Borage

Other Name(s):

Bee Plant, Beebread, Borage Flower, Borage Leaf, Borage Oil, Borage Seed Oil, Borago, Borago officinalis, Borraja, Bourrache, Bourrache Commune, Burage, Burrage, Common Borage, Common Bugloss, Cool Tankard, Feuille de Bourrache, Fleur de Bourrache, Huile de Bourrache, Huile de Graines de Bourrache, Langue de Bœuf, Ox's Tongue, Pain-des-Abeilles, Talewort, Starflower, Starflower Oil.

Overview

Borage is a plant. Its flowers and leaves, as well as the oil from its seeds are used as medicine.

Borage seed oil is used for skin disorders including eczema, seborrheic dermatitis, and neurodermatitis. It is also used for rheumatoid arthritis (RA), stress, premenstrual syndrome (PMS), diabetes, attention deficit-hyperactivity disorder (ADHD), acute respiratory distress syndrome (ARDS), alcoholism, pain and swelling (inflammation), and for preventing heart disease and stroke.

Borage flower and leaves are used for fever, cough, and depression.

Borage is also used for a hormone problem called adrenal insufficiency, for "blood purification," to increase urine flow, to prevent inflammation of the lungs, as a sedative, and to promote sweating. Borage is also used to increase breast milk production and to treat bronchitis and colds.

Borage is applied to the skin for infantile seborrheic dermatitis and is also used in a dressing to soften the skin.

In foods, borage is eaten in salads and soups.

In manufacturing, borage is used in skin care products.

How does work?

Borage seed oil contains a fatty acid called gamma-linolenic acid (GLA). GLA seems to have anti-inflammatory effects. Borage flower might have an antioxidant effect.

QUESTION

The term arthritis refers to stiffness in the joints. See Answer

Uses

Possibly Effective for...

  • Improving the function of the lungs in critically ill patients. There is some evidence that borage seed oil, when taken by mouth in combination with eicosapentaenoic acid (EPA), might reduce the number of days spent in the intensive care unit (ICU) and the length of time a breathing machine is needed by patients with acute respiratory distress syndrome (ARDS).
  • Growth and development in premature infants. Infant formula supplemented with fatty acids from borage oil and fish oils seems to improve growth and development of the nervous system in infants born early, especially boys.
  • Rheumatoid arthritis (RA).There is some evidence that taking borage seed oil in combination with conventional painkilling or anti-inflammatory medications might help decrease symptoms of RA after six weeks of treatment. The improvement appears to last for up to 24 weeks. Improvement is measured as a decrease in the number and severity of tender and swollen joints.

Possibly Ineffective for...

  • Itchy, red skin (eczema). Taking borage seed oil by mouth does not seem to improve eczema in adults or children.

Insufficient Evidence to Rate Effectiveness for...

  • Asthma. Early research suggests that taking borage oil daily for 12 months does not improve asthma symptoms.
  • A dental condition called periodontitis. Early research suggests that taking borage oil daily for 12 weeks improves gum inflammation but does not reduce plaque in people with periodontitis.
  • Skin conditions in infants. There is some evidence that topical application of borage seed oil might be helpful for infantile seborrheic dermatitis. It seems to heal the condition within 1 to 3 weeks.
  • Premenstrual syndrome (PMS).
  • Diabetes.
  • Attention deficit-hyperactivity disorder (ADHD).
  • Alcoholism.
  • Heart disease.
  • Stroke.
  • Fever.
  • Cough.
  • Depression.
  • Dry skin.
  • Arthritis.
  • Pain relief.
  • Inflamed veins (phlebitis).
  • Menopausal disorders.
  • Fluid retention.
  • Other conditions.
More evidence is needed to rate the effectiveness of borage for these uses.

Side Effects

Borage seed oil is POSSIBLY SAFE when taken by mouth or applied to the skin appropriately.

Borage seed oil is LIKELY UNSAFE when products containing a dangerous chemicals called pyrrolizidine alkaloids (PAs) are taken by mouth. Borage plant parts including the leaf, flower, and seed can contain PAs. PAs can damage the liver or cause cancer, especially when used in high doses or for a long time. Only use products that are certified and labeled PA-free.

