Question 1

Is it true that dandruff means your scalp is dry or you don't wash enough?

Accepted Answer

Myth. The NHS says dandruff isn't caused by poor hygiene, although it can be more obvious if you don't wash your hair regularly. It's linked to a yeast that lives naturally on everyone's skin, to scalp oil and to individual susceptibility — and skin conditions such as eczema. Your scalp may feel dry and itchy, but dryness is a symptom, not the cause. An anti-dandruff shampoo is the usual fix — see our dandruff guide.

Question 2

Is it true that head lice prefer dirty hair?

Accepted Answer

Myth. Head lice aren't caused by dirty hair — they're picked up by head-to-head contact (NHS). A BMJ Clinical Evidence review found no evidence that lice prefer clean hair to dirty hair or the other way round. Anyone can get them, so there's no need for embarrassment: just check and treat. See head lice and nits.

Question 3

Is it true that head lice can jump or fly from head to head?

Accepted Answer

Myth. Head lice can't jump, hop or fly — they crawl, and spread mainly by head-to-head contact (British Association of Dermatologists). They also can't be caught from pets.

Question 4

Is it true that you should brush your hair 100 strokes a day?

Accepted Answer

Myth. The American Academy of Dermatology calls this a myth: brush and comb your hair only to style it. When your hair is wet, the AAD advises using a wide-tooth comb rather than a brush. See conditioning and detangling.

Question 5

Is it true that washing your hair every day makes it fall out?

Accepted Answer

Myth. It's normal to shed around 50 to 100 hairs a day, so the hairs in the plughole were mostly already on their way out. A dermatology review says frequent washing with a well-formulated shampoo doesn't damage hair (as long as you condition), and NICE guidance for GPs says people with pattern hair loss can wash as often as they like without making it worse. Wash as often as your scalp needs — see how often to wash.

Question 6

Is it true that stress can make your hair fall out?

Accepted Answer

Partly true. Partly true. A major shock to the body — a stressful life event, severe illness or high fever, surgery, childbirth or crash dieting — can trigger telogen effluvium, a temporary burst of shedding that usually starts around three months later. It usually settles without treatment, though full volume can take months to return. Shedding that goes on for more than six months, or comes out in patches, should be checked by a GP. See telogen effluvium.

Question 7

Is it true that wearing hats causes baldness?

Accepted Answer

Myth. A 2025 review of hair-loss misinformation found no evidence that wearing hats causes hair loss — and hats usefully protect a thinning scalp from the sun. The one caveat: the American Academy of Dermatology says a hat or head covering that constantly rubs over hair pulled back tightly can contribute to traction alopecia. Keep hair loose underneath.

Question 8

Is it true that rosemary oil works as well as minoxidil for hair loss?

Accepted Answer

Unproven. This claim rests on one small trial (2015) comparing rosemary oil with 2% minoxidil in 100 people for six months. Hair counts rose slightly in both groups with no significant difference — but there was no placebo group, and later reviewers point out that the counting method wasn't fully reported and that no non-prescription product has been shown to beat minoxidil or finasteride. Interesting, but unproven. See rosemary oil.

Question 9

Is it true that silicones are toxic and ruin your hair?

Accepted Answer

Myth. An expert safety panel judged dimethicone and related hair silicones safe as used in cosmetics, and found dimethicone wasn't absorbed through the skin. In hair they reduce friction, tangling and static, and may help protect against heat and brushing. They can weigh fine hair down if you use a lot — a clarifying wash fixes that. The grain of truth: some cyclic silicones (D4, D5) are restricted in UK wash-off products because they persist in the environment, not because they harm hair. See silicones.

Question 10

Is it true that sulfates in shampoo cause cancer or hair loss?

Accepted Answer

Myth. A toxicology review found no scientific evidence that sodium lauryl sulfate (SLS) causes cancer, and none that it causes hair loss. What sulfates can do is irritate sensitive skin, especially at higher strengths — so if your scalp stings, a gentler or sulfate-free shampoo is a sensible swap. See sulfates.

Question 11

Is it true that natural or organic products can't cause allergies?

Accepted Answer

Myth. Plant ingredients can and do cause allergic reactions. Nearly 80 essential oils — including tea tree — have been reported to cause contact allergy, and dermatologists have described reactions to botanical extracts, argan oil and the protein hydrolysates used in conditioners. "Natural" isn't the same as "gentle": patch-test new products if your skin is sensitive, and stop anything that makes your scalp itchy, red or sore.

Question 12

Is it true that the right treatment can permanently repair split ends?

Accepted Answer

Myth. Hair isn't living tissue, so it can't heal once it's damaged. Protein conditioners can temporarily hold split ends together — but a dermatology review notes the effect lasts only until the next shampoo, and amino acids don't restore the damaged structure. Trimming is the only real fix; prevention (less heat, gentler detangling) does the rest. See breakage and split ends.

Question 13

Is it true that shaving makes hair grow back thicker, darker or faster?

Accepted Answer

Myth. A BMJ article on medical myths explains that clinical studies going back to 1928 show shaving doesn't change the thickness or growth rate of hair. Shaving removes only the dead part above the skin. Regrowth feels coarser because the cut end is blunt rather than tapered, and can look darker because it hasn't been lightened by the sun yet. (These studies looked at body and facial hair.)

Question 14

Is it true that alopecia areata is catching, or caused by diet?

Accepted Answer

Myth. The British Association of Dermatologists says alopecia areata can't spread to other people and that there's no connection to food or diet. It's thought to be autoimmune — the immune system attacks hair follicles without destroying them — which is why hair often grows back. See alopecia areata.

Hair and scalp myths, checked

Dandruff means your scalp is dry or you don't wash enough

Head lice prefer dirty hair

Head lice can jump or fly from head to head

You should brush your hair 100 strokes a day

Washing your hair every day makes it fall out

Stress can make your hair fall out

Wearing hats causes baldness

Rosemary oil works as well as minoxidil for hair loss

Silicones are toxic and ruin your hair

Sulfates in shampoo cause cancer or hair loss

Natural or organic products can't cause allergies

The right treatment can permanently repair split ends

Shaving makes hair grow back thicker, darker or faster

Alopecia areata is catching, or caused by diet