Rosemary: Benefits, Uses, and Side Effects

by John Staughton (BASc, BFA) last updated - Medically reviewed by Emily Borth(MS, RDN)

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Rosemary is an herb that helps improve gut health, boost memory, improve mood, and lower the risk of cancer. It also helps to reduce inflammation, relieve pain, and protect the immune system. Moreover, rosemary can help protect against macular degeneration, stimulate circulation, detoxify the body, and heal many skin conditions.

This herb is considered to be sacred by ancient Romans, Greeks, Egyptians, as well as Hebrews and is particularly prevalent in Italian cultural cuisine. It is also known as ‘Dew of the Sea’ or ‘Old man’.

What is Rosemary?

Rosemary is a fragrant, woody herb native to the Mediterranean region. Its scientific name is Rosmarinus officinalis and it belongs to the Lamiaceae family, with other herbs, such as thyme, oregano, lavender, and basil. It has fine needle-like leaves with a silver touch and pink, purple, white, or blue flowers.

Rosemary has a warm, bitter, and astringent taste. Unlike many other herbs that lose their potency when dried, rosemary retains its taste even in the dried form. It gives a wonderful flavor and aroma to soups, sauces, stews, and chicken roasts.

Rosemary is rich in nutrients that help boost your immunity, reduce muscle pain, and improve your memory. Many people also use it for hair growth. It is available in many forms from fresh and dried to powdered forms for cooking. Rosemary tea, extracts, and essential oil are also used for these benefits.

Nutrition Facts

Rosemary, fresh
Serving Size :
Water [g]67.77
Energy [kcal]131
Energy [kJ]548
Protein [g]3.31
Total lipid (fat) [g]5.86
Ash [g]2.35
Carbohydrate, by difference [g]20.7
Fiber, total dietary [g]14.1
Calcium, Ca [mg]317
Iron, Fe [mg]6.65
Magnesium, Mg [mg]91
Phosphorus, P [mg]66
Potassium, K [mg]668
Sodium, Na [mg]26
Zinc, Zn [mg]0.93
Copper, Cu [mg]0.3
Manganese, Mn [mg]0.96
Vitamin C, total ascorbic acid [mg]21.8
Thiamin [mg]0.04
Riboflavin [mg]0.15
Niacin [mg]0.91
Pantothenic acid [mg]0.8
Vitamin B-6 [mg]0.34
Folate, total [µg]109
Folate, food [µg]109
Folate, DFE [µg]109
Vitamin A, RAE [µg]146
Vitamin A, IU [IU]2924
Fatty acids, total saturated [g]2.84
10:0 [g]0.02
12:0 [g]0.01
14:0 [g]0.12
16:0 [g]1.92
18:0 [g]0.23
Fatty acids, total monounsaturated [g]1.16
16:1 [g]0.07
18:1 [g]1.02
20:1 [g]0.05
Fatty acids, total polyunsaturated [g]0.9
18:2 [g]0.45
18:3 [g]0.41
Phytosterols [mg]44
Tryptophan [g]0.05
Threonine [g]0.14
Isoleucine [g]0.14
Leucine [g]0.25
Lysine [g]0.14
Methionine [g]0.05
Cystine [g]0.04
Phenylalanine [g]0.17
Tyrosine [g]0.1
Valine [g]0.17
Arginine [g]0.15
Histidine [g]0.07
Alanine [g]0.17
Aspartic acid [g]0.39
Glutamic acid [g]0.36
Glycine [g]0.16
Proline [g]0.14
Serine [g]0.13
Sources include : USDA

Rosemary Nutrition

According to USDA, fresh rosemary has a very high reserve of vitamins such as vitamin A, vitamin C, vitamin B6, thiamin, and folate. It contains minerals like magnesium, calcium, and iron. Moreover, it has abundant antioxidants in the form of phenolic compounds like diterpene, carnosol, and rosmarinic acid. The essential oils in it contain powerful ingredients such as cineol, camphene, borneol, bornyl acetate, α-terpineol, and α-pinene.

Aside from the nutrients mentioned above, the herb contains dietary fiber. It is low in cholesterol and sodium but high in saturated fats.

Health Benefits of Rosemary

The top health benefits of rosemary include:

Maintains Gut Health

One study showed that in test subjects with colitis, treatment with rosemary extract was effective to reduce colon tissue lesions and colitis. This, in turn, helps maintain gut health and fight gut diseases like irritable bowel syndrome (IBS) and colitis.

Rosemary has traditionally been used as a natural remedy for upset stomach, constipation, gas, bloating as it helps in relaxing the muscles of the intestine. Adding it to your diet can help you regulate your bowel movements and your gastrointestinal system.

