Scenting Shampoo With Clary Sage Oil Without Guesswork
Stir clary sage oil into a 250 ml bottle of shampoo at 1% and you have added 2.5 ml of oil, roughly 50 drops. Pump out a 5 ml squirt and that handful holds about one drop. Those two numbers explain the best way to scent a shampoo: put the oil in the bottle once, shake, and let the percentage do the work, instead of dripping oil into your palm and hoping.
Clary Sage Essential Oil
Our own Clary Sage Essential Oil, in sizes from 0.5 oz to bulk.
From $19.99
Shop Now →The numbers behind a scented bottle
Our clary sage oil is sold undiluted, and we recommend 0.5% to 2% before it touches skin. In shampoo, the shampoo plays the part of the carrier, and the percentage is oil volume over total volume. Using the common convention of 20 drops to the millilitre (a round figure, since drop size varies with the dropper):
| Shampoo | 0.5% | 1% | 2% |
|---|---|---|---|
| 100 ml | 0.5 ml, 10 drops | 1 ml, 20 drops | 2 ml, 40 drops |
| 250 ml | 1.25 ml, 25 drops | 2.5 ml, 50 drops | 5 ml, 100 drops |
| 500 ml | 2.5 ml, 50 drops | 5 ml, 100 drops | 10 ml, 200 drops |
A teaspoon of shampoo (5 ml) carries 0.025 ml of oil at 0.5%, 0.05 ml at 1% and 0.1 ml at 2%, which is half a drop, one drop and two drops. This is why "add a few drops to your palm" is a hard way to hit a number. A drop that stays undispersed is concentrated oil against your scalp, which is exactly what dilution is meant to avoid.
Which percentage? We would start at 0.5%
Rinse-off products are usually allowed a higher dilution than leave-on ones because they do not stay on the skin. The Tisserand Institute puts bath and wash-off products, including soap and body wash, at 2% to 4%, and gives 0.2% to 1% for sensitive or impaired skin. It does not list shampoo specifically, so placing shampoo in the wash-off band is our reasoning, not a quotation.
Our own guidance tops out at 2%, and a scalp is more sensitive than a forearm. Shampoo also runs down the face and into the eyes, and the European Food Safety Authority's 2024 opinion (written for animal feed) says clary sage oil should be considered an irritant to skin and eyes and a dermal and respiratory sensitiser. Putting that together, our suggestion is a simple ladder: start at 0.5%, use that bottle for a few washes, and move to 1% only if you want a stronger scent and your scalp is happy. We would not use the 2% column for a first bottle.
What goes in the bottle
We sell the oil, not shampoo, so the base is yours to choose. Pick an ordinary, already preserved shampoo from the pharmacy or grocery aisle rather than building one from scratch, since a water-based product needs a proper preservative system and that is a job for a cosmetic chemist.
Oil and water do not mix on their own. Many shampoo bases hold a little oil dispersed in their surfactants, but if you see a film or oily beads on top, the oil is not evenly distributed and the percentage on your scalp is not the one you calculated. Make a small bottle, shake before each wash, and use it up within a few weeks.
Before the first wash
- Patch test the finished shampoo, not just the oil. Our patch test guide shows how.
- Stop if you notice itching, redness or stinging, and rinse well.
- Keep it out of eyes; flush with plenty of water if it gets in, and see a doctor if irritation continues.
- Keep the undiluted bottle capped, cool and dark, away from children and pets.
This is a scent addition. We make no claim that clary sage oil changes hair growth, shedding, dandruff or scalp condition, and a persistent itchy, flaky or patchy scalp is a question for a dermatologist. We advise avoiding clary sage oil during pregnancy, and it does not belong in children's shampoo or in a pet's bath, where a pediatrician or veterinarian is the one to ask. For a leave-on version where the arithmetic is easier to control, try our scalp oil, and for general carrier maths see how to dilute clary sage oil.
Done at a low percentage and mixed evenly, clary sage turns an everyday shampoo into something that smells sweet, dry and softly herbal in the shower, and that is reason enough to try it.
Clary Sage Essential Oil
Clary Sage Essential Oil from our own shop, in sizes from 0.5 oz to bulk.
From $19.99
Shop Now →Sources & Further Reading
- Tisserand Institute. Dilution for essential oils. tisserandinstitute.org/dilution-essential-oils
- EFSA FEEDAP Panel, 2024. Safety and efficacy of a feed additive consisting of an essential oil derived from the flowering stems of Salvia sclarea L. pmc.ncbi.nlm.nih.gov/articles/PMC11561422