The best oil for low porosity hair is usually a light one, used sparingly: jojoba, grapeseed, squalane or hemp seed, applied to damp hair so it spreads thin. Medium porosity hair gets along with most oils, and argan, camellia or apricot kernel are easy places to start. High porosity hair tends to prefer richer oils that stay on the surface longer, such as sweet almond, virgin coconut or avocado. Porosity isn't the only factor, but it's a useful way to narrow the choice.
What hair porosity means
Porosity describes how readily your hair takes in water, and oil, and how quickly it lets them go. It comes down mostly to the cuticle, the overlapping layer of cells on the outside of each strand.
- Low porosity: a tight, smooth cuticle. Hair is slow to get wet and slow to dry. Products tend to sit on top.
- Medium porosity: a cuticle in good order. Hair takes up water at a moderate pace and holds styles well.
- High porosity: a raised or worn cuticle. Hair soaks up water fast, dries fast, and often feels dry or frizzes in humidity.
The three-level scale is a hair-care convention, not a lab measurement. What research does show is that damage raises porosity. A review of hair cosmetics in the International Journal of Trichology puts it plainly: hair is porous, and damaged hair is intensely so. Bleach, color, chemical straightening and heat can all move hair toward the high end. So can age: the ends of long hair are often more porous than the roots.
How to tell your hair porosity
There's no exact home test. These everyday signs are a better guide than any single trick.
- Wetting: in the shower, does water bead and run off, or does your hair soak through at once?
- Drying: does your hair take hours to air-dry, or is it dry soon after you towel it?
- Products: do oils and creams sit on top and feel greasy, or vanish and leave hair dry again within a day?
- History: have you bleached, colored, relaxed or regularly heat-styled your hair?
Slow to wet, slow to dry, products sit on top: probably low. Fast to wet, fast to dry, products disappear, a history of processing: probably high. Somewhere between: medium.
You'll often see the float test, where you drop a strand in a glass of water and watch whether it sinks. It's a rough guide at best. Oil, product residue and the water's surface tension all change the result, so don't let one glass decide for you.
Best oils for low porosity hair
Low porosity hair takes in oil slowly, so most of what you apply stays on the surface. A rich oil can sit there, looking greasy and weighing hair down. The aim is a thin, even layer of a light oil.
- Jojoba: light and quick to settle. A good default.
- Grapeseed: very light, with little feel on the hair.
- Squalane: almost weightless, and very stable in the bottle.
- Hemp seed: light, used as a smaller share in a blend.
How you apply it matters as much as which oil. Use it on damp, not dry, hair so it spreads more easily. Use less than you think. A little warmth helps too: oil warmed between your palms spreads further, and some people put a shower cap on during a pre-wash. For more on choosing by weight, see light vs heavy hair oils.
Best oils for medium porosity hair
Medium porosity hair is the most forgiving. Almost any oil works if you match the weight to the thickness of your strands. Fine strands do better with light oils; thick strands can take more.
- Argan: medium-light, adds shine and softness without much residue.
- Camellia (tsubaki): medium-light with good slip, often used for shine.
- Apricot kernel: soft and easy to wash out.
If you're deciding between the two most common picks, our comparison of jojoba vs argan oil for hair lays out the difference.
Best oils for high porosity hair
High porosity hair takes in water and oil fast and lets them go fast. It usually likes a richer oil that stays on the surface longer, smoothing a raised cuticle and adding slip. It can also take larger amounts without looking greasy.
- Sweet almond: rich and soft. Contains tree nut.
- Virgin coconut: rich, and solid below about 76 °F (24 °C).
- Avocado and olive: rich; used as part of a blend rather than alone.
- Castor: very thick. A small share adds weight and gloss to a blend.
- Baobab and marula: rich, with a smooth, conditioned feel.
On high porosity hair, oil works best layered over moisture. Apply it to damp hair after conditioning, or as a pre-wash before shampoo. Our guide to pre-poo covers the second option.
Oils by porosity at a glance
| Oil | Weight | Low porosity | Medium porosity | High porosity |
|---|---|---|---|---|
| Jojoba | Light | Good fit | Good fit | Light finish only |
| Grapeseed | Light | Good fit | Good fit for fine hair | Often too light |
| Squalane | Light | Good fit | Good fit | Light finish only |
| Argan | Medium-light | Small amounts | Good fit | Good fit |
| Camellia | Medium-light | Small amounts | Good fit | Good fit |
| Sweet almond | Medium-rich | Can sit heavy | Good fit for thick hair | Good fit |
| Virgin coconut | Medium-rich | Can sit heavy | Pre-wash | Good fit |
| Avocado | Rich | Not usually | Small share of a blend | Good fit in a blend |
| Castor | Rich | Not usually | Small share of a blend | Small share of a blend |
These are tendencies, not rules. Hair is often mixed: low porosity at the roots, high at the bleached ends. Give each part what it needs, and go by how your hair feels.
What research says about oils and porous hair
Not every oil behaves the same on hair. In a 2005 study in the Journal of Cosmetic Science, Keis and colleagues measured how strongly oiled hair fibers stuck to each other. With coconut, olive and sunflower oils, that pull weakened over time; with mineral oil, it did not. Gentle heat weakened it further for coconut and sunflower. The authors' explanation was that the plant oils were moving into the fiber, leaving a thinner film on the surface.
Damage changes how much gets in. A 2024 study in Cosmetics by Lourenço and colleagues compared coconut, avocado and argan oils on virgin and bleached hair. All three got further into the bleached hair. The same study also found the oils' effects on the fiber depended on the oil, the level of damage and the humidity. The authors' conclusion was a measured one: plant oils are not automatically good for every hair, and their chemistry matters.
That fits everyday experience. Porous hair takes in more of what you give it, and the choice of oil matters more.
Building a blend for your porosity
A single oil is a fine place to start. A blend lets you set the weight more precisely: a light base with a small share of something richer, or the other way round. The quiz asks five questions about your hair type, thickness, scalp and goals, and suggests a formula. Read your porosity alongside it: if your hair is high porosity, lean toward the richer suggestions; if low, the lighter ones. You can change any oil or amount in the builder before we blend it.
FAQ
Is coconut oil good for low porosity hair?
It can be, in small amounts and as a pre-wash. Virgin coconut is a rich oil, and on low porosity hair it can sit heavily and feel waxy, especially in a cool room where it starts to set. If it does, switch to a lighter oil for leave-in use.
Can hair porosity change?
Yes. Bleach, color, chemical straightening and frequent heat raise porosity over time. The hair nearest your scalp is the newest and closest to your natural porosity, so long hair is often mixed from root to tip.
Is the float test accurate?
Not very. Product residue, oil and surface tension all affect whether a strand sinks. How your hair wets, dries and handles products is a more reliable guide.
What is the best oil for high porosity hair?
Usually a richer oil, such as sweet almond, virgin coconut, or a blend with a small share of avocado or castor. Apply it to damp hair after conditioning, or as a pre-wash.