Hair Growth

Rosemary oil helps to promote hair growth, prevent baldness, slow graying, and treat dandruff.

A comparative study published in 2015 shows that rosemary oil is effective in treating alopecia by boosting hair growth. At six months, a significant increase in hair count was noted for the group treated with rosemary oil. It also promotes healing by increasing microcirculation of the scalp and decreases hair loss after shampooing.

To know more, check out our guide on the Benefits of Rosemary Oil for Hair and How to Use it.


Carnosol and carnosic acids are two powerful antioxidants and anti-inflammatory compounds found in rosemary. These compounds have been linked to reducing inflammation of muscles, blood vessels, and joints. This makes it an effective treatment and prevention of many diseases, including blood pressure, gout, arthritis, and injuries sustained during physical exertion or surgery. It is effective in oral or topical form. Furthermore, the reduction in inflammation in the cardiovascular system can help boost heart health and prevent atherosclerosis.

Fresh rosemary herbs on a wooden tray

Rosemary has a warm, bitter, and astringent taste. Photo Credit: Shutterstock

Enhances Brain Function

One of the earliest documented uses of rosemary was as a cognitive stimulant.

It helped improve memory performance and quality. It is also known to boost alertness, intelligence, and focus. One possible mechanism for this action is that rosemary extract enhances the synthesis of nerve growth factor which is vital for nerve tissue.

As per a research study, rosemary prevents beta-amyloid plaques and suppresses acetylcholinesterase (AChE) activities. These actions are associated with the symptoms of Alzheimer’s, ataxia, and dementia. It has also been linked to stimulating cognition in the elderly as well as those suffering from other acute cognitive disorders.

The research titled “Brain Food for Alzheimer-Free Ageing: Focus on Herbal Medicines” suggests that rosemary is one of the best foods you can include in your diet to gain neuroprotective benefits.

The carnosic acid in rosemary has neuroprotective properties. A 2016 study suggests that it helps to reduce oxidative stress and overstimulation in nerve cells, ultimately protecting the nervous system.

There is also evidence showing that rosemary protects certain parts of the brain from tissue damage such as ischemic injury, heals nervous tissue, and reduces blood clots.

Reduce Liver Damage

Rosemary has been used for its protective effect on the liver in traditional medicine.

A 2015 animal study published in the Saudi Journal of Biological Sciences revealed that extracts of the leaves of rosemary and olive helped in reducing liver cirrhosis, likely due to their antioxidant activities.

Relieves Stress

Rosemary may have a calming effect on those who suffer from chronic anxiety and depression.

A study conducted on the anti-depressant effects of rosemary concluded that the herb is effective in improving symptoms of depression. These anti-depressant effects were observed even with repeated administration two weeks later. Furthermore, it may also reduce cortisol (the stress hormone) levels, which helps ease tension in the body.

Balances Hormone

Carnosol in rosemary decreases androgen receptor expression and also disrupts estrogen receptors in cancer cells. It also lowers the release of DHT (dihydrotestosterone) hormone, which helps improve prostate health and enhance hair growth.

Anticancer Potential

The Nutrition and Cancer journal has published a study in 2015, which suggests that rosemary extract is very helpful in cancer therapy.

Carnosol, rosmarinic acid, carnosic acid, and other rosemary extracts have antioxidant, anti-inflammatory, antiproliferative, and anticancer properties. They selectively kill cancer cells. It has shown promising results in the treatment of various cancers including colon, blood, breast, prostate, ovarian, cervical, liver, lung, bladder, and pancreatic cancer.

Skin Care

The antioxidants in the essential oils of rosemary help improve skin health. It has a potent anti-aging effect and helps heal blemishes and increase the natural shine. Also, its extracts with citrus supplements prevent skin against UV light damage, much better than the supplements alone.

In a research study on the effects of rosemary extracts on skin damage, Dr. Alice L. Pérez Sánchez states that the herb actually helps protect you against UV-induced damage through its antioxidant effects.

Macular Degeneration

The presence of carnosic acid in rosemary helps to prevent age-related macular degeneration, which affects the outer retina of the eye.

Limits Weight Gain

Rosemary herbal extracts exert anti-inflammatory and anti-hyperglycemic effects and promote weight loss. Treatment with rosemary extract resulted in significant weight loss and increased fecal excretion of lipids.

According to another study, carnosic acid-rich rosemary can be used as a preventive treatment for metabolic disorders.

Antibacterial & Antimicrobial

Rosemary is specifically powerful against bacterial infections. It is linked to preventing staph infections, which are highly contagious and can cause lethal boils and blisters. It also eradicates various gram-negative and gram-positive bacteria completely.

