Rosemary is rich in antioxidant, antimicrobial, and anti-inflammatory constituents. It may offer several health advantages, such as helping to lower blood sugar and supporting cognitive health, among other effects.
Beyond its culinary and fragrant uses, rosemary has long been utilized in traditional herbal and Ayurvedic practices (1).
The rosemary shrub (Rosmarinus officinalis) originates from the Mediterranean region and parts of South America. It belongs to the Lamiaceae family, which also includes mint, oregano, lemon balm, and basil (2).
Many people appreciate rosemary tea for its flavor, scent, and potential health perks.
Below are six possible health benefits and uses of rosemary tea, along with potential drug interactions and a simple recipe for brewing it.
1. Rich in antioxidant, antimicrobial, and anti-inflammatory constituents
Antioxidants are substances that help guard your body against oxidative stress and inflammation, which are linked to chronic conditions like cancer, cardiovascular disease, and type 2 diabetes (3).
They occur in many plant-based foods, including fruits, vegetables, and herbs such as rosemary. Rosemary tea also carries constituents that may exert anti-inflammatory and antimicrobial effects.
The antioxidant and anti-inflammatory properties of rosemary are mainly credited to polyphenols such as rosmarinic acid and carnosic acid (4, 5).
Because of its antioxidant action, rosmarinic acid is frequently used as a natural preservative to extend the shelf life of perishable foods (6, 7).
Compounds in rosemary tea may also have antimicrobial qualities that could help combat infections. Rosemary leaves are used in traditional remedies for their antibacterial and wound-healing properties (6, 8, 9).
Research has also explored the effects of rosmarinic and carnosic acids on cancer; studies indicate these compounds may have antitumor activity and can slow the proliferation of leukemia, breast, and prostate cancer cells (10, 11, 12).
Summary: Rosemary tea provides compounds demonstrated to have antioxidant, anti-inflammatory, and antimicrobial actions. The most researched constituents are rosmarinic acid and carnosic acid.
2. May help reduce blood sugar
If left unmanaged, elevated blood sugar can harm your eyes, heart, kidneys, and nervous system. Proper blood sugar control is therefore essential for people with diabetes (13).
Research suggests that constituents in rosemary may help lower blood sugar, indicating potential for supporting glucose management in people with diabetes.
Although direct studies on rosemary tea are limited, in vitro and animal research on rosemary itself shows that carnosic acid and rosmarinic acid exhibit insulin-like actions on glucose metabolism.
Some studies report these compounds can enhance glucose uptake into muscle cells, thereby reducing blood sugar (14, 15, 16, 17).
Summary: Rosemary tea contains constituents that might reduce elevated blood sugar by acting like insulin and enhancing glucose uptake into muscle tissue.
3. May enhance mood and memory
Occasional stress and anxiety are normal experiences.
While specific research on rosemary tea is limited, evidence indicates that ingesting or inhaling rosemary compounds may help improve mood and memory.
One trial showed that taking 500 mg of oral rosemary twice daily for one month significantly reduced anxiety and improved memory and sleep quality among college students compared with placebo (18).
In another 2-month trial of 66 industrial workers, those who drank 2 teaspoons (4 grams) of rosemary in 2/3 cup (150 ml) of water daily reported feeling notably less job burnout than those who consumed nothing (19).
Even simply inhaling rosemary seems beneficial. A study of 20 healthy young adults found that sniffing rosemary aroma for 4–10 minutes before a cognitive test boosted concentration, task performance, and mood (20).
Another study in 20 healthy adults reported that inhaling rosemary oil increased brain activity and improved mood; participants showed rises in activity level, blood pressure, heart rate, and breathing rate after exposure (21).
Rosemary extract might enhance mood by encouraging a healthier gut microbiome balance and by lowering inflammation in the hippocampus—the brain region involved in emotions, learning, and memory (22).
Summary: Both consuming and inhaling rosemary compounds have been linked to reduced anxiety, improved mood, and better concentration and memory. Smelling or drinking rosemary may provide these effects, though more research is warranted.
4. May support cognitive health
Some laboratory and animal studies indicate that rosemary constituents may help preserve brain health by preventing neuronal death (23).
Animal data suggest rosemary might even aid recovery from conditions that can damage the brain, such as stroke (24).
