What are the side effects of rosemary oil?

Author: Prof. Dakota Ledner  |  Last update: Thursday, June 26, 2025

Rosemary leaf is possibly safe for most people when taken as a medicine for up to 8 weeks. But taking undiluted rosemary oil or very large amounts of rosemary leaf is likely unsafe. Taking large amounts of rosemary can cause vomiting, sun sensitivity, and skin redness.

What are the side effects of rosemary oil on hair?

Rosemary oil is a powerful antioxidant and can be used to treat many skin conditions, such as eczema, psoriasis and acne. However it has also been known to cause damage to your scalp and follicles if used incorrectly. Rosemary oil can cause inflammation which can lead to hair loss in some cases.

Who should not use rosemary oil?

Because higher doses of rosemary may cause miscarriage, pregnant and nursing women should not take rosemary as a supplement. But it is safe to eat as a spice in food. People with high blood pressure, ulcers, Crohn's disease, or ulcerative colitis should not take rosemary.

Why is my hair falling out after rosemary oil?

There could be several reasons why your hair is falling out after using rosemary oil, including individual sensitivity, improper application, interaction with other hair products, or an existing underlying condition exacerbated by the oil's properties.

Is it OK to use rosemary oil everyday?

You can put rosemary oil in your hair every day. A recommended number of times that work for most people is 3 to 4 times a week. The high concentration of essential oils can sometimes disrupt the pH level of the skin which results in irritated skin.

What Happens to Your Body When You Drink Rosemary Tea Every Day

What happens if you leave rosemary oil in your hair for too long?

Yes, you can leave rosemary oil in your hair overnight to reap the benefits while getting some well-deserved rest. However, it is important not to leave directly-applied rosemary oil on the hair overnight, as this can cause irritation. Only ever use diluted rosemary oil or products infused with rosemary oil.

Does rosemary oil actually help hair growth?

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.

Can too much rosemary damage hair?

Rosemary oil is highly concentrated. Using too much of it may damage the hair follicles, causing hair loss instead of hair growth.

How long does it take for rosemary oil to reverse hair loss?

Clinical studies have shown that some people see results from using rosemary oil in just three months [1]. But it's more likely to take six months or longer. So if you decide to use rosemary oil, you'll need to be persistent and apply it diligently for at least a few months before you see the first signs of regrowth.

What is the best oil for hair growth scientifically proven?

Rosemary Oil: As mentioned previously, rosemary oil is the only oil that is clinically proven to have a significant effect on increasing hair growth, similar to that of minoxidil.

What not to mix with rosemary?

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with ROSEMARY. Rosemary might slow blood clotting. Taking rosemary along with medications that also slow blood clotting might increase the risk of bruising and bleeding.

What are the disadvantages of hair growth oil?

The Drawbacks of Using Oils for Hair Growth

"A word of caution: Some oils can cause dandruff and when exposed on the face from hair contact, cause acne," says Dr. Kormeili. Castor and coconut oils, for example, can clog your pores, and clogged pores can result in a zit.

Is rosemary oil bad for hormones?

The recorded data of the current study referred that the extract of rosemary leaves possesses anti-infertility and solid antioxidant activities and can be used as fertility increasing drug to control sexual hormones also spermatogenesis, preventing toxicity and its pathophysiological consequences.

What happens if you don't dilute rosemary oil?

Rosemary oil, like all essential oils, is naturally very potent. If applied onto the skin or hair without first being diluted, it can cause irritation that could end up being severe if left untreated.

Which brand has the best rosemary oil?

One of the best brands for rosemary oil in essential oil form, the Wishcare Rosemary Essential Oil is 100% pure and steam distilled. It works fantastic when combined with a carrier oil for helping with hair growth and is also great for using in diffusers.

How do I know if I'm allergic to rosemary oil?

The skin prick test is a common method used to diagnose rosemary allergies. During this test, a small amount of rosemary extract is applied to the skin using a tiny needle. If a raised bump or hive develops at the test site, it indicates an allergic reaction to rosemary.

Can I leave rosemary oil in my hair daily?

Yes — as long as it doesn't irritate your skin, there's no reason why you can't leave rosemary oil in your hair all day. If you have any irritation or sensitivity, reduce application time.

Can rosemary reverse GREY hair?

Not only that, rosemary oil is said to potentially reduce the appearance of grey hairs, as it has an effect on the pigmentation of hair.

How to tell if rosemary oil is working on hair?

Since there is a lack of evidence whether rosemary oil consistently works for hair growth it is hard to tell. However, if you do not notice any new hairs in three months time, you can discontinue using the oil and consult an online dermatologist to get adequate treatment.

What happens if I spray rosemary water on my hair everyday?

Can I spray rosemary water on my hair every day? Yes, you can spray rosemary water on your hair every day. Regular application can help improve hair health, reduce dandruff, and promote hair growth without causing significant side effects.

Will my hair fall out if I stop using minoxidil?

This medication must be used on a regular basis for your hair to regrow. It may take 2 to 4 months of regular use before you notice any improvement. It is important to continue to use this product to maintain regrowth of hair. Once you stop using it, the regrown hair will usually fall out within 3 months.

Does rosemary actually thicken hair?

Does Rosemary Oil Thicken Hair? The short answer is yes. There is some scientific evidence that rubbing rosemary oil into the scalp can help hair growth. One rosemary for hair growth study showed that rosemary oil was as effective as minoxidil at stimulating hair growth.

Will my hair fall out if I stop using rosemary oil?

While rosemary oil is generally considered safe and effective for promoting hair growth, there is a possibility of increased hair shedding or temporary hair loss after discontinuing its use, particularly if it was used for an extended period.

What is the best oil for hair loss?

Best Value

And another study found that the aromatherapeutic effects of rosemary oil (just smelling it while massaging it onto the scalp) helped patients with alopecia areata.

What are the side effects of minoxidil?

The most common side effects of topical minoxidil application are redness and irritation of the skin. Rarely, patients have reported headaches, palpitations, and dizziness. Oral minoxidil side effects include palpitations, dizziness, low blood pressure, chest pain, headaches, and swelling of the legs.

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