Practical ecological knowledge for the temperate reader.

Borago officinalis - Common Borage

Family: Boraginaceae (Borage family) [E-flora]

Other names: Starflower [HMI Stockey]

"Borago officinalis is a ANNUAL growing to 0.6 m (2ft) by 0.3 m (1ft in) at a medium rate.
It is hardy to zone (UK) 7 and is not frost tender. It is in flower from Jun to October, and the seeds ripen from Jul to October. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Bees.It is noted for attracting wildlife.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: acid, neutral and basic (alkaline) soils and can grow in very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil and can tolerate drought." [PFAF]

"General Annual herb from a taproot, stiff-hairy or bristly, with cucumber-scented juice; stems ascending to erect, usually branching above, 20-70 cm tall." [IFBC-E-flora]

"Habitat / Range Dry to moist waste places in the steppe and lower montane zones; rare in S BC; introduced from Europe." [IFBC-E-flora]

Status: Exotic [E-flora]


"Long-term use is not recommended (AHP). Not approved (KOM). “Hazards and/or side effects not known for proper therapeutic dosages” (PH2). Commission E reports borage contains hepatotoxic and carcinogenic pyrrolizidine alkaloids (AEH). “Effective July 1996, the AHP Board of Trustees recommends that all products with botanical ingredient(s) which contain toxic pyrrolizidine alkaloids, including Borago officinalis, display the following cautionary statement on the label: For external use only. Do not apply to broken or abraded skin. Do not use when nursing.” (AHP). Pyrrolizidine alkaloids (PAs) have genotoxic, carcinogenic, and hepatotoxic activity (CAN). Because of the PAs, its use in pregnancy and lactation is to be avoided. Animal studies document placental transfer and secretion into breast milk of unsaturated PAs (CAN). Swiss researchers report at least seven PAs from the herb, at levels above those permitted in Germany (>1 ppm). Seeds reportedly contain even higher quantities of alkaloids (De Smet et al., 1993). Tannins have astringent activities (PHR). Mucilage acts as a sequestering agent (PHR). The GLA in the seed oil may have been positive effects if divorced from the potential of PA toxicity." [HMH Duke]

"Evening primrose oil is recommended to be used with caution in epileptic patients, especially in those with schizophrenia and/or those taking phenothiazines (see Evening Primrose); on the basis that borage oil, like evening primrose oil, also contains high concentrations of gamolenic acid, borage oil should also be used with caution in these patient groups. In view of the known toxic pyrrolizidine alkaloid constituents, excessive or prolonged ingestion of borage should be avoided. In particular, infusions (e.g. herbal teas) containing borage should be avoided." [HerbalMed3]

Borage Oil: "No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages." [PDR]

Borage Leaf: "Even though the hepatotoxic and hepatocarcinogenic pyrrolizidine alkaloid content is small, the drug should not be administered. External use may present less of a potential for problems." [PDR]

"Drug interactions None documented. However, the potential for preparations of borage to interact with other medicines administered concurrently, particularly those with similar or opposing effects, should be considered." [HerbalMed3] "Evening primrose oil contains linoleic acid and gamolenic acid, which are the main active constituents implicated in its interactions. Starflower oil also contains these constituents, and is therefore expected to interact in the same way." [HMI Stockey]

"Pregnancy and lactation In view of the documented pyrrolizidine constituents and lack of toxicity data, borage should not be used during pregnancy or lactation." [HerbalMed3]

Pyrrolizidine alkaloids

"The plant, but not the oil obtained from the seeds, contains small amounts of pyrrolizidine alkaloids that can cause liver damage and liver cancer[238]. These alkaloids are present in too small a quantity to be harmful unless you make borage a major part of your diet, though people with liver problems would be wise to avoid using the leaves or flowers of this plant[K]." [PFAF]

"Starflower leaves contain potentially hepatotoxic pyrrolizidine alkaloids including lycopsamine, intermedine and their derivatives." [HMI Stockey]

