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Borage
Caution🐾Borretsch · (Borago officinalis)
Borage family (Boraginaceae)
Description
Bright blue, star-shaped flowers and a fresh, cucumber-like leaf flavour have made borage a favourite kitchen herb — most famously as an ingredient of Frankfurt Green Sauce. The herb and flowers, however, contain liver-toxic pyrrolizidine alkaloids, which led German Commission E to issue a negative monograph in 1992 against internal use of the herb, and food-safety authorities advise keeping total intake very low. In the kitchen, only young leaves and flowers are used, occasionally and in small amounts; regular tea or tincture use is not advised. Borage seed oil is a different matter: largely free of pyrrolizidine alkaloids and rich in gamma-linolenic acid, it is used externally, under clinical study, for atopic dermatitis and dry skin. Historically a flower tea was also considered calming, though this is now discouraged because of the alkaloid content.
CONTRAINDICATED during pregnancy
STRICTLY CONTRAINDICATED. Pyrrolizidine alkaloids cross the placenta and are hepatotoxic — damage to the fetal liver (veno-occlusive disease) is possible. Frankfurt Green Sauce should also not be eaten regularly during pregnancy.
CONTRAINDICATED during breastfeeding
STRICTLY CONTRAINDICATED. PAs pass into breast milk and can cause severe liver damage (hepatic veno-occlusive disease) in the infant. Historically documented infant deaths after maternal PA consumption.
CONTRAINDICATED for children
Strictly avoid internal use of borage herb in children — child liver is particularly sensitive to PA. Also avoid regular consumption in Frankfurt Green Sauce for young children.
Critical drug interactions with:
Hepatotoxische Arzneimittel (Paracetamol-Hochdosis, Methotrexat, Isoniazid, Ketoconazol, Statine, Valproinsäure)
Classic ingredient in Frankfurt Green Sauce and wild-herb salads — cucumber-like flavour. Only young leaves, only occasionally, due to pyrrolizidine alkaloids.
Preparation & dosage
Edible, brilliant-blue flowers as spectacular decoration. PA content of flowers is markedly lower than leaves; still use only in decorative amounts.
Preparation & dosage
Traditional culinary use as aromatic herb with cucumber-like flavour — signature herb of Frankfurt Green Sauce.
Preparation & dosage
Historical folk-medicinal use as a calming, 'heart-strengthening' and diaphoretic tea. No longer recommended today due to pyrrolizidine alkaloids — listed for documentary purposes only.
Preparation & dosage
Borage seed oil is largely PA-free (unlike the herb) and rich in gamma-linolenic acid (GLA). Used externally for atopic dermatitis and dry skin — ingredient of modern skin care.
Preparation & dosage
STRONG WARNING — Borage herb (leaves, flowers, shoots) contains HEPATOTOXIC and potentially CARCINOGENIC pyrrolizidine alkaloids (PA) of the lycopsamine type (lycopsamine, intermedine, amabiline). German Commission E published a NEGATIVE monograph in 1992 — internal use of the herb is REJECTED. The BfR recommends keeping total intake of 1,2-unsaturated PA from all foods below 1 µg per day. CULINARY USE (young leaves in Frankfurt Green Sauce, flowers as garnish): only occasionally and in small amounts. NO TEA, NO TINCTURE as continuous use. Borage SEED OIL is largely PA-free and suitable for external/internal use — provided it is certified PA-free. ASPCA classification (accessed 2026-08-10): toxic to cats.
⏱ Max continuous use: 1 weeks
STRICTLY CONTRAINDICATED. Pyrrolizidine alkaloids cross the placenta and are hepatotoxic — damage to the fetal liver (veno-occlusive disease) is possible. Frankfurt Green Sauce should also not be eaten regularly during pregnancy.
STRICTLY CONTRAINDICATED. PAs pass into breast milk and can cause severe liver damage (hepatic veno-occlusive disease) in the infant. Historically documented infant deaths after maternal PA consumption.
Strictly avoid internal use of borage herb in children — child liver is particularly sensitive to PA. Also avoid regular consumption in Frankfurt Green Sauce for young children.
Drug interactions
Hepatotoxische Arzneimittel (Paracetamol-Hochdosis, Methotrexat, Isoniazid, Ketoconazol, Statine, Valproinsäure)
PAs are activated by hepatic CYP3A4 to reactive pyrroles that damage liver tissue. Concomitant intake of other hepatotoxic substances can lead to additive or synergistic liver damage.
Antikoagulanzien (Warfarin, DOAKs) — bei Borretschsamenöl-Hochdosen
Gamma-linolenic acid (GLA) from borage seed oil can inhibit platelet aggregation and slightly increase bleeding risk; with high oral doses (> 1 g GLA/day) combined with anticoagulants, use caution.
Antiepileptika (Phenothiazine, Trizyklika, Bupropion — krampfschwellensenkende Wirkstoffe)
Isolated case reports describe seizures under high-dose borage seed oil combined with seizure-threshold-lowering drugs — mechanism unclear, caution in epilepsy patients.
Contraindications
- Pregnancy — pyrrolizidine alkaloids cross the placenta and are fetally hepatotoxic.
- Lactation — PAs pass into breast milk; documented infant harm.
- Infants and small children — particular liver sensitivity to PA.
- Pre-existing liver disease (hepatitis, cirrhosis, hepatic veno-occlusive disease).
