Hair Care Myths and Truths: What the Evidence Actually Says

Most hair care myths sound reasonable. That's the problem.

They get repeated by a friend, a magazine, or a relative who swears it worked. They feel like wisdom because they've been around for decades. They aren't.

This guide sets the record straight on ten ideas we hear most often — five from our recent Myths & Truths series, plus a handful more that come up daily. Each one gets the same treatment: the popular belief, what science says, and what to do instead.

No old wives' tale dressed up as expert advice. Just the truth.

Key Takeaways

• The "100 strokes a day" idea is one of the oldest haircare myths — gentle, intentional brushing your hair helps; excessive brushing damages hair cuticles and causes hair breakage

• Whether to put conditioner on the scalp depends on your hair type — dry, curly, and coily textures often benefit; fine hair and oily scalps usually don't

• Dandruff is not caused by a dry scalp — it's typically linked to Malassezia yeast overgrowth and excess oil production

• Daily washing isn't inherently bad for your hair; the right frequency depends on scalp, texture, lifestyle, and the products you use

• Trimming hair doesn't make it grow faster — but regular trims help reduce breakage at split ends, which lets your hair retain length over time

• Other myths worth correcting: plucking one grey hair doesn't bring more, heat protection isn't a free pass, dirty hair doesn't "train itself" to be cleaner, and shaving doesn't make hair grow thicker

Why Hair Care Myths Stick Around

Hair grows slowly. Habits play out over months. That gap between cause and effect is where myths thrive — you can't easily run a controlled experiment on your own head, so the loudest advice wins.

A 2020 review in the International Journal of Trichology noted that public understanding of hair and scalp biology lags well behind dermatology research. Brands have a stake in keeping it that way. So do influencers selling routines built on old wives tale logic.

The ten ideas below are the ones that come up most often in our DMs. Each correction has scientific evidence behind it.

Myth 1: Brushing Your Hair 100 Strokes a Day Promotes Hair Health

The popular belief: A vigorous nightly ritual of 100 strokes distributes natural oils, stimulates the head, and makes hair grow thicker and shinier. The truth: Excessive brushing — especially with harsh styling tools or under tension — leads to mechanical damage. Friction lifts the hair cuticles, weakens the hair shaft, and causes hair breakage and split ends. This is one of the oldest hair myths in beauty literature; it was popularized in early 20th-century etiquette manuals and is not derived from any study.

What helps instead is gentle, intentional brushing. A few thoughtful passes with a soft-bristle or wet-detangling brush is enough to detangle, distribute natural oils, and support blood flow without unnecessary stress.

What to do instead:

• Use a wet detangling brush on damp hair, working from the ends up

• Brushing wet hair without slip is a fast way to break strands. Work conditioner or a leave-in through wet hair first.

• Use a boar-bristle brush on dry hair for natural-oil distribution, no more than once or twice a day

• Stop when tangles are gone — extra strokes add risk, not benefit

Myth 2: Never Put Conditioner on Your Scalp

The popular belief: Conditioner clogs the head, causes buildup, and should always stay on the lengths. The truth: It depends on your hair and scalp type. Some people — especially those with dry or damaged hair, and those with curly, coily, or textured natural hair — benefit from hydration closer to the roots. Others with fine hair or oily, sebum-prone scalps may prefer keeping conditioner on the mid-lengths and ends.

Rinse thoroughly. Residue — not conditioner — is what leads to buildup and a flat, weighed-down feel.

This misconception comes from advice meant for fine, oil-prone hair, but it doesn’t apply to all hair types. Conditioning should always be tailored to texture and needs.

What to do instead:

Hair / Scalp Type	Conditioner Placement
Fine hair, oily scalp	Mid-lengths to ends only
Normal scalp, medium texture	Mid-lengths to ends; light pass near roots weekly
Dry scalp, dry or damaged hair	Apply through lengths and lightly massage at the roots
Curly, coily, or textured hair	Full coverage, including roots, then rinse fully

Myth 3: Dandruff Is Caused by a Dry Scalp

The popular belief: A flaky scalp means dry skin. Add more moisture and the flakes go away. The truth: Dandruff is most often linked to an overgrowth of Malassezia, a naturally occurring yeast, and is commonly associated with excess oil, irritation, and an imbalance in scalp bacteria — not simply dryness. Dry scalp and dandruff can look similar, but they are not always the same thing.

Dry scalp produces small, fine, white flakes and often comes with tight, itchy skin. Dandruff produces larger, sometimes oily flakes and tends to be persistent. The American Academy of Dermatology has published guidance recommending anti-fungal active ingredients — not heavy oils — to get rid of true dandruff.

What to do instead:

• For genuine dandruff: a medicated shampoo with zinc pyrithione, ketoconazole, selenium sulfide, or salicylic acid. Use 2–3 times a week.

