Does Rosemary Oil help hair grow?
By now, we have seen and heard about it everywhere - the amazing powers of rosemary as nature's secret to thicken and regrow hair. As most people on their hair growth journey, I wanted to know more - how much of this is true? Has that unused bottle of rosemary oil that has been sitting in my bathroom cupboard for years really been the answer to my hair growth dreams? I had no option to put on my investigative goggles and do some digging into the data.
Can rosemary oil regrow or thicken hair?
To cut right to the point, the short answer is maybe. Am I still going to invest in using rosemary oil long term for hair growth? Yes.
You may have heard of a 2015 study that compared the efficacy of Minoxidil, an over the counter hair growth drug, to rosemary oil. This study concluded that both groups showed significant new hair growth at the 6-month mark. [1] In this specific study, patients were given a rosemary oil lotion with at least 3.7mg of 1,8-cineol per 1ml of the product (1,8-Cineole is one of a number of volatile organic compounds present in the essential oil of rosemary). The rosemary oil group applied 1mL of the solution twice a day to the frontoparietal and vertex areas of the scalp with gentle massage at 12 hr intervals for 6 months.
Looks promising. But by how much did the hair count increase by?
When looking at the data, it seems that both groups had no significant change in hair growth at the 3 month mark, however a significant increase in hair growth at the 6-month end point compared to the baseline. A gentle reminder to myself that consistency is key.
|
Mean hair count
|
2% Minoxidil
|
Rosemary Oil
|
|
Baseline (0 months)
|
138.4
|
122.8
|
|
3 months
|
138.4
|
122.8
|
|
6 months
|
140.7
|
129.8
|
|
change
|
1.7%
|
5.5%
|
This study would suggest that the rosemary oil group saw a 5.5% increase in hair count, while the 2% group saw a 1.7% increase in hair count. While it doesn’t specifically say in the study itself, I assume the hair count was per cm of hair in the frontoparietal and vertex areas of the scalp.
Can this really be true or are there other factors coming into play here? One significant thing that I noticed when reading the study was that no control group was used. A control group is a group that allows researchers to confirm that the results of the study are due to the independent variables, in this case being rosemary oil and minoxidil, and not extraneous variables. For instance, the natural shedding and growth cycle of hair, the fact that one of the side effects of Minoxidil is initial shedding, the fact that 2% minoxidil is commonly used for women while 5% is used for men.
While the study does show that rosemary oil has hair growth properties, one that seems to be equivalent to 2% minoxidil, more research is needed to confirm these findings.
A different study investigating the treatment of alopecia areata (a disease in which hair falls out in patches) showed that a 7-month long application of rosemary essential oil and other essential oils (thyme, lavender, and cedarwood) in a mixture of carrier oils (jojoba and grapeseed) was effective in the treatment of alopecia areata. [2] However the lack of any further studies makes it impossible to say whether rosemary actually caused the hair to grow.
So if you want to use rosemary oil to test this out for yourself, when can you expect to see results if you use rosemary oil for hair growth? Because of the natural hair growth cycle, any significant effects from rosemary oil can expect to be seen at the 6 month stage.
How does rosemary oil work?
There are a few components in rosemary that make it useful for hair growth.
Rosemary enhances blood flow
Rosemary contains 1-8 cineole which is believed to increase spasmolytic activity that then enhances micro-capillary perfusion, allowing hair to grow. [1]
Microcapillary perfusion is the flow of blood through the small blood vessels in the body (microcapillaries). These little microcapillaries are vital for the functioning of organs and tissues as it allows oxygen and nutrients to be delivered to cells. There are some studies that suggest that rosemary may have a positive effect on microcapillary perfusion. [3]
Rosemary is a great antioxidant
Rosemary is also a great antioxidant. Oxidative stress and free radicals caused by sun, UV light, chemicals, or hair treatments can damage hair and studies have shown that the antioxidant activity rosemary has can mitigate this stress and in this case may be beneficial for hair growth. [1]
Rosemary is an antimicrobial
Rosemary has antimicrobial properties, which means it can help to kill bacteria and other microorganisms on the skin and scalp. This can help to prevent dandruff and other scalp conditions that can interfere with healthy hair growth.
The specific chemical compounds in rosemary essential oil that may contribute to its potential benefits for hair growth are not fully understood. Rosemary essential oil contains a variety of chemical compounds, including monoterpenes, sesquiterpenes, and phenols. Some of these compounds, such as alpha-pinene, camphor, and 1,8-cineole, are thought to have potential health benefits.