Precautions

Children: Borage see oil is POSSIBLY SAFE when taken by mouth appropriately. Borage seed oil is LIKELY UNSAFE when products containing PA are taken by mouth.

Pregnancy and breast-feeding: Borage seed oil is LIKELY UNSAFE during pregnancy and while breast-feeding. It is important to avoid borage products that might contain pyrrolizidine alkaloids (PAs). PAs are a risk to the mother because they can cause serious liver disease and might cause cancer. PAs are also a risk to the infant because they might cause birth defects and they can pass into breast milk. Researchers are not sure if borage products that are certified PA-free are safe during pregnancy and breast-feeding. It is best to stay safe and avoid using borage.

Bleeding disorders: There is some concern that borage seed oil might prolong bleeding time and increase the risk of bruising and bleeding. If you have a bleeding disorder, use borage with caution.

Liver disease: Borage products containing hepatotoxic pyrrolizidine alkaloids (PA) might make liver disease worse.

Surgery: Borage might increase the risk of bleeding during and after surgery. Stop taking borage at least 2 weeks before a scheduled surgery.

Interactions


Medications that increase the breakdown of other medications by the liver (Cytochrome P450 3A4 (CYP3A4) inducers)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Borage is broken down by the liver. Some chemicals that form when the liver breaks down borage seed oil can be harmful. Medications that cause the liver to break down borage seed oil might enhance the toxic effects of chemicals contained in borage seed oil.

Some of these medicines include carbamazepine (Tegretol), phenobarbital, phenytoin (Dilantin), rifampin, rifabutin (Mycobutin), and others.


Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Borage seed oil might slow blood clotting in some people. Borage seed oil contains GLA (gamma linolenic acid). GLA is the part of borage seed oil that might slow blood clotting. Taking borage seed oil along with medications that also slow clotting might increase the chances of bruising and bleeding.

Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.


Medications used during surgery (Anesthesia)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Borage seed oil might interact with medications used during surgery. Be sure to tell your doctor what natural products you are taking before having surgery. To be on the safe side, you should stop taking borage seed oil at least two weeks before surgery.


NSAIDs (Nonsteroidal anti-inflammatory drugs)Interaction Rating: Minor Be cautious with this combination.Talk with your health provider.

NSAIDs are anti-inflammatory medications used to decrease pain and swelling. Borage seed oil is also used as an anti-inflammatory medication. Sometimes NSAIDs and borage seed oil are used together for rheumatoid arthritis. However, borage seed oil seems to work in a different way than NSAIDs. Some scientists think that taking NSAIDs along with borage seed oil might decrease the effectiveness of borage seed oil. But it is too soon to know if this is true.

Some NSAIDs include ibuprofen (Advil, Motrin, Nuprin, others), indomethacin (Indocin), naproxen (Aleve, Anaprox, Naprelan, Naprosyn), piroxicam (Feldene), aspirin, and others.

Dosing

The following doses have been studied in scientific research:

javascript:txtEnCSafetyConcernssize(); BY MOUTH:

  • For rheumatoid arthritis (RA): 1.1 or 1.4 grams of borage seed oil daily for up to 24 weeks.

SLIDESHOW

What Is Rheumatoid Arthritis (RA)? Symptoms, Treatment, Diagnosis See Slideshow

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

References

Bahmer, F. A. and Schafer, J. [Treatment of atopic dermatitis with borage seed oil (Glandol)--a time series analytic study]. Kinderarztl.Prax. 1992;60(7):199-202. View abstract.

Bard, J. M., Luc, G., Jude, B., Bordet, J. C., Lacroix, B., Bonte, J. P., Parra, H. J., and Duriez, P. A therapeutic dosage (3 g/day) of borage oil supplementation has no effect on platelet aggregation in healthy volunteers. Fundam.Clin.Pharmacol. 1997;11(2):143-144. View abstract.

Barre, D. E. and Holub, B. J. The effect of borage oil consumption on the composition of individual phospholipids in human platelets. Lipids 1992;27(5):315-320. View abstract.

