Every week at the chair, somebody asks how to grow their hair faster. The conversation usually opens with a TikTok, a supplement they're trying, or a trick a friend swears by. Most of it isn't true. Some of it actively damages hair. Here's what 15+ years of hands in hair has taught us about what really makes hair grow, and what just makes people poorer.
Myth 1: Trimming your hair makes it grow faster
Hair grows from the follicle, in the scalp. The ends are dead protein. Cutting the ends has zero effect on the growth rate at the root.
What's true: trimming the ends prevents split ends from traveling up the shaft, which means more of what grows actually stays attached. So you appear to be growing your hair faster because you're losing less of it to breakage. The real cadence: every 10 to 14 weeks for most clients, or every 6 to 8 weeks if you're growing through a layered cut.
Myth 2: Shampooing less makes hair grow faster
Hair grows the same regardless of how often you wash it. What changes with less washing is the appearance of length, because less manipulation means less breakage.
What's true: aggressive scrubbing, daily detangling on wet hair, and too-hot water all break the hair shaft. Washing less, washing gentler, and conditioning thoroughly does preserve length. But the follicle keeps producing at the same rate either way.
Myth 3: Brushing 100 strokes a night distributes oils and helps growth
This is Victorian advice. The original logic was that scalp sebum needs to be distributed down the shaft. The reality is that aggressive brushing breaks hair, pulls follicles, and creates split ends faster than oils can do anything beneficial.
What's true: gentle brushing twice a day with a soft-bristle or loop brush, starting at the ends and working up to the root, does help reduce knots and prevent breakage. Aggressive brushing 100 strokes a night damages your hair.
Myth 4: Biotin makes your hair grow faster
Biotin supplementation only helps people who are biotin-deficient, which is rare. For everyone else, taking extra biotin doesn't make hair grow faster. It may make your acne worse, and it definitely makes your urine more expensive.
What's true: nutritional deficiencies absolutely affect hair growth. If your hair is suddenly thinning or shedding, it's worth a blood panel through your doctor to rule out iron deficiency, vitamin D deficiency, thyroid issues, or protein deficiency. Don't self-prescribe supplements. Get tested first.
Myth 5: Rosemary oil grows hair
The TikTok favorite. The science is real but oversold. One study (small sample, single-trial) compared rosemary oil to minoxidil and found similar results over 6 months. That's interesting. It's also one study.
What's true: scalp massage with any oil increases blood flow to the follicle, which can support healthier growth. Rosemary specifically may have a mild effect. But if you have actual hair loss, see a dermatologist. If you have healthy hair and you want to try rosemary oil, it's unlikely to hurt, but it's not a miracle.
Myth 6: Cold water rinses make hair shinier and grow faster
Cold water closes the cuticle, which adds shine. That's real. It does not affect growth rate.
What's true: a cool water rinse at the end of your shower is a great habit for hair that holds color and shine longer. Skip the part about growth.
Myth 7: Wearing your hair down all the time helps growth
The thinking is that tight hairstyles cause traction alopecia, so loose hair grows faster. The first part is true. The second part isn't.
What's true: chronic tight styling (tight ponytails, slick buns daily, tight braids) absolutely causes traction alopecia, which is permanent in late stages. But wearing your hair up loosely, or in protective styles, often preserves length better than constant heat styling and friction against pillows and collars.
Myth 8: Castor oil regrows hair
No clinical evidence for hair regrowth from castor oil. Some evidence for adding shine and reducing breakage.
What's true: oils can seal moisture into the hair shaft, which prevents breakage and preserves length. They don't activate dormant follicles or speed up growth. If you want to use castor oil for shine, fine. If you're hoping for new growth on bald patches, see a dermatologist.
What actually affects hair growth
Hair grows about half an inch per month on average. The real factors:
- Genetics. Your max length, your growth rate, and your density are largely set by DNA.
- Hormones. Thyroid, postpartum, perimenopause, birth control changes, all affect hair cycles.
- Nutrition. Protein, iron, zinc, vitamin D, B vitamins. Deficiencies show up in hair.
- Stress. Acute stress can trigger telogen effluvium, temporary shedding that resolves once the stressor passes.
- Scalp health. A healthy, hydrated, exfoliated scalp grows healthier hair than a buildup-heavy one.
- Breakage management. The single biggest factor for "growing your hair longer" is reducing breakage, not increasing growth.
What we actually recommend
If you want longer, healthier hair, the playbook is boring but works:
- Trim every 10 to 14 weeks to prevent split ends from traveling
- Sulfate-free shampoo, 2 to 3 washes per week
- Bond-building treatment every 2 weeks (Olaplex No. 3 or similar)
- Heat protectant on every hot tool, every time
- Silk pillowcase or a loose braid at night
- Don't pull your hair up too tight
- Eat enough protein (most adults don't)
- See your doctor if you're shedding more than usual, get the bloodwork
- Be patient. Half an inch a month is normal. Six inches a year is fast. There is no shortcut.
When to talk to your stylist about hair loss
If you're seeing more strands in the shower drain, more in your brush, or a visibly widening part, it's worth a conversation. We're not doctors, but we see a lot of scalps every week and we can often tell when something has changed. We'll usually refer you to a dermatologist for the diagnostic, then work alongside whatever protocol they put you on.
Book a consultation
Joseph's Hair Design, 54 Wood St, New Bedford. (508) 998-7147 or book online.