Hair Oiling for Hair Growth: What Does the Science Actually Say?

Hair oiling has been practised for centuries, particularly in South Asian cultures. Recently, social media has promoted hair oiling as a way to stimulate rapid hair growth, but what does the science actually show?

As a GP with a special interest in skin, I often get asked whether hair oiling is worth doing. The answer is yes—but perhaps not for the reasons many people think.

What Hair Oiling Can (and Cannot) Do

Hair oiling is best viewed as a hair protection strategy rather than a hair growth treatment.

Current evidence suggests that certain oils can:

• Reduce protein loss from the hair shaft

• Reduce friction between hair fibres

• Improve shine and softness

• Reduce breakage and split ends

• Improve hair manageability

• Protect hair from repeated washing and grooming damage

However, there is very limited evidence that hair oiling directly increases the number of hairs growing from the scalp or significantly speeds up hair growth. Most of the perceived improvement comes from reduced breakage and improved hair quality. This means hair can grow longer because fewer strands are breaking.

Which Hair Oil Has the Best Evidence?

Coconut Oil

Among all oils studied, coconut oil has the strongest scientific evidence.

Unlike many oils that simply coat the hair surface, coconut oil contains lauric acid, which allows it to penetrate the hair shaft. Some studies have shown that coconut oil reduces protein loss from both damaged and undamaged hair when used before washing.

For this reason, coconut oil remains an oil you could use to protect hair from everyday damage.

Argan Oil

Argan oil is rich in fatty acids and antioxidants and can improve hair smoothness and shine. It appears to help reduce friction and improve the cosmetic appearance of hair, although evidence for reducing protein loss is weaker than for coconut oil.

Rosemary Oil

Rosemary oil has become extremely popular online. Some small studies suggest it may have a modest benefit in androgenetic alopecia (pattern hair loss), but the evidence remains limited.

Castor Oil

Despite its popularity on social media, there is currently no good-quality evidence that castor oil promotes hair growth. It may improve shine and lubrication, but claims that it dramatically regrows hair are not supported by scientific studies.

How to Apply Hair Oil Correctly

The goal is to minimise damage to both the scalp and hair shaft.

Step 1: Apply a Small Amount to the Scalp

Using your fingertips or a dropper, apply a small amount of oil directly onto the scalp.

More is not better.

The scalp should feel lightly coated rather than saturated.

Step 2: Gentle Massage

Using the pads of your fingers, gently massage the scalp for approximately 2–5 minutes.

Avoid:

• Vigorous rubbing

• Scratching with fingernails

• Aggressive circular friction

Excessive force can increase hair breakage and may irritate the scalp.

Some studies suggest scalp massage may improve hair thickness, although evidence remains limited. The main benefit is likely improved distribution of oil and improved scalp comfort.

Step 3: Apply Remaining Oil to Hair Lengths

After lightly coating the scalp, distribute the remaining oil through the mid-lengths and ends of the hair.

This is particularly important if your hair is:

• Long

• Curly

• Chemically treated

• Colour treated

• Heat styled

The hair shaft is where oil provides the greatest protective benefit.

Step 4: Leave for a Short Period

For most people:

• 30 minutes to 2 hours is sufficient

There is no evidence that leaving oil on for 24 hours, overnight, or several days provides additional benefit.

In fact, prolonged oil exposure can increase scalp build-up and make cleansing more difficult.

Step 5: Shampoo Thoroughly

Wash with a gentle shampoo to remove excess oil.

Why Leaving Oil on for Days May Be a Bad Idea

A common misconception is that the longer oil stays on the scalp, the better the results.

Unfortunately, this is not supported by evidence.

Excessive oil accumulation can:

• Trap sweat

• Accumulate dead skin cells

• Increase scalp irritation

• Worsen itching

• Make dandruff more noticeable

• Contribute to follicular blockage in susceptible individuals

For most people, prolonged oiling simply increases build-up without improving outcomes.

Hair Oiling and Seborrhoeic Dermatitis

If you suffer from seborrhoeic dermatitis ("dandruff"), scalp oiling should be approached with caution.

Seborrhoeic dermatitis is associated with an inflammatory response to Malassezia yeast, which naturally lives on the scalp.

A heavily oiled scalp may worsen symptoms in some individuals by creating an environment that encourages persistence of scalp oils and build-up.

Patients with seborrhoeic dermatitis often notice worsening of:

• Flaking

• Itching

• Redness

• Greasiness

If you have dandruff or seborrhoeic dermatitis, focus on regular use of evidence-based anti-dandruff shampoos such as ketoconazole rather than prolonged scalp oiling.

How Often Should You Oil Your Hair?

For most people:

Dry, damaged or curly hair

1–2 times per week

Normal hair

Once weekly

Oily scalp

Every 2–4 weeks, or apply only to the hair lengths

Seborrhoeic dermatitis

Generally avoid regular scalp oiling and focus on treating the underlying scalp condition first

The Bottom Line

Hair oiling can absolutely have a place in a healthy hair care routine, but it should be viewed as a method of protecting the hair shaft rather than a miracle hair growth treatment. While certain oils can help reduce protein loss, improve shine and minimise breakage, they are unlikely to reverse significant hair thinning or address the underlying causes of hair loss.

Healthy hair growth ultimately depends on identifying and treating the root cause, whether that is iron deficiency, hormonal changes, genetics, stress, nutritional factors, menopause or medical scalp conditions.

If you are concerned about hair loss, increased shedding or thinning hair, a personalised assessment can help determine the most appropriate treatment options for you. At DermAttract, we offer doctor-led hair loss consultations and can discuss treatments including polynucleotides, microneedling and tailored medical treatment plans where appropriate.

To find out more or book a consultation, please get in touch with DermAttract.