Borrek, S., Hildebrandt, A., and Forster, J. [Gamma-linolenic-acid-rich borage seed oil capsules in children with atopic dermatitis. A placebo-controlled double-blind study]. Klin.Padiatr. 1997;209(3):100-104. View abstract.

Brustbauer, R. and Wenisch, C. [Bradycardiac atrial fibrillation after consuming herbal tea]. Dtsch.Med Wochenschr. 7-25-1997;122(30):930-932. View abstract.

Cardano, S., Beldi, F., Bignoli, C., Monteverde, A., and Uglietti, E. [A dangerous "risotto"]. Recenti Prog Med 2002;93(4):245-246. View abstract.

Chilton, Lopez, Surette, M. E., Swan, D. D., Fonteh, A. N., Johnson, M. M., and Chilton, F. H. Metabolism of gammalinolenic acid in human neutrophils. J Immunol 4-15-1996;156(8):2941-2947. View abstract.

Christophe, A., Robberecht, E., Franckx, H., De Baets, F., and van de, Pas M. Effect of administration of gamma-linolenic acid on the fatty acid composition of serum phospholipids and cholesteryl esters in patients with cystic fibrosis. Ann.Nutr Metab 1994;38(1):40-47. View abstract.

Chrubasik, S. and Pollak, S. [Pain management with herbal antirheumatic drugs]. Wien.Med Wochenschr. 2002;152(7-8):198-203. View abstract.

Demmelmair, H., Feldl, F., Horvath, I., Niederland, T., Ruszinko, V., Raederstorff, D., De Min, C., Muggli, R., and Koletzko, B. Influence of formulas with borage oil or borage oil plus fish oil on the arachidonic acid status in premature infants. Lipids 2001;36(6):555-566. View abstract.

Dooper, M. M., van Riel, B., Graus, Y. M., and M'Rabet, L. Dihomo-gamma-linolenic acid inhibits tumour necrosis factor-alpha production by human leucocytes independently of cyclooxygenase activity. Immunology 2003;110(3):348-357. View abstract.

Fokkema, M. R., Brouwer, D. A., Hasperhoven, M. B., Martini, I. A., and Muskiet, F. A. Short-term supplementation of low-dose gamma-linolenic acid (GLA), alpha-linolenic acid (ALA), or GLA plus ALA does not augment LCP omega 3 status of Dutch vegans to an appreciable extent. Prostaglandins Leukot.Essent.Fatty Acids 2000;63(5):287-292. View abstract.

Harbige, L. S. and Fisher, B. A. Dietary fatty acid modulation of mucosally-induced tolerogenic immune responses. Proc Nutr Soc 2001;60(4):449-456. View abstract.

Kapoor, R. and Klimaszewski, A. Efficacy of borage oil in patients with atopic eczema. Br J Dermatol 2000;143(1):200-201. View abstract.

Karia, C., Harwood, J. L., Morris, A. P., and Heard, C. M. Simultaneous permeation of tamoxifen and gamma linolenic acid across excised human skin. Further evidence of the permeation of solvated complexes. Int J Pharm 3-1-2004;271(1-2):305-309. View abstract.

Loden, M. and Andersson, A. C. Effect of topically applied lipids on surfactant-irritated skin. Br J Dermatol 1996;134(2):215-220. View abstract.

Miles, E. A., Banerjee, T., and Calder, P. C. The influence of different combinations of gamma-linolenic, stearidonic and eicosapentaenoic acids on the fatty acid composition of blood lipids and mononuclear cells in human volunteers. Prostaglandins Leukot.Essent.Fatty Acids 2004;70(6):529-538. View abstract.

Mills, D. E., Mah, M., Ward, R. P., Morris, B. L., and Floras, J. S. Alteration of baroreflex control of forearm vascular resistance by dietary fatty acids. Am J Physiol 1990;259(6 Pt 2):R1164-R1171. View abstract.

Mills, D. E., Prkachin, K. M., Harvey, K. A., and Ward, R. P. Dietary fatty acid supplementation alters stress reactivity and performance in man. J Hum.Hypertens. 1989;3(2):111-116. View abstract.