Edible Uses

Other Uses

Medicinal Uses

"Borage is a fairly common domestic herbal remedy that has been used since ancient times[244]. It has a particularly good reputation for its beneficial affect on the mind, being used to dispel melancholy and induce euphoria[244]. It is a soothing saline, diuretic herb that soothes damaged or irritated tissues[238]" [PFAF] "Borage is stated to possess diaphoretic, expectorant, tonic, antiinflammatory and galactogogue properties.(3) Traditionally, borage has been used to treat many ailments including fevers, coughs and depression.(3,G42, G64) Borage is also reputed to act as a restorative agent on the adrenal cortex.(3) Borage oil (starflower oil) is used as an alternative source to evening primrose oil for gamolenic acid." [HerbalMed3] "The medicinal parts are the dried Borage flowers and the dried or fresh foliage, stems and leaves." [PDR]

"In a study of 80 patients treated with 500 mg borage oil daily for 24 weeks, there were no definite herb - related adverse effects. One patient was withdrawn from the study for headache, diarrhea, and vomiting, but these effects could not be causally linked to borage oil." [MTNS]
"There are few data including case reports on the toxicity of borage or borage oil." [MTNS]
"A case report associated the development of atrial fibrillation, bradycardia, and gastrointestinal distress in a 72 - year - old woman, who drank tea from leaves that she thought were borage. 1 Subsequent laboratory analysis indicated that she confused borage leaves for foxglove, and thus she probably had digitoxin poisoning." [MTNS]

  • ACETIC-ACID Plant: DUKE1992A
  • ALKALOIDS Plant 2 - 98 ppm DUKE1992A
  • ALLANTOIN Sprout Seedling: DUKE1992A
  • ARABINOSE Plant: DUKE1992A
  • ASCORBIC-ACID Leaf 30 - 5,005 ppm DUKE1992A
  • BETA-CAROTENE Leaf 25 - 360 ppm DUKE1992A
  • CALCIUM Leaf 930 - 5,005 ppm DUKE1992A
  • CARBOHYDRATES Leaf 30,600 - 437,580 ppm DUKE1992A
  • CHOLINE Leaf: DUKE1992A
  • COBALT Plant: DUKE1992A
  • DHURRIN Plant: DUKE1992A
  • FAT Leaf 7,000 - 100,000 ppm DUKE1992A Seed 383,000 ppm; DUKE1992A
  • FIBER Leaf 9,200 - 131,560 ppm DUKE1992A
  • GALACTOSE Plant: DUKE1992A
  • GLUCOSE Plant: DUKE1992A
  • IRON Leaf 33 - 472 ppm DUKE1992A
  • LACTIC-ACID Plant: DUKE1992A
  • MAGNESIUM Leaf 520 - 7,436 ppm DUKE1992A
  • MALIC-ACID Plant: DUKE1992A
  • MUCILAGE Plant 300,000 ppm; DUKE1992A
  • NIACIN Leaf 9 - 129 ppm DUKE1992A
  • PHOSPHORUS Leaf 530 - 7,579 ppm DUKE1992A
  • POTASSIUM Leaf 4,700 - 67,210 ppm DUKE1992A
  • PROTEIN Leaf 18,000 - 257,400 ppm DUKE1992A Seed 209,000 ppm; DUKE1992A
  • PYRROLIZIDINES Plant 2 - 10 ppm DUKE1992A
  • RESIN Plant: DUKE1992A
  • RIBOFLAVIN Leaf 1 - 21 ppm DUKE1992A
  • ROSMARINIC-ACID Plant 500 - 7,000 ppm DUKE1992A
  • SILICIC-ACID Plant 15,000 - 22,000 ppm DUKE1992A
  • SODIUM Plant 800 - 11,440 ppm DUKE1992A
  • SUPININE Leaf: DUKE1992A
  • TANNIN Plant 30,000 ppm; DUKE1992A
  • THIAMIN Leaf 1 - 9 ppm DUKE1992A
  • WATER Herb 930,000 ppm; DUKE1992A
  • ZINC Plant: DUKE1992A