Other studies propose that rosemary could protect against age-related cognitive decline and possibly offer defense against neurodegenerative conditions like Alzheimer’s disease (23, 25).
Summary: Compounds in rosemary tea may safeguard brain health, potentially protecting against injury and the impairments associated with aging and neurodegenerative disorders.
5. May protect eye health and vision
Although direct studies on rosemary tea and eye health are sparse, evidence suggests certain rosemary constituents may benefit the eyes.
Animal research indicates that combining rosemary extract with other oral therapies can slow the progression of age-related eye conditions (AREDs) (26, 27).
One study assessed adding rosemary extract to standard treatments like zinc oxide and other AREDs antioxidant mixes, finding it helped retard age-related macular degeneration (AMD), a common vision-impairing condition (28).
Additional animal and experimental work shows rosmarinic acid may delay cataract formation—the progressive clouding of the eye leading to vision loss—and lessen cataract severity (29).
Keep in mind most research on rosemary and eye health has used concentrated extracts, making it unclear what effect drinking rosemary tea would have and how much would be needed to achieve similar benefits.
Summary: Rosemary tea may include compounds that help protect vision with age, potentially slowing the progression and severity of conditions like cataracts and age-related macular degeneration.
6. Other possible benefits and applications
Rosemary has been explored for a variety of additional uses.
Other potential advantages of rosemary tea’s components include:
- May support heart health. An animal study found rosemary extract lowered the risk of heart failure after a heart attack (30).
- May aid digestion. Rosemary extract is sometimes used for indigestion, though clinical evidence is limited. Rosemary may support digestion by promoting a balanced gut microbiome and reducing inflammation (31, 32).
- May assist weight management. One animal study reported rosemary prevented weight gain in rats, even on a high-fat diet (33).
- May encourage hair growth. Anecdotally, some people use homemade rosemary tea as a hair rinse to promote growth, though robust evidence is lacking. Some studies suggest rosemary oil or extract applied to the scalp can reduce hair loss (34, 35).
Although these findings are promising, more human research is needed to determine what benefits drinking rosemary tea might deliver.
Summary: While preliminary evidence exists, rosemary tea may contain compounds that support cardiovascular and digestive health, aid weight control, and potentially address hair loss. More research is required.
Potential drug interactions
As with many herbs, some individuals should be cautious when consuming rosemary tea because of possible interactions with medications.
Medications with a higher likelihood of interacting adversely with rosemary include (36):
- anticoagulants (blood thinners)
- ACE inhibitors (for high blood pressure)
- diuretics (medications that increase urine output)
- lithium (used to treat bipolar disorder and other conditions)
Rosemary can produce effects similar to those medications, such as increasing urination, affecting blood clotting, and lowering blood pressure. For people taking lithium, rosemary’s diuretic action could cause lithium to accumulate to toxic levels.
If you use any of these medications—or others with related effects—consult your healthcare provider before adding rosemary tea to your routine.
Summary: Rosemary may have effects similar to certain drugs used to treat high blood pressure, promote urination, and affect circulation. If you take medications, talk with your healthcare professional before adding rosemary tea to your diet.
How to brew rosemary tea
Making rosemary tea at home is simple and requires only two ingredients: water and rosemary.
To prepare rosemary tea:
- Bring 10 ounces (295 ml) of water to a boil.
- Add 1 teaspoon of loose rosemary leaves to the hot water. Alternatively, place the leaves in a tea infuser and steep for 5–10 minutes, depending on how strong you prefer the flavor.
- Strain out the rosemary leaves using a fine mesh strainer or remove the leaves from the infuser. Discard the used leaves.
- Pour the rosemary tea into a cup and enjoy. If desired, sweeten with sugar, honey, or agave syrup.
Summary: Brewing rosemary tea at home lets you control its strength and ingredients. A cup can be made with just rosemary and hot water, using a stovetop or microwave.
Bottom line
Rosemary tea has several notable potential health benefits.
Drinking the tea—or even inhaling its scent—may support mood, brain function, and eye health, and could help prevent oxidative damage associated with many chronic diseases.
However, be mindful of possible interactions with certain medications.
Rosemary tea is easy to make at home with two ingredients and can fit into a healthy, balanced dietary pattern.
Keep in mind that many studies referenced here used rosemary extracts or essential oils, so it’s uncertain whether the tea will provide the same level of benefit.
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