How to Wash Your Hair Scientifically

Watch more How to Bathe videos:
It's no joke: British researchers spent six months shampooing 500 volunteers until they perfected the precise technique for lustrous locks.
Step 1: Use the proper temperature
Run the water in your shower until a thermometer shows that it has reached 99.5° Fahrenheit, or 37.5° centigrade.
Step 2: Get hair completely wet
Make sure your hair is thoroughly soaked before applying shampoo.
Step 3: Don't overdo the shampoo
Drizzle a smidgen more than one teaspoon of shampoo over your scalp if you have short hair, about a half a tablespoon for medium hair, and two teaspoons for long hair. That's five, eight, and ten milliliters, respectively.
Step 4: Get in a lather
Lather up for exactly 28 seconds, using 20 rubs.
Step 5: Repeat
Rinse for exactly 22 seconds and repeat.
Step 6: Apply conditioner
Apply a little less than half a teaspoon of conditioner to short hair, a bit less than one teaspoon to medium-length hair, and a little over one teaspoon to long hair. That's two, four, and six milliliters, respectively.
Step 7: Comb through conditioner
Work conditioner through your hair with a wide-toothed comb. Leave on for 57 seconds, then rinse for 22 seconds.
Step 8: Gently towel dry
Gently pat your hair with a towel to remove excess water. Do not rub vigorously! If possible, let your hair air-dry.
Did You Know?
The average person loses 50 to 100 strands of hair from their head every day.