O'Mahony, R., Al Khtheeri, H., Weerasekera, D., Fernando, N., Vaira, D., Holton, J., and Basset, C. Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori. World J Gastroenterol. 12-21-2005;11(47):7499-7507. View abstract.

Palombo, J. D., DeMichele, S. J., Boyce, P. J., Lydon, E. E., Liu, J. W., Huang, Y. S., Forse, R. A., Mizgerd, J. P., and Bistrian, B. R. Effect of short-term enteral feeding with eicosapentaenoic and gamma-linolenic acids on alveolar macrophage eicosanoid synthesis and bactericidal function in rats. Crit Care Med 1999;27(9):1908-1915. View abstract.

Pittler, M. H., Verster, J. C., and Ernst, E. Interventions for preventing or treating alcohol hangover: systematic review of randomised controlled trials. BMJ 12-24-2005;331(7531):1515-1518. View abstract.

Rosenstein, E. D., Kushner, L. J., Kramer, N., and Kazandjian, G. Pilot study of dietary fatty acid supplementation in the treatment of adult periodontitis. Prostaglandins Leukot.Essent.Fatty Acids 2003;68(3):213-218. View abstract.

Rossetti, R. G., Seiler, C. M., DeLuca, P., Laposata, M., and Zurier, R. B. Oral administration of unsaturated fatty acids: effects on human peripheral blood T lymphocyte proliferation. J Leukoc.Biol 1997;62(4):438-443. View abstract.

Sayanova, O., Shewry, P. R., and Napier, J. A. Histidine-41 of the cytochrome b5 domain of the borage delta6 fatty acid desaturase is essential for enzyme activity. Plant Physiol 1999;121(2):641-646. View abstract.

Tollesson, A. and Frithz, A. Transepidermal water loss and water content in the stratum corneum in infantile seborrhoeic dermatitis. Acta Derm.Venereol 1993;73(1):18-20. View abstract.

Tsui, B., Dennehy, C. E., and Tsourounis, C. A survey of dietary supplement use during pregnancy at an academic medical center. Am J Obstet Gynecol. 2001;185(2):433-437. View abstract.

van Gool, C. J., Thijs, C., Henquet, C. J., van Houwelingen, A. C., Dagnelie, P. C., Schrander, J., Menheere, P. P., and van den brandt, P. A. Gamma-linolenic acid supplementation for prophylaxis of atopic dermatitis--a randomized controlled trial in infants at high familial risk. Am J Clin Nutr 2003;77(4):943-951. View abstract.

Westman, E. C., Yancy, W. S., Jr., Olsen, M. K., Dudley, T., and Guyton, J. R. Effect of a low-carbohydrate, ketogenic diet program compared to a low-fat diet on fasting lipoprotein subclasses. Int J Cardiol. 6-16-2006;110(2):212-216. View abstract.

Wold, R. S., Lopez, S. T., Yau, C. L., Butler, L. M., Pareo-Tubbeh, S. L., Waters, D. L., Garry, P. J., and Baumgartner, R. N. Increasing trends in elderly persons' use of nonvitamin, nonmineral dietary supplements and concurrent use of medications. J Am Diet.Assoc 2005;105(1):54-63. View abstract.

Ziboh, V. A. and Fletcher, M. P. Dose-response effects of dietary gamma-linolenic acid-enriched oils on human polymorphonuclear-neutrophil biosynthesis of leukotriene B4. Am J Clin Nutr 1992;55(1):39-45. View abstract.

Ziboh, V. A., Naguwa, S., Vang, K., Wineinger, J., Morrissey, B. M., Watnik, M., and Gershwin, M. E. Suppression of leukotriene B4 generation by ex-vivo neutrophils isolated from asthma patients on dietary supplementation with gammalinolenic acid-containing borage oil: possible implication in asthma. Clin.Dev.Immunol. 2004;11(1):13-21. View abstract.

Bandoniene D, Murkovic M. The detection of radical scavenging compounds in crude extract of borage (Borago officinalis L.) by using an on-line HPLC-DPPH method. J Biochem Biophys Methods 2002;53:45-9. View abstract.

Barre DE. Potential of evening primrose, borage, black currant, and fungal oils in human health. Ann Nutr Metab 2001;45:47-57. View abstract.

