8 Rosemary Benefits: Dosage & Safety

Rosemary is an ancient herb that is commonly used today as both a food and medicine.

In traditional medicine, rosemary was specifically used for memory, pain relief, headaches, and as a stimulant for the nervous system.   

Modern research demonstrates that rosemary and its active phytochemicals may be beneficial for inflammation, heart health, hair growth, and as a food preservative.

In this article, we will review the health benefits of rosemary, its safety, and its history.  

What is Rosemary?

Rosemary is an aromatic plant that belongs to the Lamiaceae family, better known as the mint family. This herb is originally native to the Mediterranean region but is now globally grown and traded. 

Rosemary’s Latin name is Rosmarinus officinalis. 

The needle-like leaves are the most common part of the plant that is used. However, the woody branches that the leaves grow on also have health benefits 

Rosemary has a potent, stimulating odor that warms the body and supports circulation. Modern research supports traditional claims that rosemary has anti-inflammatory, cognitive-boosting, and hair growth effects.

A variety of these therapeutic health benefits of rosemary can be attributed to the multitude of active constituent compounds present, including:  

• Rosmarinic acid
• Caffeic acid
• Carnosic acid
• Oleanolic acid
• Camphor
• Ursolic acid
• Borneol 

Presently, rosemary is cultivated and traded globally, but it prefers a dry Mediterranean-like climate. 

Health Benefits of Rosemary:

Rosemary is a well-researched herb with a wide range of human clinical trials backing its health benefits. Many of its traditional uses are supported by modern science.

Below are the top researched-backed rosemary benefits for health.

1. May Have Cognitive Enhancing Effects 

Evidence shows that rosemary has promising effects on enhancing cognition.

Brain health is important for maintaining the ability to learn, think critically, solve problems, and store information. Keeping the brain healthy can prevent mood disorders and age-related neurodegenerative diseases, which can impact memory recall and cognition.

In a trial involving Japanese men, rosemary extract was able to improve fatigue, mood, and cognitive function. After 4 weeks of administration, the extract was also shown to increase energy levels and mental clarity in the subjects.

A 2012 study found that rosemary powder has a cognitive enhancing effect in elderly individuals. Testing various doses, the researchers found that a 750mg/day dose increased long-term memory recall. It should be noted that the high-dose group that took 6,000mg/day saw a decline in memory recall.

In a trial with university students, taking 500mg of rosemary twice daily for one month showed promise for increasing memory performance. The rosemary supplementation also reduced anxiety and depression and improved sleep.

A combination study involving rosemary, sage (Salvia officinalis), and lemon balm (Melissa officinalis) extract discovered that the extract improved delayed word recall in subjects under the age of 63.  

2. May Reduce Stress, Anxiety, & Depression 

Rosemary has promising potential as an herb for anxiety and depression, since it may work to relieve stress.

Anxiety and depression are considered mental health disorders. Both ailments affect behavior and mood and will often trigger other issues such as low energy, fatigue, and trouble sleeping.

Researchers found that rosemary and lavender (Lavandula angustifolia) essential oil sachets had the ability to decrease test-taking stress in nursing students. The reduction in stress was measured through scores of test anxiety, personal statements, and pulse rate. 

A trial involving university students discovered that rosemary supplementation reduced anxiety and depression and improved sleep scores. After 1 month of administration, the students’ anxiety scores improved by 18% while depression scores improved by 9%. The sleep scores improved by 14%. 

A recent 4-week intervention trial involving adults with mild depression found that rosemary extract significantly improved tension anxiety and fatigue upon waking. Participants also experienced an increase in mental energy. 8mg of rosemary extract was given to each subject every day.  

3. May Support Hair Growth

Both traditional and modern therapeutic practices have used rosemary for hair growth. 

Alopecia is a condition that results in hair loss. It impacts up to 50% of males, and 15% of females in the United States. Hair loss from alopecia can happen anywhere on the body and although there are promising therapies, there is no guaranteed treatment. 

In a comparative trial, rosemary oil was discovered to be just as effective as a pharmaceutical therapy, minoxidil 2%, in treating androgenetic alopecia. There was a comparable increase in hair growth in both groups, but there was less scalp itching in the rosemary oil group. 

A study involving patients with alopecia areata found that consistent daily application of an essential oil blend including, rosemary, thyme, cedarwood, and lavender mixed in carrier oil was able to support significant hair regrowth. 

In another combination trial, rosemary, thyme (Thymus vulgaris), and lavender essential oils significantly improved hair growth in participants with alopecia areata. Out of 20 subjects, 15 saw moderate to dense hair regrowth using the essential oil blend for 12 weeks. 