ppm = parts per million
tr = trace


"Alkaloids Pyrrolizidine-type. Lycopsamine, intermedine, acetyllycopsamine, acetylintermedine, amabiline, supinine and thesinine (unsaturated).(1,2) Concentrations reported as 0.01% and 2– 10ppm for commercial dried samples. Alkaloid concentrations reportedly the same for fresh and dried samples; fresh samples revealed alkaloids as the free base in the roots and mainly as Noxides in the leaves." [HerbalMed3]
"Mucilages 11.1%. Yielding glucose, galactose and arabinose." [HerbalMed3]
"Oil Rich in fatty acids, in particular gamolenic acid." [HerbalMed3]
"Other constituents Acids (acetic, lactic, malic, silicic), cyanogenetic compounds and tannins (up to 3%)." [HerbalMed3]

Borage Leaf
"Pyrrolizidine alkaloids: supinin, lycopsamin, 7-acetyl-lycopsamin, intermedin, 7-acetyl- intermedine, amabiline, thesinine" [PDR]
"Silicic acid (to some extent water-soluble)" [PDR]
Mucilages [PDR]
Tannins [PDR]

Borage Oil
Constituents of borage oil include acids (acetic, lactic, malic silicic), alkaloids, fatty acids ( y - linolenic acid, linoleic acid, oleic acid, saturated fatty acids), mucilages, tannins, and saponins." [MTNS] "Fatty oil: chief fatty acid is gamma-linolenic acid (17-25%), linoleic acid" [PDR]

Linoleic, linolenic, and oleic acids comprise about 75% of the total fatty acids in borage oil. 9 y - Linolenic acid is an essential ... polyunsaturated fatty acid that also occurs in evening primrose ( Oenothera biennis L.) and black currant seed ( Ribes nigrum L.). This compound is one of at least 79 triacylglycerols present in borage oil..." [MTNS]

"The oil from starflower seeds contains the essential fatty acids of the omega-6 series, linoleic acid (about 30 to 41%) and gamolenic acid (gamma-linolenic acid, about 17 to 27%). Other fatty acids include oleic acid, alpha-linolenic acid, palmitic acid and stearic acid." [HMI Stockey]

"In addition, borage oil contains small amounts ( < 10 ppm dry weight leaves) of pyrrolizidine alkaloids (e.g., amabiline, intermedine, lycopsamine, supinine), which are potentially hepatohepatotoxic. As a result of the presence of pyrrolizidine alkaloids, the German Federal Health Agency limits the consumption of unsaturated pyrrolizidine alkaloids to <1 ug daily. Borage oils products are certified as being free of unsaturated pyrrolizidine alkaloids when the unsaturated pyrrolizidine alkaloid content is < 0.5 – 1 ug/g." [MTNS]

"Activities (Borage) — Adrenocorticostimulant (f; APA; CAN); Analgesic (f; PHR; PH2); Antiinflammatory (1; APA; CAN; FAD; PH2); Antipyretic (f; CRC; EFS; FAD; WO2); Antispasmodic (f; EFS); Aperient (f; CRC); Astringent (1; APA; PHR; PH2); Carcinogenic (1; APA; CAN); Cardiotonic (f; PHR; PH2); Collyrium (f; JFM); Demulcent (1; CAN; CRC; EFS); Depurative (f; CRC; EFS; PH2); Diaphoretic (f; CAN; CRC; EFS; JFM; PHR; PH2); Diuretic (1; APA; FAD; PNC); Emollient (f; CRC; EFA; HHB; PNC); Expectorant (f; CAN); Genotoxic (1; CAN); Hepatocarcinogenic (1; APA; PHR); Hepatotoxic (1; CRC; PHR); Hypotensive (1; CAN); Lactagogue (f; APA; CAN; CRC); Laxative (f; CRC; EFS; WO2); Nervine (f; CRC; EFS; WO2); Pectoral (f; CRC); Sedative (f; PHR; PH2); Tonic (f; CAN; CRC)." [HMH Duke]

