Applications
Castor oil is thick, slow to absorb and stays where you put it. That one property decides everything on this page: how much to use, how long to leave it on, and how to get it back out again.
Here is what works, part of the body by part of the body.
Why it behaves this way
Castor oil is mostly ricinoleic acid. Ours tests at 90%, with 3% oleic acid and 4% linoleic acid. That single figure explains most of how the oil behaves in your hands.
Ricinoleic acid carries an extra hydroxyl group that the common fatty acids in other plant oils do not. It is why castor oil is dense and faintly tacky rather than thin and quick to run, and why it clings to a hair or a cuticle instead of sliding off it.
The practical upshot: castor oil suits the places where you want a very small amount to stay exactly where you put it — a lash line, the skin around a nail, a parting in the scalp. It is the wrong choice anywhere you want an oil to absorb and vanish.
It is also why removing it takes a deliberate wash. Water alone will not shift it.
01
Warm it
Put two or three drops in your palm and rub your hands together. Warming thins the oil noticeably and makes it spread instead of sitting in one spot.
02
Press, do not rub
Press the oil in with flat fingers, or massage it into the scalp in small circles. Pressing beats dragging a thick oil across skin.
03
Give it time
Castor oil absorbs slowly, which is the point. Apply at night and let it sit while you sleep, on a pillowcase you do not mind oiling.
Scalp and hair
A teaspoon for short hair, two for long. Part the hair, work it onto the scalp with your fingertips, then smooth what is left through the bottom third. Leave 30 minutes, or overnight.
Lashes and brows
A brush wiped almost dry. Comb through brows the way the hair grows, then along the upper lash line only. Blot with a tissue. Never the lower lash line.
Face and skin
Two drops over clean, slightly damp skin as the last step at night. Dry elbows, knees and heels will take more than your face does.
Nails and cuticles
One drop per hand, worked around the base of each nail and pulled over the tips. Nothing to wash off, which makes this the easiest one to keep up daily.
Body and packs
A cloth soaked in oil, held against the skin for 20 to 60 minutes with something warm on top. Uses far more oil than any other application.
Same oil in both bottles. Pick the size that fits how you will use it.
Quick reference
Scalp and hair. One to two teaspoons, once a week, the night before you were going to wash it anyway.
Lashes and brows. A brush wiped nearly dry, once a day, at night.
Face. Two drops, at night, two or three times a week.
Nails and cuticles. One drop per hand, daily. This is the one worth doing every day, because there is nothing to wash off.
Everywhere. If it still feels tacky after a few minutes, you used too much. Halve it next time rather than washing it off.
The part people get wrong
This is what puts people off castor oil, and it comes down entirely to the order you do things in.
Shampoo dry hair first, before any water. Work neat shampoo into oiled, dry hair and massage it through. Shampoo binds to oil far more effectively when it is not competing with water.
Then add a little water and keep working until it turns milky. That is the oil lifting.
Rinse, then shampoo a second time the normal way. Two washes, not five.
On skin, a warm damp cloth does it, and a little bicarbonate of soda dissolved in warm water cuts the oil faster than water alone.
If your hair still feels coated after two washes, the answer is less oil next time, not more shampoo.
Safety
Patch test first. Put a little on the inside of your forearm and leave it a day before using it more widely, as you would with any new oil.
Less than you think. Pure castor oil is thick. If it feels tacky, that is a sign to use fewer drops next time rather than to wash it off.
Keep it away from the eye itself. Along the upper lash line, not the lower one, and blot afterwards. If any gets in, rinse with clean water and let your vision settle.
Contact lenses out before you apply anything near the lash line, and left out until you have washed it off. If you wear lash extensions, skip the lash line entirely — oils break down the adhesive.
Do not swallow it. Castor oil is a potent laxative taken internally. This is sold for external use.
Ask first if it matters. Speak to a doctor or pharmacist if you are pregnant or breastfeeding, if you take a prescription eye product, or if you are dealing with a skin condition. Stop using it if your skin reacts.
Store it cool and capped. Out of direct sun, with the cap closed. No refrigeration needed.
