The herb rosemary has been used as a food spice and as a medicine since ancient times. Traditional medicinal uses of rosemary leaf preparations taken internally include digestive distress, headaches, and anxiety. The fragrance of rosemary leaf has been said to enhance memory. Rosemary oil was applied to the skin to treat muscle and joint pain and taken internally to promote abortions.
Germany’s Commission E has approved rosemary leaf for treatment of dyspepsia (non-specific digestive distress) and rosemary oil (used externally) for joint pain and poor circulation. However, there is no meaningful scientific evidence that rosemary is effective for any of these uses. Only double-blind, placebo-controlled studies can prove that a treatment really works, and no studies of this type have found rosemary effective. (For information on why such studies are essential, see Why Does This Database Rely on Double-blind Studies?)
Rosemary essential oil, like many essential oils, has antimicrobial properties when it comes in direct contact with bacteria and other microorganisms.1-5 Note, however, that is does not mean that rosemary oil is an antibiotic. Antibiotics are substances that can be taken internally to kill microorganisms throughout the body. Rosemary oil, rather, has shown potential antiseptic properties.
Rosmarinic acid from rosemary has shown potential anti-inflammatory and anti-allergic actions, but most published studies (including double-blind trials) have used a different plant source of the substance (the herb Perilla frutescens).17-22
One controlled study failed to find rosemary cream protective against skin irritation caused by sodium lauryl-sulfate (a common ingredient of cosmetic products).23
Rosemary essential oil has been used in aromatherapy (treating conditions through scent). One controlled study evaluated rosemary aromatherapy for enhancing memory, but found results that were mixed at best.24 Another study failed to find that rosemary aromatherapy reduced tension during an anxiety-provoking task; in fact, it appeared that use of rosemary actually increased anxiety.25
A typical dosage of rosemary leaf is 4-6 grams daily. Rosemary essential oil should not be used internally.
Although rosemary’s use as a food spice suggests a relatively low level of toxicity, rosemary has not undergone comprehensive safety testing. Rosemary essential oil can be toxic if taken even in fairly low doses, and the maximum safe dose is not known.
Based on its traditional use for abortion, as well as preliminary evidence showing embryotoxic effects,26 rosemary should not be used by pregnant women or women who wish to become pregnant.
Other weak evidence hints that rosemary may enhance the liver’s rate of deactivating estrogen in the body.28 This suggests that rosemary might present risks for females, as well as anyone who uses medications containing estrogen.
1. Santoyo S, Cavero S, Jaime L, et al. Chemical composition and antimicrobial activity of Rosmarinus officinalis L. essential oil obtained via supercritical fluid extraction. J Food Prot. 2005;68:790-795.
2. Oluwatuyi M, Kaatz GW, Gibbons S, et al. Antibacterial and resistance modifying activity of Rosmarinusofficinalis. Phytochemistry. 2004;65:3249-3254.
3. Lai PK, Roy J. Antimicrobial and chemopreventive properties of herbs and spices. Curr Med Chem. 2004;11:1451-1460.
4. Mangena T, Muyima NY. Comparative evaluation of the antimicrobial activities of essential oils of Artemisia afra, Pteronia incana and Rosmarinus officinalis on selected bacteria and yeast strains. Lett Appl Microbiol. 1999;28:291-296.
5. Larrondo JV, Agut M, Calvo-Torras MA. Antimicrobial activity of essences from labiates. Microbios. 1995;82:171-172.
6. Hosseinzadeh H, Nourbakhsh M. Effect of Rosmarinus officinalis L. aerial parts extract on morphine withdrawal syndrome in mice. Phytother Res. 2003;17:938-941.
7. Yamamoto J, Yamada K, Naemura A, et al. Testing various herbs for antithrombotic effect. Nutrition. 2005;21:580-587.
8. Zhu BT, Loder DP, Cai MX, et al. Dietary administration of an extract from rosemary leaves enhances the liver microsomal metabolism of endogenous estrogens and decreases their uterotropic action in CD-1 mice. Carcinogenesis. 1998;19:1821-1827.
9. Singletary KW, Nelshoppen JM. Inhibition of 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumorigenesis and of in vivo formation of mammary DMBA-DNA adducts by rosemary extract. Cancer Lett. 1991;60:169-175.
