Rosemary dosage and safety
Pro Research Analysisby 
Searched over 200M research papers
Rosemary Dosage: Human and Animal Studies
Human Dosage Ranges and Effects
Clinical studies have tested rosemary extract in humans at daily doses ranging from 100 mg to 1,000 mg. In a randomized, double-blind trial, doses of 500 mg and 1,000 mg per day for three months significantly reduced symptoms of common mental disorders, with no reported side effects, indicating good safety at these levels for short-term use . Another study on skin quality used a supplement containing rosemary extract for 12 weeks, with a dosing schedule starting at six capsules per day and tapering to two capsules per day. The supplement was generally well tolerated, with only one participant discontinuing due to moderate gastrointestinal upset .
A study on cognitive function in older adults found that a low dose of 750 mg of dried rosemary leaf powder improved memory speed, while a high dose of 6,000 mg impaired cognitive performance, suggesting that moderate doses are safer and more effective for cognitive benefits .
Animal Studies: Acute and Chronic Safety
Acute toxicity studies in rats have shown that single oral doses of rosemary extract up to 2,000 mg/kg body weight are well tolerated, with no observed adverse effects, changes in behavior, or organ damage over a two-week period 110. Similar results were found in studies using polyherbal formulations containing rosemary, ashwagandha, and amla, with no toxicity observed at 2,000 mg/kg .
A reproductive and developmental toxicity study in rats found no adverse effects at dietary concentrations up to 5,000 mg/kg, establishing a no-observed-adverse-effect level (NOAEL) of 316–401 mg/kg body weight per day for general and reproductive toxicity. However, some reductions in thyroid hormone (T4) were noted in pups, though without clear clinical significance .
Regulatory and Food Additive Safety
Regulatory bodies have set acceptable daily intake (ADI) levels for rosemary extract when used as a food additive. The European Food Safety Authority (EFSA) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) have established a temporary ADI of 0–0.3 mg/kg body weight per day, based on the sum of carnosic acid and carnosol, the main active compounds in rosemary extract . Actual estimated exposures from food additives are generally well below this limit, even in children .
For use in animal feed, EFSA has determined that rosemary extract is safe at concentrations up to 300 mg/kg feed for dogs and 50 mg/kg feed for cats, though it can be a skin and eye irritant in its concentrated form .
Potential Adverse Effects and Precautions
While rosemary is generally considered safe for food and short-term supplement use, high or chronic doses may pose risks. Some studies have reported potential adverse effects on the liver, kidneys, and reproductive system at high doses or with long-term use, including changes in liver and kidney function markers and possible reproductive toxicity . Allergic reactions and dermatitis have also been reported in sensitive individuals 67.
Conclusion
Rosemary extract is considered safe for most people when used at moderate doses (up to 1,000 mg per day in humans) and as a food additive within regulatory limits. Animal studies support a high margin of safety for acute and short-term use. However, caution is advised with high or chronic doses due to potential risks to the liver, kidneys, and reproductive system, and individuals with allergies should be aware of possible skin reactions. Further research is needed to clarify the long-term safety profile of rosemary, especially at higher doses or with prolonged use 12345679+1 MORE.
Sources and full results
Most relevant research papers on this topic