Belch J, Hill A. Evening primrose oil and borage oil in rheumatologic conditions. Am J Clin Nutr 2000;71:352S-6S. View abstract.

Chojkier M. Hepatic sinusoidal-obstruction syndrome: toxicity of pyrrolizidine alkaloids. J Hepatol 2003;39:437-46. View abstract.

DeLuca P, Rothman D, Zurier RB. Marine and botanical lipids as immunomodulatory and therapeutic agents in the treatment of rheumatoid arthritis. Rheum Dis Clin North Am 1995;21:759-77. View abstract.

Dodson CD, Stermitz FR. Pyrrolizidine alkaloids from borage (Borago officinalis) seeds and flowers. J Nat Prod 1986;49:727-8.

Dr. Duke's Phytochemical and Ethnobotanical Databases. Available at: http://www.ars-grin.gov/duke/.

Engler MM, Engler MB, Erickson SK, Paul SM. Dietary gamma-linolenic acid lowers blood pressure and alters aortic reactivity and cholesterol metabolism in hypertension. J Hypertens 1992;10:1197-204. View abstract.

Fan YY, Chapkin RS. Importance of dietary gamma-linolenic acid in human health and nutrition. J Nutr 1998;128:1411-4. View abstract.

Fan YY, Chapkin RS. Importance of dietary gamma-linolenic acid in human health and nutrition. J Nutr 1998;128:1411-4. View abstract.

Fewtrell MS, Abbott RA, Kennedy K, et al. Randomized, double-blind trial of long-chain polyunsaturated fatty acid supplementation with fish oil and borage oil in preterm infants. J Pediatr 2004;144:471-9. View abstract.

Fisher BAC, Harbige LS. Effect of omega-6 lipid-rich borage oil feeding on immune function in healthy volunteers (abstract). Biochem Soc Trans 1997;25:343S. View abstract.

Food and Drug Administration. FDA Advises Dietary Supplement Manufacturers to Remove Comfrey Products From the Market. July 6, 2001. Available at: http://www.cfsan.fda.gov/~dms/dspltr06.html.

Furse RK, Rossetti RG, Seiler CM, Zurier RB. Oral administration of gammalinolenic acid, an unsaturated fatty acid with anti-inflammatory properties, modulates interleukin-1beta production by human monocytes. J Clin Immunol 2002;22:83-91. View abstract.

Gadek JE, DeMichele SJ, Karlstad MD, et al. Effect of enteral feeding with eicosapentaenoic acid, gamma-linolenic acid, and antioxidants in patients with acute respiratory distress syndrome. Enteral Nutrition in ARDS Study Group. Crit Care Med 1999;27:1409-20. View abstract.

Guivernau M, Meza N, Barja P, Roman O. Clinical and experimental study on the long-term effect of dietary gamma-linolenic acid on plasma lipids, platelet aggregation, thromboxane formation, and prostacyclin production. Prostaglandins Leukot Essent Fatty Acids 1994;51:311-6. View abstract.

Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm 2000;57:1221-7. View abstract.

Henz BM, Jablonska S, van de Kerkhof PC, et al. Double-blind, multicentre analysis of the efficacy of borage oil in patients with atopic eczema. Br J Dermatol 1999;140:685-8. View abstract.

Henz BM. Efficacy of borage oil in patients with atopic eczema - reply from author. Br J Dermatol 2000;143:201. View abstract.

Kalantar-Zadeh, K., Braglia, A., Chow, J., Kwon, O., Kuwae, N., Colman, S., Cockram, D. B., and Kopple, J. D. An anti-inflammatory and antioxidant nutritional supplement for hypoalbuminemic hemodialysis patients: a pilot/feasibility study. J Ren Nutr 2005;15(3):318-331. View abstract.

Kast RE. Boarge oil reduction of rheumatoid arthritis activity may be mediated by increased cAMP that suppresses tumor necrosis factor-alpha. Int Immunopharmacol 2001;1:2197-9. View abstract.

Larson KM, Roby MR, Stermitz FR. Unsaturated pyrrolizidines from borage (Borago officinalis), a common garden herb. J Nat Prod 1984;47:747-8.

