Understanding Aromatherapy: Why Essential Oils Must Be Diluted

Aromatherapy and its use of essential oils is varied and dictated by modes of application: olfaction, inhalation, RESPONSIBLE internal use (e.g., suppositories, enteric capsules for acute symptoms) and the dermal pathway.  Dermal usage is vast: neat application, frictions, oils/lotions/creams/serums, baths, scrubs/glows, roller ball applicators. (Note: I do not get into dilution for internal use here.)

The dermal pathway is one of greatest concern when it comes to dilution as the irresponsible, unwieldy use of many essential oils may cause dermal irritation and lead to sensitization.

These DIY Classes Help You Safely and Easily Incorporate Essential Oils into Aromatherapy Products!

The concentrated, potent nature of essential oils necessitates dilution.

Think about it. Essential oils are precious resources. They are HIGHLY CONCENTRATED, POTENT, VOLATILE MOLECULES. The aromatic plants do not produce their essences 24/7, 365 days a year. The aromatics create essences at certain times of the day and at certain times of the year–and overall, each plant does not produce a whole lot of essence. Lavender (Lavandula angustifolia) may be harvested twice a year, a sandalwood (Santalum album) tree must grow to be FORTY years old until it can be CUT DOWN to take its heartwood. To obtain 1 kg of essential oil you need the following: 20-30 kg of fresh Zingibere officinalis rhizome, 150 kg of Lavandula angustifolia, 40-90 kg of Cymbopogon citratus/nardus, 1 ton of Helichrysum italicum, 5-10 tons of Melissa officinalis. 

Also, it is shown that more drops of essential oil have the opposite of the desired effect (i.e., more lavender may cause excitation). For that matter, 1 DROP of essential oil has therapy and is enough to communicate with the nervous system.

It all comes down to number of drops.

Not grams or milliliters but a rather unscientific “number of drops”. Aromatherapy is an art and a science about molecular communication, so “drops” as a base and guideline are just fine. But…I find that many aromatherapy books and classes don’t actually TELL YOU what a drop is. Let’s get into how “drops” are derived and relate to dilution…

Accepted facts:

• There are 20-25 drops of essential oil in 1 ml.
  • The “drop” is pretty standardized through orifice reducers, droppers and pipettes. (Were you into repeatable manufacturing you would weigh materials anyway.)
• 30 ml = 1 ounce
• 1 ounce is 600 drops

If I want 1% dilution:

• 30 ml = 1 ounce = 600 drops. 1% of 600 is 6.
• That translates to 6 drops of EOs to 1 ounce of carrier.

Following is a table that uses “# of drops” as the base of the whole table:

# of drops	ml	oz.	0.50%	1%	2%	2.5%	3%	5%
600	30	1	3	6	12	15	18	30
1200	60	2	6	12	24	30	36	60
1600	80	3	8	16	32	40	48	80
2400	120	4	12	24	48	60	72	120

How to read the table:

• If you are looking for a 1 ounce bottle of a FACIAL oil, use a dilution between .5 & 1.5% (6 to 10 drops per ounce).
• If you want to make a 2 ounce bottle of BODY oil and use the holistic aromatherapy rate of 2.5-3%, you need ~30 drops of essential oils.
• If you are making a 4 ounce batch of all-purpose salve, consider using a 3% to 5% dilution rate–that’s 72 or 120 drops of essential oils, respectively. (Note: wax holds the oils in a certain way and it’s OK to use this much essential oil.)

That’s it.