Wash your hair with a clarifying shampoo and let it dry completely
Take a clean strand of hair and place it in a glass of room-temperature water
Observe how quickly the strand sinks or floats
If it floats for a long time, the hair is likely low porosity
If it sinks slowly, the hair is likely normal porosity
If it sinks quickly, the hair is likely high porosity
Spray a small section of dry hair with water and watch how it reacts
If water beads up on the surface, the hair is likely low porosity
If water absorbs at a moderate rate, the hair is likely normal porosity
If water absorbs very quickly, the hair is likely high porosity
Run your fingers up a strand from tip to root
If it feels smooth, the hair is likely low porosity
If it feels slightly rough, the hair is likely normal porosity
If it feels very rough or raised, the hair is likely high porosity
Check how long your hair takes to get fully wet in the shower
Check how long it takes to dry after washing
Compare how well your hair holds moisture and products
Look for signs of dryness, frizz, or product buildup