• For dry scalp: a gentle, hydrating wash routine using BUR BUR Growing Season Nourishing Shampoo and Conditioner, plus a weekly scalp oil treatment and reduced hot-water exposure in the shower.

• For both: gentle exfoliation to remove dead skin cells. A weekly massage with Growing Season Burdock Hair Growth Oil supports scalp health by calming inflammation, without disrupting the microbiome the way heavy DIY oils can.

Myth 4: You Should Wash Your Hair as Little as Possible

The popular belief: Washing strips natural oils. The less you wash, the healthier your hair will be — and dirty hair eventually "trains itself" to need less washing. The truth: Daily washing your hair every day is not inherently damaging. For some hair types, it may even be necessary to remove sweat, dirt, oil, buildup, smell, and pollution. The "training" idea is folklore — sebaceous glands don't recalibrate based on wash frequency. Whether you should wash your hair regularly or stretch washes depends on your scalp, texture, lifestyle, and the shampoo you use.

This is one of the louder common hair myths from the early 2010s, when the "no-poo" movement went mainstream. The original advice was sound for some — over-washing fine hair with sulfate-heavy shampoo strips natural oils and increases frizz. But the conclusion ("wash as little as possible") got applied to everyone. For athletes, urban dwellers, and people with oily scalps, going days between washes does more harm than good. Greasy hair can also trap bacteria against the skin and create the conditions for dandruff to worsen.

What to do instead:

Scenario	Recommended Washing Frequency
Fine, oily scalp, urban environment	Daily or every other day with a sulfate-free shampoo
Normal texture, light activity	2–3 times per week
Curly, coily, or textured hair	1–2 times per week with gentle cleansers
Heavy gym/pool / sweat lifestyle	After every workout, alternating between a gentle wash with co-wash

Use a sulfate-free shampoo if you wash frequently. The cleansers don't need to be aggressive to be effective — a gentle lather is enough. Rinse with cold water for the last 15 seconds; it helps the cuticle lie flat and adds shine.

Myth 5: Trimming Your Hair Makes It Grow Faster

The popular belief: Regular trims accelerate the speed at which your hair grows. The truth: Hair growth happens at the follicle, deep beneath the skin — not at the ends. Trimming hair doesn't change the rate at which your hair grows. However, trimming damaged strands or split ends can reduce hair breakage, allowing your hair to retain length and appear healthier.

Hair grows about half an inch a month on average. That number is determined by genetics, hormones, nutrition, scalp health, and overall hair health — not your last haircut. Regular trims help prevent split ends from traveling up the hair shaft, which is what makes long hair look thin, scraggly, and stuck at the same length for years.

What to do instead:

• Get regular trims every 8–12 weeks for most hair types; every 12–16 weeks for curly and coily textures

• Focus growth efforts on the follicle: nourish the scalp, eat enough protein and iron, manage stress, and avoid traction styles that pull hair from the root

• Use a weekly pre-shampoo oil treatment to reduce damage along the lengths

• For thinning hair or noticeable hair loss, see a dermatologist or trichologist — not a stylist

• A weekly massage with Growing Season Burdock Hair Growth Oil supports the scalp where hair growth actually happens. The trim handles the ends. Two different jobs.

Myth 6: Plucking One Grey Hair Makes Two Grow Back

The popular belief is that plucking a grey hair causes more to grow in its place. This isn’t true. Each follicle produces a single hair, and removing one doesn’t affect surrounding follicles or trigger additional greys.

That said, plucking isn’t recommended. Repeated pulling can irritate or damage the follicle over time, potentially leading to weaker regrowth. If a grey hair is noticeable, trimming it at the base is the safer option.

Grey hair develops when pigment production in the follicle naturally slows or stops. This is primarily genetic and a normal part of the hair growth cycle. While many factors are often discussed in relation to greying, no topical product has been proven to reverse it.

What to do instead:

• Leave grey hair as is, or trim it at the base if preferred

• For coverage, consult a professional colorist for a tailored approach

• Focus on consistent, gentle hair care to support overall hair health

Myth 7: Heat Protection Makes Heat Styling Safe

The popular belief: Spray on a heat protectant and you can use straighteners and other styling tools daily without consequences. The truth: Heat protection reduces damage. It doesn't eliminate it. A good heat protectant raises the temperature at which proteins start to break down and adds a slip layer that distributes heat more evenly. But repeated exposure to temperatures above 350°F still causes cumulative damage — bubble formation in the cortex, weakened hydrogen bonds, lifted cuticle, and visible breakage over time.

This is one of the more recent hair care myths, fueled by product marketing. Heat protection is real and worth using. It just isn't a license to flat-iron daily.

