Rosemary, a fragrant herb from the Mediterranean, is commonly used in cooking and traditional medicine. It has long been linked with mental clarity and memory, with ancient scholars using it to aid concentration. Recent studies suggest that rosemary may support brain health by improving memory, reducing anxiety, and potentially protecting against conditions like Alzheimer's disease. Inhaling its scent has been shown to enhance performance on memory-related tasks compared to being in an unscented environment. The brain benefits of rosemary come from several mechanisms. It can improve blood flow, which may help deliver more oxygen and nutrients to the brain. Its calming properties might ease anxiety and improve sleep. Rosemary also contains compounds like 1,8-cineole, which can help maintain acetylcholine levels—important for memory and learning. Additionally, its high antioxidant content helps protect brain cells from oxidative stress, a factor in cognitive decline. One of the most powerful compounds in rosemary is carnosic acid, known for its antioxidant and anti-inflammatory properties. In 2025, scientists developed a stable version of this compound called diAcCA, which showed promising results in pre-clinical studies. DiAcCA improved memory, increased brain connections, and reduced harmful proteins linked to Alzheimer's disease, like amyloid-beta and tau. It activates only in inflamed brain areas, potentially reducing side effects. Studies in mice showed no toxicity and significant cognitive improvements, raising hopes for future human trials. Beyond brain health, rosemary has been used traditionally for digestion, reducing bloating, and easing inflammation. Compounds like rosmarinic acid and ursolic acid are known to have anti-inflammatory effects throughout the body. Rosemary may also help with skin conditions, such as acne and eczema, and carnosic acid may offer anti-ageing benefits by protecting the skin from sun damage. Rosemary oil has antimicrobial properties, making it useful in food preservation and potentially in pharmaceuticals by inhibiting bacteria and fungi. Rosemary is generally safe when used in food, teas, or aromatherapy. However, concentrated forms or extracts can be risky, causing issues like vomiting or, in rare cases, seizures in people with epilepsy. Pregnant individuals should avoid high doses due to a possible risk of stimulating uterine contractions. Rosemary may also interact with certain medications, such as blood thinners, so it's best to consult a healthcare provider before using large amounts in supplement form.