Evidence-based·Last reviewed May 31, 2026·How we grade evidence

Borage

BotanicalBest with a meal

Whole-plant borage — leaves, flowers, aerial-parts extracts — is the part of the plant that carries pyrrolizidine alkaloids (PAs), which are hepatotoxic and genotoxic carcinogens. EFSA and BfR both advise against medicinal use of PA-containing herbs. There is essentially no rigorous human RCT support for borage-leaf preparations, and the safety case alone is enough to skip them. (Note: borage SEED OIL is a different product, see /nutrients/borage-oil.)

Quick decision guide

May help most

Almost no one as a medicinal supplement. Limited culinary use of fresh young leaves/flowers as garnish in small, occasional amounts is a separate (lower) exposure category — but regular tea / tincture / extract use of borage leaves is not recommended.

Common dosing range

No safe medicinal dose is established for borage leaf, flower, or aerial-parts extract due to pyrrolizidine alkaloid content.

When to expect effects

Not relevant — recommended against medicinal use.

Watch out for

Hepatotoxic pyrrolizidine alkaloids (amabiline, lycopsamine, supinine). EFSA/BfR recommend against medicinal use of PA-containing herbs.

Evidence snapshot

Safety (PA hepatotoxicity)Strong (against use)
Anti-inflammatory / 'adrenal' folk useLow
Respiratory / cough folk useLow
Mood / 'adaptogen' marketingLow

What is it

Borage (Borago officinalis) is a herbaceous flowering plant native to the Mediterranean region. While the leaves and flowers have been used traditionally in cooking and herbal medicine, the most studied product is borage seed oil, which is one of the richest natural sources of gamma-linolenic acid (GLA), typically containing 20-26% GLA.

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You're using small amounts of fresh leaves/flowers as an occasional culinary garnish — and you've decided you accept the very low residual PA exposure

Probably skip if…

You're using borage tea, leaf tincture, or aerial-parts extract regularly — EFSA and BfR explicitly advise against this
You're pregnant, breastfeeding, planning pregnancy, or have any liver disease
You're hoping for evidence-based anti-inflammatory or anxiolytic effects — there are essentially no RCTs in whole-plant borage; the GLA you may be after is in the seed OIL, which is a different product
You're already on hepatotoxic medications (acetaminophen at high doses, methotrexate, isoniazid, valproate)
You're a child or feeding it to a child

Evidence at a glance

Traditional anti-inflammatory / 'adrenal tonic' use

Weak Evidence
Effect
No controlled clinical trial evidence in modern terms
Best fit
None — choose borage seed oil if GLA is the goal, or another anti-inflammatory entirely
Time
Not relevant

Cough / respiratory folk use

Weak Evidence
Effect
No controlled clinical trial evidence
Best fit
None — marshmallow root or slippery elm are safer demulcents
Time
Not relevant

Mood / 'natural Prozac' marketing

Weak Evidence
Effect
No controlled clinical trial evidence
Best fit
None
Time
Not relevant

Evidence for 3 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Traditional anti-inflammatory / 'adrenal tonic' use

Supplement benefit
Weak Evidence

Borage leaves and flowers have a long history in European folk medicine as a 'cooling' anti-inflammatory and supposed 'adrenal tonic.' There are essentially no controlled human trials to evaluate these uses, and the PA content makes recurring exposure a poor risk-benefit trade. Any genuine anti-inflammatory benefit attributed to borage in modern supplementation almost certainly comes from the SEED OIL (GLA), which is a separate, better-evidenced, lower-risk product.

Effect size
No controlled clinical trial evidence in modern terms
Time to effect
Not relevant
Best fit
None — choose borage seed oil if GLA is the goal, or another anti-inflammatory entirely
Less likely
Anyone wanting an evidence-based anti-inflammatory supplement

Bottom line: Skip whole-plant borage for inflammation. Borage seed oil is the GLA product worth discussing.

SourceMSKCC About Herbs — Borage — Memorial Sloan Kettering Cancer Center

Cough / respiratory folk use

Supplement benefit
Weak Evidence

Borage leaf tea has folk use for cough and bronchitis (its mucilage gives a soothing demulcent feel). No controlled trials support this versus simpler demulcents like marshmallow root or slippery elm — and those alternatives don't carry pyrrolizidine-alkaloid hepatotoxicity. Skip borage in favour of safer demulcent herbs.

Effect size
No controlled clinical trial evidence
Time to effect
Not relevant
Best fit
None — marshmallow root or slippery elm are safer demulcents
Less likely
Anyone with chronic cough where evaluation by a clinician is warranted

Bottom line: Skip. Use a safer demulcent herb or address the underlying cause of the cough.