Main components in rosemary oil and their benefits for head and scalp: [4, 5]
|
1-8 cineole |
18.0-23.9% |
Antimicrobial, spasmolytic action |
|
Borneol |
|
|
|
Camphor |
23.9-35.8% |
Antimicrobial, anti-cancer properties, relieves pain, promotes hair growth. |
|
Borneol acetate |
1.1-4/1% |
|
|
Alpha-Pinene |
4.5-14.4% |
Antimicrobial, , anti-cancer properties, promotes hair growth |
|
Beta-Pinene constitute |
2.1-3.3% |
|
|
Phenolic acids (rosmaric acid, caffeic acid, and salicylate) |
|
Antioxidant, anti-inflammatory, anti-allergic, antibacterial, DHT blocker |
Can Rosemary block DHT?
Some studies have suggested that rosemary may help to block the action of dihydrotestosterone (DHT), a hormone that plays a role in male pattern baldness and hair loss in both men and women.
The active compound in rosemary that is thought to have DHT-blocking properties is called rosmarinic acid. Rosmarinic acid is a type of polyphenol, a class of compounds that are found in plants and have a number of potential health benefits.
There is some evidence to suggest that rosmarinic acid may help to inhibit the activity of an enzyme called 5-alpha reductase, which converts testosterone into DHT. By blocking the action of this enzyme, rosmarinic acid may help to reduce the levels of DHT in the body and potentially prevent hair loss.
Rosemary oil vs Minoxidil
Both Minoxidil and rosemary oil can be used as a treatment to combat hair loss and promote hair health.
Most importantly, Minoxidil is the most proven over the counter option for hair regrowth while more studies need to be done to fully understand and confirm the effects rosemary has on hair growth.
People may choose rosemary oil instead of minoxidil as it is a more natural approach and does not come with the many side effects that minoxidil is associated with.
Ultimately, the decision on which product to use should be made in consultation with a healthcare provider, who can assess your individual needs and determine the most appropriate treatment for you.
Unless you have an allergic reaction to rosemary, rosemary oil is generally considered safe and effective when used correctly. However it is always a good idea to consult a doctor prior to using this essential oil.
Rosemary Oil and Blonde Hair
As I have blonde hair (naturally blonde with blonde colour treatment), one of the concerns I had was whether rosemary oil would darken my hair. I did not pay hundreds of dollars to lighten my hair for my hair to turn yellow or darker because of rosemary oil!
Rosemary essential oil is colourless before a carrier oil is mixed in. Whether rosemary oil will change the colour of your hair depends more on the carrier oil you choose to use if you are making this at home. For blonde hair, colourless hair oils are the best such as coconut oil or babassu oil.
Most store bought hair oils with rosemary oil in them are made up of the essential oil + carrier oil. Therefore if you are buying a rosemary hair oil from a store, just check the colour of the oil!
Rosemary oil vs Rosemary essential oil vs Rosemary Extract
Rosemary oil can refer to either an essential oil or a vegetable oil that is made from the leaves of the rosemary plant (Rosmarinus officinalis), or the extract..
Rosemary Essential Oil
An essential oil is a concentrated, liquid plant extract that is extracted from leaves, flowers, roots, bark, seeds, or peel of a plant.
Rosemary essential oil is made from the leaves and flowering tops of the rosemary plant (Rosmarinus officinalis). The oil is extracted through a process called steam distillation, which involves boiling the plant material in water to release the essential oils. Rosemary essential oil has a strong, woody, and slightly sweet aroma and is believed to have a variety of potential health benefits.
The quality of rosemary essential oil can vary depending on factors such as the type of rosemary plant used, the growing conditions, and the method of extraction. Therefore, it is important to choose a high-quality rosemary essential oil.
Rosemary Oil
Rosemary vegetable oil, on the other hand, is a type of oil that is made from the leaves of the rosemary plant and is used as a base for products such as soap and lotion, or for cooking. It is made through a process called pressing, which involves mechanically extracting the oil from the plant material. Rosemary vegetable oil is a pale yellow or greenish colour and has a strong, woody, and slightly sweet aroma.
Rosemary extract
Rosemary extract is created by soaking dried rosemary leaves in a solvent containing ethanol (or sometimes water) which separates the active ingredients from the plant matter. The solvent is removed, leaving the "oleoresin extract" behind. An oleoresin extract contains essential oil as well as the heavier resins, waxes, and oils also dissolved by the solvent. Because it is an oil-based extract, it is generally not soluble in water. Rosemary extract is usually dissolved in a solvent, such as alcohol or oil, in order to make it easier to use and to preserve the active compounds found in the plant. The extract can then be added to water-based products, such as shampoos or lotions, but it will remain suspended in the water rather than fully dissolving.