An animal study using rosemary leaf extract found that 2mg/day increased hair regrowth in mice with testosterone-induced androgenic alopecia. Researchers discovered that this effect happened because the extract inhibited certain hormones from binding to receptors.  

4. Anti-Inflammatory Properties

Research shows that rosemary helps to reduce inflammation.   

Inflammation is a healing response controlled and regulated by the immune system. Short-term or acute inflammation is necessary for the body to recover, however, chronic inflammation is known to lead to a number of health complications over time. 

A comparison study involving asthmatic patients found that Rosmarinus officinalis extract was able to reduce asthma symptoms significantly when compared to Platanus orientalis, or plane tree. The rosemary extract was able to reduce wheezing, coughing, and sputum production, while the plane tree extract only worked to reduce coughing and tightness in the chest. Researchers attributed these effects to the reduction of inflammation in the airway.

In an animal study, researchers discovered that the volatile oils in rosemary extract were able to reduce inflammation of the airway in mice with dust mite allergies.

Another animal study found that rosemary extract shows promise for reducing pro-inflammatory markers in mice with pleurisy. Researchers noted that these findings could be helpful for individuals with rheumatism and asthma.

In a study involving rats with pulmonary fibrosis, rosemary extract was able to reduce pro-inflammatory biomarkers. The extract was also able to reduce the fibrotic reaction that was exacerbated by the inflammation.  

5. May Support Heart Health

Clinical research has shown that rosemary benefits heart health.

Heart disease is an issue that some are born with, or it can develop from complications such as high blood pressure, diabetes, obesity, or poor diet. It’s one of the leading causes of death in the United States.

A 2014 study involving subjects at risk for cardiovascular disease found that meat cooked with rosemary was able to decrease oxidative stress and inflammatory markers, which are known to increase the risk of heart disease.

In an animal study, rats were fed rosemary extract after undergoing a heart attack. The extract improved the recovery rate by decreasing markers of oxidative stress and improving energy metabolism. 

Another animal trial involving mice with heart injury discovered that treatment with one of rosemary’s active constituents, Carnosic acid, in combination with Carvedilol (medication used for high blood pressure) lowered the rate of cardiotoxicity markers. These two therapies together also decreased pro-inflammatory and oxidative stress markers. 

6. Antioxidant Properties

The benefits of rosemary have been shown to include antioxidant effects.

In a trial where rosemary extract was consumed by participants at risk for heart disease, subjects saw a significant decrease in oxidative stress and inflammatory markers. These antioxidant and anti-inflammatory effects are known to lower the risk of heart disease. 

A combination animal study found that olive (Olea europaea) and rosemary extract have the ability to protect liver health. Researchers believe this effect is due to the extract’s antioxidant activity. 

Another animal study found that rosemary extract has the ability to decrease oxidative stress in rats that had just undergone a heart attack. Rats that were given the rosemary extract saw a vast improvement in recovery due to these antioxidant effects. 

7. May Help With Allergies

Research suggests that rosemary may be of the best herbs for allergies.

Rosemary contains a constituent known as rosmarinic acid, which has been shown to help with allergic rhinitis.

A research review found that rosmarinic acid can help to reduce inflammation and allergy symptoms.

A clinical trial looked at the effect of rosmarinic acid in people with seasonal allergies. The study participants were given either rosmarinic acid or a placebo. After 3 weeks, the rosmarinic acid group reported that they experienced fewer allergy symptoms.

Additionally, a lab-based study found that rosmarinic acid helped to reduce airway inflammation induced by house dust mites.

8. Other Benefits 

Other purported rosemary health benefits include: 

May Provide Pain Relief: Researchers found that the topical application of rosemary was able to significantly reduce pain levels in hemodialysis patients. 

Antidiabetic: In a study with Type 1 diabetic children, the administration of rosemary extract resulted in a reduction of diabetic markers. There was a significant difference between children who received rosemary extract and those that didn’t.   

Gastrointestinal Discomfort: The European Medicines Agency recommends rosemary for mild spasmolytic relief from gastrointestinal disorders. They suggest that it is also supportive of symptoms of dyspepsia. 

Food Preservative: A review of the active components in Rosmarinus officinalis points to the promising potential that rosemary can be used in food preservation due to this herb’s ability to prevent bacterial growth.

Rosemary Safety:

Safety Class: 1

Interaction Class: A 

Rosemary is “generally recognized as safe” (GRAS) by the U.S. Food and Drug Administration.

Rosemary is generally regarded as safe for most individuals to consume.

The European Medicines Agency notes that due to a lack of sufficient information, high-dose rosemary extracts should not be used by children and adolescents under the age of 18. Further, those that experience hypertension should proceed with caution when taking a rosemary-infused bath.