SourceMSKCC About Herbs — Borage — Memorial Sloan Kettering Cancer Center

Mood / 'natural Prozac' marketing

Mechanism only
Weak Evidence

Some borage-leaf marketing leans on a folk reputation as an uplift / mood support. There are no controlled trials in depression or anxiety with borage leaves or aerial-parts extracts. The marketing is unsupported and the PA exposure is a real risk for what is at most a placebo effect.

Effect size
No controlled clinical trial evidence
Time to effect
Not relevant
Best fit
None
Less likely
Adults with depression or anxiety needing evidence-based care

Bottom line: Skip. Discuss evidence-based options for mood with a clinician.

SourceMSKCC About Herbs — Borage — Memorial Sloan Kettering Cancer Center

How it works

Borage's primary therapeutic constituent is gamma-linolenic acid (GLA), an omega-6 fatty acid. The body converts GLA to dihomo-gamma-linolenic acid (DGLA) and then to anti-inflammatory series 1 prostaglandins (PGE1). This pathway is normally fed by linoleic acid, but the conversion to GLA can be impaired by aging, diabetes, alcohol, and other factors, making direct GLA supplementation potentially beneficial. Borage leaves and aerial parts also contain mucilaginous compounds, tannins, and small amounts of pyrrolizidine alkaloids (PAs). PAs can be hepatotoxic at sufficient exposure, which has led to regulatory concerns about consuming borage leaves and teas in significant amounts. Borage seed oil intended for supplements is typically processed to remove or minimize PA content.

How to take it

1. Typical dose
No safe medicinal dose of borage leaves, flowers, or aerial-parts extract is established because of pyrrolizidine alkaloid hepatotoxicity. EFSA's PA exposure threshold of 0.024 µg/kg/day for an adult is exceeded by a single serving of unstandardised borage leaf tea in worst-case sampling.
2. Higher studied dose
Not applicable — no validated higher-dose study supports raising whole-plant borage intake above culinary trace amounts.
3. Timing
Not relevant for medicinal use.
4. With food
Not relevant for medicinal use.
5. Split dosing
Not relevant for medicinal use.
6. How long to try
Even short-term use of borage tea or leaf extract carries cumulative PA hepatotoxicity risk. The safer default is to avoid medicinal use entirely.

What to track

If you've used borage leaf tea or tincture for weeks–months, mention it to your clinician and consider asking for liver enzymes (ALT, AST, bilirubin)
Stop immediately and seek care if you develop right-upper-quadrant pain, jaundice, dark urine, or unexplained fatigue

Bottom line: Don't use whole-plant borage medicinally. If you want GLA, use PA-free certified borage seed oil instead.

4 commercial forms

Compare the main delivery options and what they’re best suited for.

Borage seed oil (PA-free certified)

Use this if you want GLA

The seed-oil product is distinct from whole-plant borage and is the GLA source with real (if modest) clinical evidence for rheumatoid arthritis and other conditions. PA-free certified seed oil testing below 0.5–1 µg PA/g is the standard. See /nutrients/borage-oil for the full enriched evidence review.

Absorbed with dietary fat; PA-free certification is the safety key.

Borage leaf tea / dried herb

Not recommended

EFSA and BfR specifically warn against this format because PA content from leaves is much higher than from seeds and is the most common medicinal-use exposure. Skip in favour of safer demulcent herbs (marshmallow root, slippery elm) if you want a soothing tea.

PAs absorbed readily orally; this is the hepatotoxicity-risk format.

Borage leaf tincture / aerial-parts extract

Not recommended

Concentrated alcohol extracts of the leaf and aerial parts deliver the highest PA doses per serving. Skip entirely.

Highest practical PA exposure per dose.

Fresh young leaves / flowers (culinary)

Limited use

Used historically as a 'cucumber-tasting' garnish in salads, summer drinks, and Pimm's-style cocktails. Small occasional amounts of fresh young material are the lowest-PA-exposure use of borage — but if you eat them frequently the exposure adds up.

Lower PA load than dried/extracted preparations; not a guaranteed safe ongoing exposure.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

GI upsetskin contact dermatitis (rare; leaf hairs can be irritating)

Serious risks

Who should avoid it

Pregnancy & breastfeeding

Avoid whole-plant borage in pregnancy and breastfeeding. Pyrrolizidine alkaloids cross the placenta and transfer into breast milk; documented cases of infant liver injury exist for PA-containing herbs. This contraindication is firm regardless of how 'natural' the product is marketed as.