What to do instead:

• Always use heat protection before any blow dry, flat iron, or curling tool — it helps the product penetrate the cuticle and create a thermal barrier

• If your hair feels dry and brittle, or has shorter, broken pieces at the front, that's cumulative heat damage. No amount of conditioner reverses it — only time and trimming.

• Keep heat tools at 300–375°F for fine to medium textures, no higher than 400°F for coarse hair

• Limit direct heat styling to 2–3 times a week

• Air dry on rest days — let your hair recover (and yes, that's its own routine)

   

Myth 8: You Should Never Brush Wet Hair

The popular belief: Strands are fragile when wet, so brushing always causes breakage. The truth: Wet hair is more elastic and more vulnerable than dry — but it tangles less when handled correctly. The rule isn't "never brush wet hair"; it's "never brush wet hair with the wrong tool or technique."

A wet detangling brush with flexible bristles, used after conditioner has been worked through, glides through without breaking strands. For curly and textured hair, this is actually the gentlest time to detangle, because conditioner adds slip that dry detangling can't match.

What to do instead:

• Apply conditioner, work it through with your fingers, then use a wet detangling brush from ends up

• Never use a fine-tooth comb or stiff boar bristle on wet strands

• For coily hair, detangle in the shower with conditioner still in

• Use cold water for the final rinse to help the cuticle seal before brushing

A Few More Hair Myths Worth Correcting

Not every haircare myth needs its own deep dive. Here are a few more that come up often — short answers, straight to the point.

Myth	Truth
"Shaving your head makes hair grow back thicker"	An old wives' tale heard since childhood. Shaving has no effect on the follicle. Regrowth feels coarser because the blunt cut end is wider than a tapered tip — that's it. Shaving doesn't help bald spots either.
"Sleeping with wet hair in bed will give you a cold"	Colds are caused by viruses, not damp hair. Going to bed with wet hair does increase friction breakage on the pillow, so wrap in silk or wait until it's mostly dry.
"Rosemary oil cures hair loss"	A small body of research shows rosemary oil may modestly support hair growth in androgenetic hair loss — but it's not a cure and not a substitute for evidence-based treatments. See a dermatologist for diagnosis first.
"Lemon juice safely lightens hair"	Lemon juice plus UV rays does lighten — but it also raises the cuticle and dries out the hair shaft, leading to long-term damage. Use a professional lightener instead.
"Sulfate free shampoo is always better"	Gentler, yes — but some scalps need stronger surfactants to remove buildup. It depends on your hair.
"Dry shampoo is bad for your hair"	Not bad in moderation. Daily use without washing leads to scalp irritation and clogged follicles. Use it as a tool, not a substitute for washing.
"Cutting hair on a full moon makes it grow thicker"	Pure folklore. The moon doesn't influence hair follicles.
"Cold water rinses make hair shinier"	Slightly true — cold helps the cuticle lie flat, which reflects light more evenly. Shinier hair is the real but modest result, not a transformation.
"Conditioner causes hair loss"	A persistent old wives' tale. Conditioner doesn't reach the follicle and can't cause shedding. What you see in the drain during a wash is normal daily shedding.

These cluster under the same pattern as the bigger common hair myths: a kernel of something real, scaled into a universal rule it doesn't deserve.

How to Build a Routine on Truths, Not Myths

If you strip away the haircare myths, what's left is unglamorous and reliable:

1. Wash on the schedule your scalp needs, not on a rule you read somewhere. Use a sulfate-free shampoo if you wash frequently; a gentle cleansing shampoo otherwise.

2. Condition based on type. Fine hair stays on lengths; dry, curly, or coily textures benefit from coverage closer to the head.

3. Detangle wet hair gently with the right tool — not aggressively, not with the wrong tool. The goal is to reduce friction, control breakage, and seal the cuticle.

4. Use heat protection before styling tools, and limit heat styling to 2–3 times a week.

5. Treat the scalp like skin. Weekly oil massage, gentle exfoliation, no harsh chemicals — that's the same way good skincare works.

6. Get regular trims every 8–12 weeks for split ends — to reduce frizz, not to "make hair grow."

7. Support growth from the inside. Protein (a steady supply of amino acids), iron, B vitamins, and omega-3s. Topicals support; nutrition builds.

A weekly ritual with Growing Season Burdock Hair Growth Oil, a sulfate-free wash, and a gentle wet-detangling routine covers most of what your hair needs to stay in optimal condition. Everything else is built on top.

The Take-Home

Brush gently. Condition based on type. Wash on the schedule that suits your scalp. Don't pluck grey hair. Use heat protection. Trim to reduce frizz and breakage, not to create growth. Treat the scalp like skin.

The science is unglamorous. But it works the same way every time.

That's the difference between haircare myths and hair care.