Leventhal LJ, Boyce EG, Zurier RB. Treatment of rheumatoid arthritis with gammalinolenic acid. Ann Intern Med 1993;119:867-73. View abstract.

Menendez JA, Colomer R, Lupu R. Omega-6 polyunsaturated fatty acid gamma-linolenic acid (18:3n-6) is a selective estrogen-response modulator in human breast cancer cells: gamma-Linolenic acid antagonizes estrogen receptor-dependent transcriptional activity, transcriptionally represses estrogen receptor expression and synergistically enhances tamoxifen and ICI 182,780 (Faslodex) efficacy in human breast cancer cells. Int J Cancer 2004;10;109:949-54. View abstract.

Menendez JA, del Mar Barbacid M, Montero S, et al. Effects of gamma-linolenic acid and oleic acid on paclitaxel cytotoxicity in human breast cancer cells. Eur J Cancer 2001;37:402-13. View abstract.

Miller LG. Herbal Medicinals: Selected clinical considerations focusing on known or potential drug-herb interactions. Arch Intern Med 1998;158:2200-11. View abstract.

Morse PF, Horrobin DF, Manku MS, et al. Meta-analysis of placebo-controlled studies of the efficacy of Epogam in the treatment of atopic eczema. Relationship between plasma essential fatty acid changes and clinical response. Br J Dermatol 1989;121:75-90. View abstract.

Pullman-Mooar S, Laposata M, Lem D. Alteration of the cellular fatty acid profile and the production of eicosanoids in human monocytes by gamma-linolenic acid. Arthritis Rheum 1990;33:1526-33. View abstract.

Roeder E. Medicinal plants in Europe containing pyrrolizidine alkaloids. Pharmazie 1995;50:83-98.

Rose DP, Connolly JM, Liu XH. Effects of linoleic acid and gamma-linolenic acid on the growth and metastasis of a human breast cancer cell line in nude mice and on its growth and invasive capacity in vitro. Nutr Cancer 1995;24:33-45. . View abstract.

Rothman D, DeLuca P, Zurier RB. Botanical lipids: effects on inflammation, immune responses, and rheumatoid arthritis. Semin Arthritis Rheum 1995;25:87-96. View abstract.

Shaw D, Leon C, Kolev S, Murray V. Traditional remedies and food supplements: a 5-year toxicological study (1991-1995). Drug Saf 1997;17:342-56. View abstract.

Stedman C. Herbal hepatotoxicity. Semin Liver Dis 2002;22:195-206. View abstract.

Takwale A, Tan E, Agarwal S, et al. Efficacy and tolerability of borage oil in adults and children with atopic eczema: randomised, double blind, placebo controlled, parallel group trial. BMJ 2003;327:1385. View abstract.

Thijs C, van Houwelingen A, Poorterman I, et al. Essential fatty acids in breast milk of atopic mothers: comparison with non-atopic mothers, and effect of borage oil supplementation. Eur J Clin Nutr 2000;54:234-8. View abstract.

Tollesson A, Frithz A, Stenlund K. Malassezia furfur in infantile seborrheic dermatitis. Pediatr Dermatol 1997;14:423-5. View abstract.

Tollesson A, Frithz A. Borage oil, an effective new treatment for infantile seborrhoeic dermatitis. Br J Dermatol 1993;129:95. View abstract.

van Gool CJ, Zeegers MP, Thijs C. Oral essential fatty acid supplementation in atopic dermatitis-a meta-analysis of placebo-controlled trials. Br J Dermatol 2004;150:728-40. View abstract.

Wang YP, Yan J, Fu PP, Chou MW. Human liver microsomal reduction of pyrrolizidine alkaloid N-oxides to form the corresponding carcinogenic parent alkaloid. Toxicol Lett 2005;155:411-20. View abstract.

WHO working group. Pyrrolizidine alkaloids. Environmental Health Criteria, 80. WHO: Geneva, 1988.

Wretensjo I. Characterisation of borage oil by GC-MS. Licentiate Thesis, Stockholm University, 2004. Available at: http://www.anchem.su.se/downloads/diss_pdf/i_wretensjo_lic2004.pdf.