- Alcohol abuse and concomitant use of hepatotoxic medicines.
- Hypersensitivity to Boraginaceae.
Harvested part: leaves and flowers (summer)
- Time of day:
- Late morning after dew has dried, before flowering. Harvest ONLY young, tender leaves — older ones are too bristly and contain more PA. Due to PA concerns, do not harvest in large amounts, do not dry for long storage; use fresh.
- Drying:
- Fresh use is recommended. If at all: lay out thinly, dry in the shade at max 35 °C. Generally avoid stockpiling due to pyrrolizidine alkaloids.
- Storage:
- 6 months — If dried: airtight, dry, dark — and only very small amounts, as continuous internal use is not recommended.
- Time of day:
- Sunny mornings. Pick freshly opened blue flowers in the morning — they bloom only for a day and close in rain. Remove the small black calyx (with appendages) at the flower base as it tastes bitter. Use fresh — flowers wilt within hours.
- Drying:
- Only decorative; dried flowers quickly lose their bright blue colour and turn greyish. For garnish always prefer fresh flowers. Alternative: freeze in ice cubes — preserves colour and shape for drinks.
- Storage:
- 3 months — Fresh: only a few hours. Frozen in ice cubes: ca. 3 months. Dried (decorative only): airtight, dark, cool.
- Pyrrolizidinalkaloide (Lycopsamin, Intermedin, Amabilin, Supinin, Thesinin)AlkaloidContent: 0.001–0.01 % (Blätter, Sprossspitzen, Blüten)Aerial parts
TOXICOLOGICAL LEAD SUBSTANCE. 1,2-unsaturated PAs of the lycopsamine type — activated in the liver by CYP3A4 to reactive pyrroles causing hepatocellular and sinusoidal endothelial damage (hepatic veno-occlusive disease) and carcinogenic in animal experiments. Highest concentration in young plant parts; markedly lower in flowers and seeds. Refined borage seed oil is largely PA-free.
- Schleimstoffe (saure Polysaccharide, Galactane)MucilageContent: ca. 10–30 %Leaf
Demulcent and mildly expectorant principle — historically the basis for folk-medicinal use in cough and bronchial catarrh. Today replaced by safer mucilage drugs (marshmallow, ribwort plantain).
- GerbstoffeTanninContent: ca. 1–3 %Leaf
Astringent, mildly anti-inflammatory; contribute to folk-medicinal use for mild inflammation of mouth and throat mucosa.
- Mineralstoffe (Kalium, Calcium, Magnesium, Eisen)MineralContent: Asche ca. 14–21 %, davon reich an Kalium und CalciumLeaf
High mineral content — historically valued as a 'blood-cleansing' and 'remineralising' wild vegetable. K/Ca ratio may partly contribute to a mild diuretic effect.
- Gamma-Linolensäure (GLA, C18:3 n-6)Essential oilContent: ca. 17–25 % der Samenöl-FettsäurenSeed
LEAD SUBSTANCE OF SEED OIL. Borage seed oil is one of the richest plant GLA sources (higher than evening primrose). GLA is metabolised to dihomo-gamma-linolenic acid and to inflammation-modulating series 1 prostaglandins — basis of modern use in atopic dermatitis and chronic inflammatory skin conditions. Clinical evidence is mixed.
- KieselsäureMineralContent: Spuren bis ca. 2 %Leaf
Gives the leaves their characteristic bristly hairiness — reason why older leaves are rough and unpleasant.
- [1]MonographKommission E Monographie (NEGATIV): Boraginis herba (Borretschkraut) — Bundesanzeiger Nr. 127 vom 14.07.1992(accessed: 2026-05-19)
- [2]MonographBfR-Stellungnahme Nr. 030/2013: Pyrrolizidinalkaloide in Kräutertees und Tees (aktualisiert)(accessed: 2026-05-19)
- [3]MonographEFSA Scientific Opinion on Pyrrolizidine alkaloids in food and feed (CONTAM Panel), EFSA Journal 2017;15(7):4908(accessed: 2026-05-19)
- [4]MonographPlants For A Future — Borago officinalis L.(accessed: 2026-05-19)
- [5]MonographHeilkräuter-Lexikon — Borretsch (Borago officinalis)(accessed: 2026-05-19)
- [9]MonographASPCA Animal Poison Control — Borage (Borage officinalis)(accessed: 2026-08-10)
- [6]BookHenriette's Herbal Homepage — Borage (Borago officinalis), historical herbals incl. King's American Dispensatory 1898(accessed: 2026-05-19)
- [7]WikipediaWikipedia DE — Borretsch (Borago officinalis)(accessed: 2026-05-19)
- [8]WikipediaWikipedia EN — Borage (Borago officinalis)(accessed: 2026-05-19)
Distribution in Europe
🤝 Permaculture Partners
In your garden, this plant acts as:
✨ Best symbiotic partners
- 🌿 Calendula officinalis Calendula and borage — the dual insect magnet.
- 🌿 Cucurbita pepo Borage attracts pollinators to squash flowers.
- 🌿 Zucchini Borage attracts pollinators to zucchini flowers — more fruits.
- 🌿 Fragaria vesca Borage attracts pollinators to strawberry blossoms and strengthens the plant.
📦 Part of these planting sets:
Source: Helga und Margarete Langerhorst, Mein gesunder Naturgarten (eigene Kuration)