The Botanical Safety Handbook (2013) reported that some topical allergic reactions to rosemary have been reported and a patch test is recommended before applying topically.  

The European Food Safety Authority has concluded that rosemary extract is safe to consume when added to food and beverage.

Pregnancy & Lactation:

Traditional evidence claims that dried rosemary and rosemary tea are considered safe during pregnancy, but that essential oil and other concentrated extracts should be avoided.

Due to the lack of modern scientific research and an absence of sufficient data, experts do not recommend rosemary during pregnancy and lactation. 

How Much Rosemary Should I Take?

Standard dosing for rosemary is as follows:

Infusion: Add 1 cup of boiling water to 1 to 2 tsp. of dried herb and cover for 10 to 15 minutes. Drink 3x/day

Tincture (1:5): 1 – 2 ml, 3x/day 

Dietary Supplement (capsules): 1400mg, 2x/day

Topical: Use 3-6 drops of essential oil per 1 teaspoon carrier oil (jojoba, coconut, grapeseed, etc.) 

Bath: Add 3-6 drops of essential oil into a full bath or foot bath

Hungary Water: Pour 1 gallon of spirits (apple cider vinegar, witch hazel, or vodka) over 1 1/2 lb. of fresh rosemary tops in full bloom. Allow to infuse for 4 days, strain out the herbs, then distill.

Rosemary Water (for hair rinse): Add 1 tsp of dried rosemary to every 1 cup of water. Bring to a boil, then simmer for 15 minutes. Allow to sit for 30 mins and strain out the herb. Rinse your hair with the rosemary water after shampooing to stimulate growth. 

Sustainability:

Rosemary is not on the United Plant Saver’s “at-risk” list and is generally considered a sustainable, safe plant.

Naming & Taxonomy:

Rosemary’s scientific name is Rosmarinus officinalis. It is a perennial plant and part of the mint family, Lamiaceae.

The name “rosemary” comes from the Latin words “ros” and “marinus” meaning “dew of the sea.” This nomenclature comes from the fact that the small, pale blue rosemary blossoms on the high cliffs above the Mediterranean sea look like dew on the green leaves. 

The rosemary plant is considered a shrub and produces long woody branches that contain dense, pungent, needle-like leaves. This herb loves to grow in dry regions where the soil is dry and there is lots of sunshine. 

The leaves and branches have a drying, stimulating flavor and are both considered the medicinal and cosmetic sections of the plant. The needle leaves are the edible portion of the plant commonly used in cuisines. 

Other common names of rosemary include rosmarin (French and German), rosmarino (Italian), polar plant, compass plant, compass weed, and Incensier (Old French).  

Although the plant will grow in both dry and loamy soil, it does not like very humid or very cold areas. The British Pharmacopeoia mentions that oil made from the flowering tips creates a superior oil than oil made from branches and leaves, however, most oil is made from the latter. 

Spain is currently one of the largest producers of rosemary oil as it exports rosemary all over the world. 

History & Traditional Use:

Rosemary has a rich history of medicinal, culinary, and cosmetic use dating back to ancient Greece, Rome, and Egypt. It was also used in religious ceremonies as incense, hence the Old French name for rosemary, Incensier.  

In ancient Egypt, Egyptians would use cream mixed with rosemary oil topically to protect themselves from the heat and sun. Evidence shows that rosemary made an appearance in China around 220BC. Around 40-90 BC, Dioscorides mentions rosemary as being helpful for fatigue.

Rosemary is a symbol for lovers and has historically been used as a wreath in weddings, funerals, festivals, and religious ceremonies.

In Spain, it was believed that the rosemary bush gave shelter to the Virgin Mary when she was fleeing to Egypt. Italians and Spaniards both believe it to be a plant of protection against evil spirits. 

In French hospitals, rosemary and juniper twigs are burned to clear the air and prevent infection. This ritual is still used in France to this day. 

A special, topical recipe made from rosemary was used to revive circulation in paralyzed limbs. The preparation was called Hungary Water due to its curing effect on the Queen of Hungary in the mid-1300s. Hungary water was also used as a perfume. 

Rosemary vs. Other Herbs:

Rosemary is often compared with other herbs. We have put together helpful articles going over the most common comparisons.

•Rosemary vs. Lavender

Conclusion:

Rosemary is a highly beneficial herb for medicine, food, and cosmetics. It offers a wide range of support for issues such as hair loss, heart health, and brain health. 

It is supportive of various inflammatory problems, including asthma and allergies.

In addition to these effects, rosemary has the powerful ability to enhance cognition and preserve food.   

As always, it is important to get in touch with a healthcare professional should you decide you would like to make any adjustments to your diet or add a new supplement.