Educational information, not medical advice — ask your doctor or midwife.
Borage is a bristly, blue-flowered garden herb, Borago officinalis. German speakers call it Borretsch. Its leaves, flowers and seeds have all been used in European folk practice.
Two very different products share the name. Borage seed oil is a supplement rich in a fat called GLA. Borage leaf and flower are used as food, tea or tincture.
That split matters for safety. Leaf and flower hold pyrrolizidine alkaloids, natural compounds that can harm the liver. Seed oil sold as a supplement is usually made and tested to be free of them.
The evidence verdict is modest. Human trials of borage oil are small and mixed, and the strongest ones are not encouraging. Long traditional use is not proof that borage works, and it is not proof that borage is safe.
If borage seed oil does anything, GLA (gamma-linolenic acid) is the likely reason. Your body turns GLA into signalling fats that help control inflammation, the body's swelling response.
In lab and animal studies, those fats appear to damp inflammation down. Small human trials have measured joint tenderness and skin dryness. The results are too patchy to call the effect proven.
Folk use of the leaf rested on something simpler. The leaf is full of mucilage, a slippery gel, and was thought to soothe a raw throat and chest. That idea has not been tested in modern trials.
The alkaloids in leaf and flower are a hazard, not a benefit. In animals, the liver turns them into reactive products that injure small blood vessels. Repeated exposure is the worry, not one sip.
Most borage sold today is seed oil, in softgel capsules or as a bottled liquid. Labels usually state the GLA content as well as the oil weight.
Older forms are still around. Dried leaf is sold as tea. Fresh young leaves are eaten as a vegetable in parts of Europe.
Flowers decorate salads and summer drinks. Tincture, an alcohol extract of the leaf, turns up in herb shops. Cold-pressed borage oil also appears in skin creams and lotions.
The form drives the risk. Leaf and flower products can carry the liver-toxic alkaloids. Seed oil pressed from cleaned seed usually does not, if the maker tests for it.
If you buy seed oil, look for a clear PA-free claim on the pack. Borage oil also goes rancid easily. Keep it cool and watch the date.
Borage has a long record in European folk practice. Medieval herbalists tied it to courage and good cheer. An old Latin tag ran: I, borage, bring always courage.
Sixteenth-century writers such as John Gerard listed it for melancholy, fever and sore throat. Country use put the leaf into soups, salads and wine cordials.
German tradition knows it as Borretsch. Its cucumber-flavoured leaves are a classic part of Frankfurt green sauce. Seed oil is a modern product, born of twentieth-century interest in GLA.
These records show what people did, not what worked. Chemists later found the liver-toxic alkaloids that older users had no way to see.
Stop taking borage and get medical help if you notice:
Yellow skin or eyes (jaundice), dark urine, or pale stools.
Pain or swelling in the upper right side of your belly, or a belly that swells up quickly.
Lasting nausea, vomiting or deep tiredness with no clear cause.
Unusual bruising, nosebleeds, bleeding gums or black stools.
A seizure, or any sudden blackout. Call emergency services for this.
Tell the doctor exactly which borage product you took and for how long. Bring the pack if you can.
In the UK, EU and US, borage seed oil is sold as an ordinary food supplement. It is not approved as a medicine for any disease.
EU rules set strict limits on pyrrolizidine alkaloids in herbal teas and supplements, and German authorities have long restricted borage leaf products.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
Reviewed by the HealisticMD editorial team How we grade evidence →
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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