SourceEFSA 2017 statement on pyrrolizidine alkaloids in food — European Food Safety Authority

Bottom line: Don't use borage leaves, flowers, or aerial-parts extract medicinally. The PA hepatotoxicity risk is real and the clinical-benefit evidence is essentially zero.

Interactions

hepatotoxic medications (methotrexate, isoniazid, high-dose acetaminophen, valproate, amiodarone)Major

Additive hepatotoxicity. PAs cause sinusoidal obstruction / veno-occlusive disease independent of typical drug-induced liver injury mechanisms.

SourceMSKCC About Herbs — Borage — Memorial Sloan Kettering Cancer Center
alcoholModerate

Both burden the liver. Repeated combined exposure increases PA-related hepatotoxicity risk.

SourceMSKCC About Herbs — Borage — Memorial Sloan Kettering Cancer Center
warfarin / antiplatelet drugsMinor

Extrapolated from GLA-containing borage seed oil — minor antiplatelet effect possible in leaf preparations, though the GLA content is much lower than seed oil.

anticonvulsants (phenytoin, carbamazepine, valproate)Minor

Extrapolated from seed-oil case reports of seizure-threshold modulation. Plus valproate hepatotoxicity is additive with PA hepatotoxicity.

Food sources

Fresh borage leaves (young) — culinary garnish

Amount
1–2 small leaves — small occasional culinary use only
%DV
—

Borage flowers — culinary garnish

Amount
A few blue flowers — small occasional culinary use only
%DV
—

Borage seed oil (supplement — different product)

Amount
1 g softgel (~240 mg GLA) — see /nutrients/borage-oil
%DV
—

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

If you're shopping for borage at all, you almost certainly want borage SEED OIL — labelled with PA-free certification (<0.5–1 µg PA/g)
If a product is labelled 'borage leaf,' 'borage aerial parts,' 'borage herb,' or 'Borago officinalis aerial parts' — that's the PA-containing material; choose something else
For fresh culinary use, young leaves and flowers in small occasional amounts are the lowest-PA exposure category — but it's still a regular ongoing risk to factor in
Reputable supplement brands have removed whole-plant borage products from their lines following EFSA / BfR PA recommendations

Be skeptical of…

'Adrenal tonic' / 'natural cortisol support' — no controlled human data
'Anti-inflammatory tea' for chronic conditions — you'll get more from PA-free seed oil GLA if anti-inflammation is the goal
'Liver detox' marketing — borage leaves potentially injure the liver; this claim is the opposite of accurate
'Safe because natural / used for centuries' — PA hepatotoxicity is mechanism-specific and cumulative, regardless of natural origin
Tea blends that hide borage leaf in proprietary 'wellness' formulations without ingredient disclosure

Frequently asked questions

How is borage seed oil different from evening primrose oil?⌄

Both provide GLA, but borage seed oil has a much higher GLA concentration (20-26% vs ~10% in evening primrose), meaning smaller doses are needed. Borage carries pyrrolizidine alkaloid concerns that evening primrose does not.

Are borage leaves safe to eat?⌄

Small amounts as garnish are traditional and probably safe. Daily consumption of large amounts of leaves or borage tea is discouraged due to pyrrolizidine alkaloid content and potential liver toxicity.

Will borage seed oil help my arthritis?⌄

Studies show benefit in rheumatoid arthritis at GLA doses of 1.4-2.8 g/day (equivalent to several capsules of borage oil). Effects develop over weeks. Discuss with your rheumatologist.

Can I take borage oil with my blood thinner?⌄

Borage oil may have additive antiplatelet effects. Discuss with your clinician; bleeding risk should be monitored.

How do I know if my borage oil is safe?⌄

Look for products certified as PA-free or 'pyrrolizidine alkaloid-free.' Reputable manufacturers process the oil to remove these toxins.

References by claim

Safety

EFSA 2017 statement on pyrrolizidine alkaloids in food — European Food Safety Authority (2017) link

BfR (Germany) — pyrrolizidine alkaloid recommendations — Bundesinstitut für Risikobewertung (2024) link

Traditional anti-inflammatory / 'adrenal tonic' use

MSKCC About Herbs — Borage — Memorial Sloan Kettering Cancer Center (2024) link

Other references

Loizzo et al., 2008 (phytochemistry) — Pharmaceutical Biology (2008) link

Borage (Borago officinalis) on Wikidata — Wikidata link

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Evidence-based·Last reviewed May 31, 2026·Evidence current as of May 31, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.