Due to its antibacterial qualities, rosemary intake has been shown to prevent the growth of H. pylori bacteria, a dangerous pathogen that is associated with gastritis, stomach ulcers, and some cancers.

Boosts Immunity

The active components in rosemary are antioxidant, anti-inflammatory, and anti-carcinogenic in nature. This represents a three-pronged attack against many different diseases and pathogens that could threaten the immune system or damage the integrity of the body.

Rosemary contains a significant amount of antioxidants including rosmarinic acid, caffeic acid, betulin acid, and carnosol. Antioxidants in rosemary make a secondary line of defense behind the body’s own immune system.

Other Benefits

Other benefits of rosemary include:

Prevents Blood Clot

Due to its abundant antioxidant profile, rosemary has an anti-thrombotic effect and helps prevent blood clots.

Freshens Breath

As a natural antibacterial agent, rosemary works as a wonderful breath freshener that improves your oral health. One study showed that an herbal mouthwash containing rosemary and other herbs was as effective as chlorhexidine in the treatment of gingivitis.

Steep the leaves in a glass of hot water and then gargle or swish the water in your mouth to eliminate bacteria, and you will have naturally fresh and clean breath all night!

Stimulates Blood Flow

Research published in the African Journal of Traditional, Complementary and Alternative Medicine showed that hematological parameters improved after treatment with rosemary extract as well as lipid peroxidation levels. Rosemary acts as a stimulant for the body and boosts the production of red blood cells and blood flow.

Relieves Pain

As an analgesic substance, rosemary is topically applied to the affected area to soothe the pain. When consumed orally, it acts as a pain reliever potentially helping with headaches, migraines, menstrual and stomach cramps, as well as kidney pain.

Detoxifies the Body

Rosemary is slightly diuretic in nature, meaning that it can help flush out toxins efficiently during urination. Furthermore, by increasing the rate at which water leaves the body, it can also help push out pathogens, salts, toxins, and even excess fat when consumed regularly. Rosemary has also been shown to have hepatoprotective effects; protecting the liver so it can do its job of detoxifying the body.

Increase Movement

Cineole in rosemary oil, taken either orally or via inhalation, boosts body activities by enhancing locomotion, according to a study.

How to Use Rosemary?

Rosemary comes in various forms like fresh leaves, dried leaves, oil, and extracts. Mentioned below are some of the ways to use it.

Rosemary Butter

Rosemary leaves can be used to flavor the butter that you use for steak, pasta or baked potatoes. Just chop the leaves finely and mix them with the butter.


You can also add this herb in soups to give them an extravagant flavoring. Add a few fresh or dried leaves while cooking and you will have a perfect aromatic soup.

Rosemary Salt

You can make rosemary flavored salt. Just add leaves from on stem in about 3 cups of salt and mix properly. Let the mixture sit for 15 days and you will be able to use it.

Rosemary-infused Olive Oil

Bring 2 cups of olive oil to a slight simmer and then remove it from heat. Put 3 – 4 rosemary sprigs into a clean airtight jar and pour the olive oil in it. You can use the oil for cooking in a week.

Side Effects

Although the plant is classified as safe by the FDA even at higher concentrations, its long-term excessive use has side effects like:

  • Vomiting
  • Skin irritation
  • Itchy scalp in bald patients
  • Increase blood glucose level in diabetics
  • Induce convulsions like epilepsy
  • Muscle spasms
  • Coma

Other risks include:

  • Pulmonary Edema: There is some evidence that rosemary leaves in excess quantity can cause pulmonary edema or fluid accumulation in the lungs. Rosemary may interact with diuretic medications often prescribed for this condition, therefore it is recommended you avoid taking rosemary If you take diuretic medications for this or any other reason. It is always best to check with your doctor.
  • Reduce Fertility: Long-term high consumption may lead to a decrease in sperm count, density, and mobility in men. In pregnant women, it may lead to miscarriage and abortion.
  • Drug Interactions: It may interact negatively with certain drugs like Warfarin (anticoagulant), Lithium (manic depression), Lasix (diuretic), and others. Be sure and check with your doctor or pharmacist before starting any new herbal supplements.

Note: If you are allergic to other members of the mint family, you may experience discomfort if you consume or apply rosemary or its oil, but the reactions are typically mild. Protection Status
About the Author

John Staughton is a traveling writer, editor, publisher and photographer with English and Integrative Biology degrees from the University of Illinois in Champaign-Urbana (USA). He co-founded the literary journal, Sheriff Nottingham, and now serves as the Content Director for Stain’d Arts, a non-profit based in Denver, Colorado. On a perpetual journey towards the idea of home, he uses words to educate, inspire, uplift and evolve.

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