Select Indications (Borage) — Alactea (f; APA; CAN); Arthrosis (1; APA; PHR; PH2); Bronchosis (f; APA; CRC; PHR; PH2); Cancer, breast (f; CRC); Cancer, face (f; CRC); Cardiopathy (1; APA; CRC; JFM; LAF; PHR); Conjunctivosis (f; CRC; JFM); Constipation (f; CRC; EFS; WO2); Corn (f; APA; CRC; JLH); Cough (f; CAN; CRC; HHB; JFM; PH2); Cramp (f; CRC; EFS); Cut (f; CRC); Dermatosis (1; APA; PH2); Diarrhea (1; APA; CRC; JFM); Eczema (f; CRC; LAF); Edema (f; CRC; JFM); Fever (f; CAN; CRC; EFS; FAD; JFM; PHR; PH2; WO2); Inflammation (1; APA; CAN; FAD; LAF; PH2); Insomnia (f; EFS; PHR; PH2); Jaundice (f; CRC; FAD); Kidney Stone (f; APA; CRC); Menopause (1; PHR; PH2); Nephrosis (f; CRC; PHR; PH2); Nervousness (f; PHR; PH2); Neurodermatosis (f; APA; PHR; PH2); Pain (f; CRC; PHR; PH2); Phlebitis (f; PHR; PH2); PMS (1; APA; JAD; LAF; PHR); Rheumatism (1; APA; FAD; PHR; PH2); Sclerosis (f; CRC; JLH); Sore Throat (f; CRC; HHB; PHR; PH2); Swelling (f; CRC; HHB); Tumor (f; CRC); Water Retention (1; APA; FAD; PNC). [HMH Duke]

Cultivation & Propagation

"A very easily grown plant, succeeding in ordinary garden soil[1], preferring a dry soil[37] and a sunny position[138]. It grows particularly well in loose, stony soils with some chalk and sand[244]. Plants are tolerant of poor dry soils, though much bigger specimens are produced when the plants are growing in better conditions[238]. Tolerates a pH in the range 4.8 to 8.3. Borage is often grown as a culinary plant in the herb garden[1, 7]. Although an annual, it usually maintains itself by self-sowing, sometimes in quite a prolific manner, as long as the soil is disturbed by hoeing etc[14, 188]. Plants often develop mildew when growing in dry conditions or towards the end of the growing season[238]. Flowers are a deeper blue when grown in poorer soils[138]. The flowers are rich in a sweet nectar and are very attractive to bees[7, 14, 20, 108, 244]. The growing plant is a good companion for strawberries, tomatoes, courgettes and most other plants[14, 201, 238]. It is said to deter Japanese beetle and tomato hornworms[238]." [PFAF]

"Seed - sow April/May in situ. The plants quickly develop a stout tap-root and do not transplant successfully[238]. The seed can also be sown in situ in the autumn, this will produce larger plants and earlier flowering[4]. The plant usually self-sows prolifically." [PFAF]

Dynamic Accumlator: of Selenium(Si) and Potassium (K) [DynamicAccumulators]


  1. [E-flora], Accessed Jan 2, 2015; Accessed Jan 5, 2020
  2. [DukePhyto] Accessed Feb 6, 2014
  3. [MTNS] Medical Toxicology of Natural Substances, by Donald G. Barceloux, MD 2008 John Wiley & Sons, Inc.
  4. [] - Material obtained from Plants For A Future Database

Borago Sp. - Borage

"Annual [perennial herb], bristly to rough-hairy. Stem: ascending to erect. Leaf: cauline, ± petioled, ovate to oblanceolate, entire. Inflorescence: cymes, terminal, 2–3-flowered; pedicels ± spreading to pendent in fruit. Flower: calyx deep-5-lobed; corolla rotate to bell-shaped, lobes spreading, throat appendages erect, glabrous; stamens exserted, filament base dilated, anthers adherent around style, separating in age. Fruit: nutlets ± erect, 4, stout, obovoid, irregularly tubercled, exposed stipe-like basal attachment scar, rim of attachment scar thickened.
4 species: southern Europe, northern Africa. (Latin: ancient name)" [Jepson]

Local Species;

  1. Borago officinalis - Common borage [E-flora]


Page last modified on Wednesday, January 6, 2021 7:36 AM