing Art: geranium, juniper, lavender, patchouli, rosemary, sage, tea tree, and ylang ylang.
The Complete Aromatherapy and Essential Oils Handbook for Everyday Wellness: bay laurel (Laurus nobilis), West Indian bay (Pimental racemosa), bergamot, cedarwood, clary sage, lavender, rosemary, sage, sandalwood, and tea tree.
Here's a dandruff shampoo blend from the book:
Note: This shampoo is runny and doesn't produce much lather.
The best dandruff essential oils may depend on the underlying cause of your dandruff. Here's the suggestion of one source:
An easy way to use aromatherapy for dandruff is to add a few drops of your chosen essential oil to your regular shampoo (preferably unscented, nondetergent shampoo). Adding 8 to 12 drops to an 8-ounce bottle is a good place to start, though you can use more, if you don't find it too strong.
For an anti-dandruff, conditioning blend, add 8 drops lavender and 4 drops tea tree to your 8-ounce bottle of shampoo.
Aromatherapy, A Holistic Guide to Natural Healing With Essential Oils states it's OK to use up to 80 drops of essential oil in an 8-ounce bottle of shampoo. Here's the book's suggested essential oil blend:
Here are before- and after-shampoo hair treatments for dandruff:
Source: Essential Oils Desk Reference
Post-Shampoo Dandruff Hair Rinse
Mix ingredients and shake well. Use it to rinse your hair after shampooing.
Note: The vinegar smell quickly goes away.
Source: Aromatherapy for Dummies
Also, according to the EPA, witch hazel helps fight dandruff. Add a few drops of essential oil to half a cup of witch hazel. Use the mixture as a rinse.
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