Growth Market: How Rosemary Oil May Help Your Hair

The key to growing longer and healthier hair may come down to seasoning.

Using rosemary oil for hair growth exploded as a TikTok trend over the past year. Nearly a billion people on the social media app have watched hair-flipping testimonials on the benefits of the extract.

So, are those TikTokers onto something or should the savory herb be left as a dinner seasoning? Let’s comb through what’s fact or fiction with dermatologist Shilpi Khetarpal, MD.

Can rosemary oil help regrow hair?

The answer appears to be yes — and there’s some scientific evidence behind it.

Researchers found rosemary oil to be as effective at encouraging hair regrowth as minoxidil, a medication better known as Rogaine®, says Dr. Khetarpal. The small-scale study in 2015 focused on people with androgenic alopecia (male pattern baldness or female pattern baldness).

Using rosemary oil instead of minoxidil also led to fewer issues with itchy scalp at the three-month and six-month check-ins.

“The bottom line is, yes, it does seem to work,” says Dr. Khetarpal. “The study really prompted people to look at rosemary oil for hair growth. It became much more common in over-the-counter products after that, too.”

The limited 2015 study built on findings from 2013 and 2010 that hinted at rosemary’s potential to combat hair loss.

What makes rosemary oil effective for hair growth?

So, why does rosemary oil sometimes act like Miracle-Gro® when rubbed onto your scalp as a highly concentrated extract? Much of the credit goes to carnosic acid, a phenolic chemical compound in the plant.

Carnosic acid carries anti-inflammatory and antioxidant properties that can help rejuvenate damaged nerves and tissue in your body. Applying it to your scalp creates an environment where your hair can thrive.

“If you increase blood flow to the scalp, you give your hair the nutrients it needs to shed less, grow more and just be a bit healthier,” explains Dr. Khetarpal.

Other benefits of rosemary oil

Aside from promoting a hair growth spurt, rosemary oil has been linked to hair benefits such as:

• Dandruff control. Rosemary oil’s ability to limit skin inflammation also may work to reduce dandruff (seborrheic dermatitis) in some cases. “It helps calm things down on your scalp, which certainly can assist with dandruff,” says Dr. Khetarpal.
• Limiting premature graying. There’s some evidence that rosemary can help reduce stress, which has been shown to turn hair gray. “It’s a potential benefit, but more studies need to be done to determine its effect,” she adds.

How to use rosemary oil in your hair care routine

If you want to give rosemary oil a try to grow a thicker head of hair, Dr. Khetarpal offers these six tips and recommendations:

1. Focus on your scalp. Putting a coat of rosemary oil on your hair isn’t going to do anything aside from giving you a greasy look. “You want to apply it to the scalp as a treatment,” instructs Dr. Khetarpal. “Really focus on working it in.”
2. Give rosemary oil time to work. Let the rosemary oil sit and do its thing for at least a few hours. Dr. Khetarpal suggests using rosemary oil at night and then washing your hair in the morning.
3. Start slow. Try rosemary oil on a small area of your scalp before coating your whole head with it. “That’s a good way to test to see if it causes a reaction on your skin,” says Dr. Khetarpal.
4. No added fragrances. Products with added fragrance may diminish the effectiveness of the rosemary oil and increase the chance of skin irritation. “Try to find something that’s 100% rosemary oil,” she says.
5. A little goes a long way. A few drops of rosemary oil may be all it takes for an application. It can be added to your shampoo or conditioner, too.
6. Be patient. One use of rosemary oil isn’t going to give you a bushy head of hair. “You’re going to need to use it two or three times a week for six months to see meaningful improvement,” notes Dr. Khetarpal. “Stay consistent and give it time.”

Does your hair type make a difference?

Coarse hair may be better able to handle an application of rosemary oil. But people with finer hair might find that using the product makes their locks look greasy or weighed down.

“Everyone can use rosemary oil, but you might need to modify how often you use it depending on your hair type,” suggests Dr. Khetarpal. “Some people might be able to use it daily. Others may see that one or twice a week works best.”

Are there side effects to using rosemary oil?

Although considered relatively safe to use, rosemary oil isn’t recommended if you’re pregnant or breastfeeding (chestfeeding). Warning labels on some 100% rosemary products warn that use could affect the fetus or lead to a miscarriage.

Final thoughts

Rosemary oil may be able to help if you’re dealing with hair loss. But Dr. Khetarpal cautions against expecting dramatic results.

“You want to be realistic,” she says. “If you’ve had hair loss for over 20 years, don’t expect it to work wonders. It might help a bit, particularly if your hair loss is just starting, but the extent of the improvement is variable. There are no guarantees.”