If your hair feels dry no matter how much product you put in it, or if products sit on top of your strands and refuse to absorb, you have a porosity problem, not a product problem. Porosity is your hair's ability to absorb moisture and then hold onto it. Get this wrong and the rest of your routine cannot save you.
The standard advice tells you to drop a strand into a glass of water and watch whether it sinks or floats. That test is unreliable. There is a better way to figure this out, and it starts with how your hair already behaves.
What Porosity Actually Means
Think of the hair shaft as a tube with a cuticle layer of overlapping scales on the outside. Porosity is whether those scales lie flat or stand up.
- Low porosity: Cuticle is tight and flat. Water and product struggle to get in. Once moisture is in, it stays in.
- Medium porosity: Balanced. Moisture goes in and out at a normal rate. Most flexible. The fewest tradeoffs.
- High porosity: Cuticle is raised or damaged. Moisture goes in fast and exits just as fast. Hair feels dry within minutes of misting it.
These are not three discrete categories. They are points on a spectrum. You will land somewhere along it.
Why the Water Test Fails
The float test asks you to judge porosity by surface tension on a single strand. The result depends on whether the strand has product residue, whether you stirred the water, and whether the strand has any natural oils on it. Two strands from the same head can give opposite results on the same morning. Stop using it. Look at how your hair actually behaves over a week of normal washing.
How to Actually Find Your Porosity
Run through these characteristics. The pattern that matches most of your daily experience is your porosity.
Signs of low porosity:
- Water beads up on your hair when you start to wet it
- It takes a long time to fully saturate in the shower
- You get visible product buildup at the scalp or along the lengths
- Conditioners feel like they sit on top instead of soaking in
- Hair takes a long time to air dry
Signs of high porosity:
- Hair gets fully wet almost the moment water hits it
- Air drying happens fast
- Hair feels dry again within an hour of styling
- Color treatments fade quickly
- Strands feel rough or papery
If neither list matches cleanly, you are probably medium and you have less to worry about. Take the porosity quiz for a faster read on where you sit.
Why This Decides Your Routine
Porosity is not a single product to buy. It is the lens through which you build the entire routine. The same shampoo can work great for one porosity and waste another guy's wash day. Your products, your method, your wash temperature, your weekly cadence, all of it shifts based on this one variable. Treat it like a posture for everything else, not a checkbox.
Low Porosity Game Plan
Your problem is getting moisture in. Once water is in your hair, you are fine. Everything you do should focus on opening the cuticle long enough for water to enter.
- Use heat to open the cuticle. When you deep condition, sit under a hooded dryer for fifteen minutes, or wear a plastic cap to trap your own body heat. The warmth lifts the cuticle and lets the conditioner penetrate.
- Wash with warm water. Cold rinses seal the cuticle, which is the opposite of what you want when you are still trying to get moisture in.
- Pick lightweight products. Heavy butters and oils sit on the surface and add to your buildup problem. Lean toward water-based leave-ins and lighter oils like jojoba or grapeseed.
- LCO method. Liquid first (water or leave-in), then a light cream, then a light oil. The oil seals last because moisture is the limiting factor.
- Go easy on protein. Low porosity hair does not absorb protein well and feels stiff or straw-like when overdone. Once every two to three months is plenty.
- Clarify monthly. Buildup is your default failure mode. A clarifying shampoo every four to six weeks resets the slate.
The low porosity guide has the full product list and a sample week.
High Porosity Game Plan
Your problem is keeping moisture in. Water absorbs fine. It just leaves quickly. Everything you do should focus on sealing the cuticle and reinforcing the strand.
- Skip the heat tools when possible. Your hair already takes water in fast. Air dry, or diffuse on low. High heat exposes already-damaged cuticles to more damage.
- Cool water rinses. A final rinse with cool water at the end of the shower closes the cuticle and locks in what you just put on.
- Use heavier sealants. This is where shea butter and heavier oils earn their keep. After a leave-in, you need something dense to keep moisture from evaporating.
- LCO with a heavier C and O. Liquid first, then a thick cream or curl custard, then a butter or heavy oil to seal.
- Protein on a monthly schedule. High porosity benefits from protein because the cuticle has weak spots that protein temporarily fills. Once a month is the typical cadence.
- Avoid sulfates and harsh clarifiers. They strip what little moisture you managed to lock in.
The high porosity guide covers the protein-moisture balance in more depth.
Stop Arguing About LOC vs LCO
You will read fifty articles telling you LOC is for low porosity and LCO is for high. Then you will read fifty more saying the opposite. The honest answer: it depends on your specific products and your specific hair, and either order can work if your products are right.
The principle that matters: low porosity needs lightweight layers and a focus on getting water in. High porosity needs to seal that water in fast with denser products. Pick an order, run it for two wash days, and switch if it is not delivering. The acronym is not the point.
What Actually Changes in Your Routine
Once you know your porosity, audit each step against it. Here is the practical impact:
| Step | Low Porosity | High Porosity |
|---|---|---|
| Pre-wash | Optional, light | Skip oils, focus on bond repair |
| Shampoo | Sulfate-free, occasional clarify | Sulfate-free, no clarify |
| Conditioner | Lightweight, with heat | Heavier, leave-in longer |
| Leave-in | Light water-based | Cream or thicker liquid |
| Sealant | Light oil or skip | Butter or heavy oil |
| Protein | Every 8-12 weeks | Every 4 weeks |
| Final rinse | Warm to lukewarm | Cool |
For curl-type-specific tweaks, check the 4C men's page or 3C men's page.
Common Misreads
If you have low porosity hair and you are using a heavy butter cream, your hair will feel coated, your scalp will itch, and you will assume the product is bad. It is not. It is wrong for your porosity.
If you have high porosity hair and you are using a light water spray as your only leave-in, your hair will be dry an hour later, and you will assume your hair is just like that. It is not. The product is too light.
Most porosity confusion comes from running the wrong routine for years and concluding that the hair itself is the problem.
Where to Start This Week
Look at your hair tomorrow morning. Is it dry or buildup-heavy? That tells you which direction to lean. Pick one product to swap based on your porosity, run it for two wash days, and check again. Build the rest from there. The whole point of identifying porosity is that you stop guessing about why a routine that works for somebody else does not work for you.