The short answer: hair growth oils can make hair feel softer, look shinier and break less, which helps hair stay longer. But there is little solid evidence that any oil makes hair grow faster or thicker. The best-known study on rosemary oil was small and has real flaws, and for castor oil there are no robust trials. For children, use a small amount, patch test first, and see your GP if you are worried about hair loss.
Last updated: October 2026.
If you have ever stood in the hair aisle wondering whether a "growth oil" is worth buying for your child, you are in good company. This guide explains what these oils can and cannot do, what the research says about rosemary and castor oil, how to use an oil safely on curly and afro hair, and when to talk to a doctor instead. It is general information, so treat it as a starting point and not a promise.
Quick reference
| Ingredient | What the evidence says | Worth knowing |
|---|---|---|
| Rosemary oil | One small 2015 trial, with flaws. Not proven | Can irritate skin. Needs dilution |
| Castor oil | No robust trials for hair growth. Cosmetic benefits only | Heavy. Too much can tangle curly hair |
| Moringa and neem | Common in hair oils. We make no growth claims for them here | Patch test, as with any new product |
| Scalp massage | Gentle and low risk, whatever oil you use | Soft fingertips, no scrubbing |
These are summaries from secondary sources, so they are a guide and not medical advice.
In this guide
What a hair growth oil can realistically do
Hair grows from the follicle under the scalp, and an oil sits on top of the hair and skin. So an oil is unlikely to change how fast your child's hair grows. What it can do is coat the hair, hold in moisture and make strands more flexible. Tightly coiled hair tends to be drier because scalp oils find it harder to travel along each curl, so softer, better-moisturised hair often breaks less. That can mean more length is kept over time.
In other words, the benefit most parents notice is less breakage, not faster growth. If your child's hair seems to stay the same length, breakage is the first thing to look at. Our guide to the causes of breakage goes through it.
Rosemary oil: what the research shows
Rosemary oil is the ingredient most often linked to growth claims, and it usually traces back to one study published in 2015. It compared rosemary oil with 2% minoxidil in about 100 people over 6 months and reported similar results in both groups. A review of that study by a cosmetic science writer points out several limits (source: Lab Muffin):
- Six months is short for judging hair growth, which can take a year or more to show.
- There was no placebo group, and the comparison dose of minoxidil was the lower one.
- Some numbers in the paper look inconsistent, so the results are hard to rely on.
- Participants massaged their scalps twice a day, which may have affected the outcome.
- Scalp itching was reported more often in the rosemary group.
The takeaway is that rosemary oil may be pleasant to use, but it is not a proven growth treatment. If you try a product that contains it, patch test first and stop if you see redness or itching. Rosemary essential oil is strong, so we do not suggest using it undiluted, and we would check with a pharmacist before using it on a young child.
Castor oil: popular, but not proven
Castor oil is thick and sticky, which many people with curly and coily hair love for sealing in moisture. A UK pharmacy guide says there is no robust trial evidence that it stimulates hair growth, and describes its benefits as cosmetic, such as helping hair hold moisture and break less. It also notes that castor oil is a cosmetic ingredient in the UK and is not licensed by the MHRA for hair loss (source: Bolt Pharmacy).
The same guide lists some risks worth knowing:
- Skin irritation (contact dermatitis) or sore bumps around the follicles.
- Acute hair felting, where hair knots into a tight mat. It is more likely with heavy use, and curly and textured hair can be more prone.
- It should never be swallowed.
Its practical advice for adults is to dilute castor oil with a lighter oil, patch test for 24 to 48 hours, use it once or twice a week and wash it out thoroughly. Less is better, especially on children's fine, curly hair.
How to use an oil on your child's hair
Whatever oil you choose, a gentle routine matters more than the label. Always follow the directions on the product you are using.
- Patch test first. Put a tiny amount on the inner forearm and wait 24 to 48 hours. Skip the product if you see redness, itching or swelling.
- Start with damp or moisturised hair. Oil holds moisture in, it does not add it. See our LOC and LCO guide for the layering order.
- Use a few drops. Warm them between your fingers, then smooth over the lengths and ends first.
- Massage the scalp lightly with your fingertips for a minute or so. Keep it soft, especially around the hairline.
- Style loosely. Avoid pulling on the edges.
- Wash it out regularly. Build-up can leave hair heavy and dull. Our wash day routine by age covers how often.
Little and often. A few drops used regularly is better than a lot used once. If the hair feels greasy or sticky, you have used too much.
6 mistakes to avoid
- Expecting overnight growth. Hair grows slowly, and any change takes months, not days.
- Using too much. Heavy oils can weigh hair down and build up on the scalp.
- Skipping the patch test. Natural does not mean no reaction.
- Putting oil on a sore, flaky or broken scalp. See a pharmacist or GP first.
- Using adult strength products on small children. Check the label and ask a pharmacist if unsure.
- Ignoring breakage. If hair snaps near the ends, fixing handling and moisture will help more than any oil.
Oils and serums we make
Here is how our oils and serums are described on their product pages. Please read the full ingredients and safety notes on each page before buying, and patch test first. We do not promise results, and individual hair varies.
| Product | What it is for |
|---|---|
| Kids Mega Hair Growth Oil (Moringa and Neem infused) | A lightweight oil made for children's hair, described as moisturising and helping to reduce dryness and breakage |
| Edges Booster Serum | A serum for the hairline. The product page lists rosemary and castor oil and says to keep it out of reach of children |
| Antidandruff Oil | A scalp treatment oil for dandruff. The page lists castor and rosemary oil among its ingredients |
| Kids Hair Growth Set 6-in-1 | Shampoo, leave-in conditioner, oils, butter and edges serum in one routine |
Browse the full Kids Hair Care collection or our Hair Treatment collection. For more on the topic, read our natural hair growth guide for kids.
When to see a doctor
An oil cannot fix every cause of hair loss. Talk to your GP or pharmacist if your child has:
- sudden, patchy or rapidly spreading hair loss
- a scalp that is painful, very red, scaly, crusted or has pustules
- scaly scalp patches with swollen glands in the neck, which can be a fungal infection (tinea capitis) that needs prompt treatment
- a reaction after using a new product, such as swelling, hives or breathing difficulty (call 999 for a severe reaction)
A GP can check for causes such as low iron or thyroid problems where it makes sense to do so.
This article is general information, not medical advice.
FAQs
Do hair growth oils actually work?
They can make hair softer and less prone to breakage, which helps it keep its length. There is little solid evidence that an oil makes hair grow faster.
Does rosemary oil make hair grow?
It is often claimed, but the main study was small, short and had flaws. Rosemary oil is not a proven treatment, and it can irritate skin.
Is castor oil good for kids' hair?
It is a heavy oil that some people use for moisture. Evidence for growth is lacking, and too much can tangle curly hair, so use a very small amount and patch test first.
How often should I oil my child's hair?
Many parents use a few drops once or twice a week and wash it out regularly. Follow the directions on your product.
Can I use hair oil on a baby?
The NHS advises avoiding oils and lotions in a baby's first month. See our baby afro hair care guide and ask your health visitor if unsure.
Why is my child's hair not growing?
Hair often looks stuck because the ends break as fast as the roots grow. Reducing breakage, keeping hair moisturised and handling it gently usually helps more than adding a product.