The short answer
No. There’s no good evidence that you can “train” your scalp to make less oil by washing less. Oil production is set by your hormones, genes and age, not by your shampoo. Hair may feel less greasy after a while because of dry shampoo or a change in what you expect, but your scalp is producing just as much oil.
What is hair training?
Hair training is the idea that if you stretch out the days between washes, your scalp will adapt and become less greasy, so you can wash less often. Some versions go further, with water-only washing or “no-poo” routines. It’s popular online, but it isn’t how the scalp works.
Why it doesn’t work
Oil, or sebum, is made by glands attached to each hair follicle. How much they make is controlled mainly by hormones and genetics, and it changes with age. Shampoo removes oil from the surface; it doesn’t tell the glands to make more. So washing less doesn’t reduce oil production; it just leaves more of it, with sweat and dead skin, sitting on your scalp.
Does water-only hair washing work?
Water rinses away sweat and loose debris, but it can’t remove oil effectively, because oil and water don’t mix. That’s what shampoo is for. Over time, water-only washing tends to leave build-up on the scalp, which can lead to itching, flaking and spots.
Why washing less can backfire
Leaving oil and sweat on the scalp can feed the yeast behind dandruff and seborrhoeic dermatitis, and irritate the follicles, causing folliculitis. Washing less doesn’t make hair grow faster either: hair growth happens inside the follicle, and an irritated scalp can add to shedding.
What to do instead
If your hair gets greasy quickly, wash it as often as it needs, often daily, with a gentle shampoo, and keep conditioner off the roots. Dry shampoo is fine now and then, but it isn’t a cleanser. If your scalp is very oily, itchy or flaky despite washing, there may be something else going on. Seborrhoeic dermatitis.
Related advice
If something isn’t right with your hair or scalp, I’ll take your history, examine your hair and scalp closely and give you a written plan. What happens at a consultation.
Questions
Can you train your scalp to produce less oil?
No. Oil production is controlled by hormones, genes and age. Washing less leaves more oil on the scalp; it doesn’t reduce how much is made.
Does washing your hair less make it grow faster?
No. Hair grows inside the follicle. Build-up from washing less can irritate the scalp and add to shedding.
Is water-only hair washing good for your hair?
Not for most people. Water can’t remove oil effectively, so build-up tends to collect on the scalp.