10. Slamenova D, Kuboskova K, Horvathova E, et al. Rosemary-stimulated reduction of DNA strand breaks and FPG-sensitive sites in mammalian cells treated with H2O2 or visible light-excited Methylene Blue. Cancer Lett. 2002;177:145-153.
11. Offord EA, Mace K, Ruffieux C, et al. Rosemary components inhibit benzo[a]pyrene-induced genotoxicity in human bronchial cells. Carcinogenesis. 1995;16:2057-2062.
12. Haloui M, Louedec L, Michel JB, et al. Experimental diuretic effects of Rosmarinus officinalis and Centauriumerythraea. J Ethnopharmacol. 2000;71:465-472.
13. Fahim FA, Esmat AY, Fadel HM, et al. Allied studies on the effect of Rosmarinus officinalis L. on experimental hepatotoxicity and mutagenesis. Int J Food Sci Nutr. 1999;50:413-427.
14. Hoefler C, Fleurentin J, Mortier F, et al. Comparative choleretic and hepatoprotective properties of young sprouts and total plant extracts of Rosmarinus officinalis in rats. J Ethnopharmacol. 1987;19:133-143.
15. Vitaglione P, Morisco F, Caporaso N, et al. Dietary antioxidant compounds and liver health. Crit Rev Food Sci Nutr. 2005;44:575-586.
16. Dias PC, Foglio MA, Possenti A, et al. Antiulcerogenic activity of crude hydroalcoholic extract of Rosmarinusofficinalis L. J Ethnopharmacol. 2000;69:57-62.
17. Osakabe N, Takano H, Sanbongi C, et al. Anti-inflammatory and anti-allergic effect of rosmarinic acid (RA); inhibition of seasonal allergic rhinoconjunctivitis (SAR) and its mechanism. Biofactors. 2005;21:127-131.
18. Takano H, Osakabe N, Sanbongi C, et al. Extract of Perilla frutescens enriched for rosmarinic acid, a polyphenolic phytochemical, inhibits seasonal allergic rhinoconjunctivitis in humans. Exp Biol Med (Maywood). 2004;229:247-254.
19. Makino T, Furuta Y, Wakushima H, et al. Anti-allergic effect of Perilla frutescens and its active constituents. Phytother Res. 2003;17:240-243.
20. Makino T, Furuta A, Fujii H, et al. Effect of oral treatment of Perilla frutescens and its constituents on type-I allergy in mice. Biol Pharm Bull. 2001;24:1206-1209.
21. Youn J, Lee KH, Won J, et al. Beneficial effects of rosmarinic acid on suppression of collagen induced arthritis. J Rheumatol. 2003;30:1203-1207.
22. Osakabe N, Yasuda A, Natsume M, et al. Rosmarinic acid inhibits epidermal inflammatory responses: anticarcinogenic effect of Perilla frutescens extract in the murine two-stage skin model. Carcinogenesis. 2004;25:549-557.
23. Fuchs SM, Schliemann-Willers S, Fischer TW, et al. Protective effects of different marigold ( Calendula officinalis L.) and rosemary cream preparations against sodium-lauryl-sulfate-induced irritant contact dermatitis. Skin Pharmacol Physiol. 2005;18:195-200.
24. Moss M, Cook J, Wesnes K, et al. Aromas of rosemary and lavender essential oils differentially affect cognition and mood in healthy adults. Int J Neurosci. 2003;113:15-38.
25. Burnett KM, Solterbeck LA, Strapp CM, et al. Scent and mood state following an anxiety-provoking task. Psychol Rep. 2004;95:707-722.
26. Lemonica IP, Damasceno DC, di-Stasi LC. Study of the embryotoxic effects of an extract of rosemary ( Rosmarinus officinalis L.). Braz J Med Biol Res. 1996;29:223-227.
27. Pyevich D, Bogenschutz MP. Herbal diuretics and lithium toxicity. Am J Psychiatry. 2001;158:1329.
28. Zhu BT, Loder DP, Cai MX, et al. Dietary administration of an extract from rosemary leaves enhances the liver microsomal metabolism of endogenous estrogens and decreases their uterotropic action in CD-1 mice. Carcinogenesis. 1998;19:1821-1827.
29. al-Hader AA, Hasan ZA, Aqel MB. Hyperglycemic and insulin release inhibitory effects of Rosmarinusofficinalis. J Ethnopharmacol. 1994;43:217-221.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015