The table below summarises the similarities and differences between rosemary essential oil and rosemary (vegetable) oil. [6]
|
|
Rosemary Vegetable Oil |
Rosemary Essential Oil |
Rosemary Extract |
|
Extraction process |
Pressing |
Distillation |
Extraction |
|
Colour |
Pale yellow or green |
Clear or pale yellow |
Dark yellow to amber |
|
Aroma |
Strong, woody, sweet |
Strong, woody, sweet |
earthy |
|
Uses |
Skin and hair care |
Aromatherapy, natural remedies, and skin and hair care |
Health aid, as a tea or tonic, cooking, cosmetics (skin and hair) |
|
Application |
Can be used directly |
Highly concentrated - a carrier oil must be added |
Highly concentrated - if used for hair and skin care, a carrier oil or alcohol should be used. |
|
Potential benefits |
Astringent (tightens skin), antioxidant (from 1,8-cineole, camphor, and α-pinene) |
Stimulates scalp, promotes circulation, antioxidant |
Antibacterial, antioxidant (from mainly carnosic acid and rosmarinic acid) |
|
Main volatile compounds |
rosmarin, salvianol and muriatic acid. |
1,8 cineole (18.0-23.9%), camphor (23.9-35.8%), and α-pinene (4.5-14.4%), rosmarinic acid |
gallocatechin (26.4%), rosmarinic acid (18.0%), and luteolin-3-O-acetyl-O-glucuronide (14.2%) |
|
Solubility |
Insoluble in water |
Insoluble in water |
Insoluble in water. Soluble in water and ethanol |
Main active ingredients in each responsible for hair growth*:
|
Compound |
Benefit for hair growth |
Rosemary Vegetable Oil |
Rosemary Essential Oil |
Rosemary Extract |
Rosemary Water |
|
1,8 Cineole |
spasmolytic action |
✓ |
✓ (most) |
✓ |
Not significant amounts |
|
Camphor |
promotes hair growth |
✓ (3rd most) |
✓(most) |
✓ (2nd most) |
✓ (least) |
|
α-pinene |
promotes hair growth |
Not significant amounts |
✓ (most) |
✓ (2nd most) |
Not significant amounts |
|
rosmarinic acid |
DHT blocker |
✓ (3rd most) |
✓(least) |
✓ (2nd most) |
✓ (most) |
*The exact composition of each rosemary product is also influenced on how it is prepared, the concentration, and the type of plant used.
The concentration of 1,8 cineole, camphor, alpha-pinene, and rosmarinic acid can vary significantly between rosemary vegetable oil, rosemary essential oil, rosemary extract, and rosemary water.
Rosemary essential oil is likely to contain the highest concentration of monoterpenes (such as alpha-pinene and 1,8 cineole) and the lowest concentration of phenols (such as rosmarinic acid) compared to the other three types of rosemary products. This is because rosmarinic acid is a water-soluble compound, and is not present in significant quantities in the essential oil, which is extracted from the plant using steam distillation.
Rosemary vegetable oil is likely to contain a combination of monoterpenes and phenols, while rosemary extract and rosemary water are likely to contain a lower concentration of monoterpenes and a higher concentration of phenols compared to rosemary essential oil.
It is important to note that the concentration of these compounds can vary significantly depending on the source and method of production. It is always best to check the product label or contact the manufacturer for information on the specific content of these compounds in a particular product.
Which rosemary oil is best for hair growth?
Both rosemary vegetable oil and rosemary essential oil can help your hair grow, however rosemary essential oil contains higher concentrations of active compounds than rosemary oil. In addition to rosmarinic acid, rosemary essential oil contains a number of other active compounds, including carnosic acid, ursolic acid, and betulinic acid.
If you buy rosemary essential oil, you will have to add a carrier oil as rosemary essential oil is too potent to apply directly to your skin and can result in irritation.
If you buy rosemary vegetable oil, a carrier oil is already incorporated into the mixture.
So whether you make your own rosemary oil from essential oils or buy a ready to use mix, they both contain the active compounds necessary for hair growth. It then comes to personal preference and whether the carrier oil used in the ready-to-use hair oil is suitable for your hair type (porosity and colour).
Citations: