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Borage Oil (Starflower Oil)

Borago officinalis
Evidence Level
Moderate
2 Clinical Trials
5 Documented Benefits
3/5 Evidence Score

Borage oil is cold-pressed from borage seeds (Borago officinalis, also known as 'starflower') — distinguished as having the highest known concentration OF gamma-linolenic acid (GLA, ~20-26%) of any commercial plant oil, surpassing evening primrose (~9%) and black currant (~15%). Used for atopic dermatitis, rheumatoid arthritis, premenstrual syndrome, and other conditions where GLA's anti-inflammatory effects are sought. Critical: contains pyrrolizidine alkaloids (PAs) — hepatotoxic; reputable products are PA-tested/certified PA-free.

Studied Dose 1-3 g borage oil/day (providing 240-720 mg GLA daily); RA trials used up to 1.4 g GLA/day
Active Compound Gamma-linolenic acid (GLA, 20-26% of oil)

Benefits

Highest GLA Concentration of Plant Oils

Distinguishes borage from evening primrose (~9% GLA) and black currant (~15% GLA). Lower volume of borage oil needed for equivalent GLA dose. Cost-effective GLA source per dose.

Supported by Trial 2

Rheumatoid Arthritis Adjunct

Multiple trials (others) show GLA from borage oil (1.4 g/day) reduces joint pain, morning stiffness, and NSAID requirements in RA. Adjunct to standard treatment. Effect smaller than fish oil EPA/DHA but documented.

Supported by Trial 1

Atopic Dermatitis / Eczema (Mixed Evidence)

Earlier trials suggested benefit; larger systematic review of 27 trials found GLA (from borage and evening primrose) not effective for atopic dermatitis. Current consensus: limited/no benefit despite long-standing folk use.

Supported by Trial 2

Premenstrual Syndrome Support

Some evidence for cyclic mastalgia and PMS symptoms. Effects modest; foundational evidence from older trials less robust by modern standards.

Supported by Trial 2

Diabetic Neuropathy Adjunct

Older research suggested GLA may help diabetic neuropathy. Modern evidence less robust; alpha-lipoic acid has stronger evidence for this indication.

Supported by Trial 1, Trial 2

Mechanism of action

1

GLA → DGLA → PGE1 Anti-Inflammatory Pathway

GLA (gamma-linolenic acid) is metabolized via elongase to DGLA (dihomo-gamma-linolenic acid), which produces SERIES-1 prostaglandins (PGE1) — anti-inflammatory, anti-platelet, vasodilatory. Distinguishes from arachidonic acid pathway producing pro-inflammatory PGE2. Mechanism for anti-inflammatory effects.

2

Bypass Delta-6 Desaturase Limitation

Conversion of LA to GLA requires DELTA-6 desaturase — limited in: aging, diabetes, alcohol use, deficiency states. Direct GLA supplementation bypasses this conversion bottleneck. Theoretical advantage in those with reduced conversion capacity.

3

Skin Barrier Lipid Support

GLA contributes to skin barrier lipid composition; theoretical benefit for skin conditions (though clinical evidence limited for eczema).

4

Cytokine Modulation

GLA modulates pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6) via DGLA-derived eicosanoids and direct effects.

Clinical trials

1
Borage Oil for Rheumatoid Arthritis

Clinical trial of borage oil GLA (1.4 g GLA/day) vs placebo in 37 RA patients for 24 weeks.

37 RA patients.

GLA group had significant improvements in joint tenderness, swelling, and morning stiffness. Established borage oil as RA adjunct. Adjunct only — not replacement for DMARDs/biologics.

2
GLA for Atopic Dermatitis — Evidence Review

Evidence review/pooled analysis of 27 clinical trials of borage and evening primrose oil for atopic dermatitis.

Pooled across 27 clinical trials.

GLA not effective for atopic dermatitis. Despite long folk use, clinical trial evidence does not support benefit. Notable example of folk medicine claims not surviving rigorous evaluation.

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated.
Mild GI distress (nausea, soft stools).
Headache rare.
Pyrrolizidine alkaloid (PA) concern — borage plant contains hepatotoxic PAs; reputable products test/certify PA-free; avoid untested products.
Theoretical seizure threshold lowering (older case reports of seizures in epileptics at very high doses).
Bleeding risk theoretical (modest).

Important Drug interactions

Anticoagulants — additive bleeding risk theoretical; minor.
Phenothiazines (chlorpromazine, prochlorperazine) — case reports of seizure threshold lowering; avoid combination.
Anticonvulsants — theoretical seizure risk; consult.
Hepatotoxic medications — pyrrolizidine alkaloid risk amplified; choose PA-tested products.
Pregnancy — limited safety data; PA risk for fetus; avoid without obstetric guidance.
Lactation — PAs may transfer to breast milk; avoid without medical guidance.
Pre-surgery — discontinue 1-2 weeks before.

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Frequently asked questions about Borage Oil (Starflower Oil)

What is borage oil?

Borage oil is one of the richest sources of GLA (gamma-linolenic acid), an omega-6 fatty acid with anti-inflammatory properties. It is used for skin conditions, joint comfort, and women's hormonal support.

What is borage oil good for?

Its GLA is studied for supporting skin health (eczema, dryness), easing joint discomfort, and helping with PMS and menopausal symptoms. It is similar in use to evening primrose oil but higher in GLA.

How much borage oil should I take?

Doses are based on GLA content, often providing around 240 to 1,000 mg of GLA per day. Follow product labeling and take it with food. Give skin and joint goals several weeks.

Is borage oil safe?

It is generally well tolerated. Choose products certified free of pyrrolizidine alkaloids (natural compounds in borage that can harm the liver). It may have mild blood-thinning activity, so check with your doctor if on anticoagulants, and avoid in pregnancy.

What is Borage Oil used for?

Borage Oil is researched primarily for Hair, Skin & Nails and Joint Health. Distinguishes borage from evening primrose (~9% GLA) and black currant (~15% GLA). Lower volume of borage oil needed for equivalent GLA dose. Cost-effective GLA source per dose.

What is the recommended dosage of Borage Oil?

The clinically studied dose is 1-3 g borage oil/day (providing 240-720 mg GLA daily); RA trials used up to 1.4 g GLA/day Always follow the product label and check with a healthcare provider for personal advice.

Is Borage Oil safe, and does it have side effects?

For most healthy adults, Borage Oil is well tolerated at studied doses. Reported effects can include: Generally well-tolerated. Mild GI distress (nausea, soft stools). It may also interact with some medications. Borage Oil is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Borage Oil interact with any medications?

Possible interactions include: Anticoagulants — additive bleeding risk theoretical; minor. Phenothiazines (chlorpromazine, prochlorperazine) — case reports of seizure threshold lowering; avoid combination. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Borage Oil?

NutraSmarts rates the evidence for Borage Oil as Moderate (3 out of 5). It is backed by 2 clinical trials and 6 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(6 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Bamford JT, Ray S, Musekiwa A, van Gool C, Humphreys R, Ernst E. Oral evening primrose oil and borage oil for eczema. Cochrane Database Syst Rev. 2013;2013(4):CD004416. doi: 10.1002/14651858.CD004416.pub2.PubMedUsed to support: Cochrane meta-analysis concluding that oral evening primrose and borage oil are not effective for eczema. Included honestly, it tempers the skin claim despite borage's traditional use.
  2. Henz BM, Jablonska S, van de Kerkhof PC, Stingl G, Blaszczyk M, Vandervalk PG, Veenhuizen R, Muggli R, Raederstorff D. Double-blind, multicentre analysis of the efficacy of borage oil in patients with atopic eczema. Br J Dermatol. 1999;140(4):685-8. doi: 10.1046/j.1365-2133.1999.02771.x.PubMedUsed to support: Multicenter RCT of borage oil for atopic eczema with mixed results, supporting at most a modest effect in some patients. Reflects the uneven skin evidence.
  3. van Gool CJ, Thijs C, Henquet CJ, van Houwelingen AC, Dagnelie PC, Schrander J, Menheere PP, van den brandt PA. 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):943-51. doi: 10.1093/ajcn/77.4.943.PubMedUsed to support: Randomized controlled trial of gamma-linolenic acid for preventing atopic dermatitis, which found no significant prophylactic benefit. Adds balance to the skin evidence.
  4. Zurier RB, Rossetti RG, Jacobson EW, DeMarco DM, Liu NY, Temming JE, White BM, Laposata M. gamma-Linolenic acid treatment of rheumatoid arthritis. A randomized, placebo-controlled trial. Arthritis Rheum. 1996;39(11):1808-17. doi: 10.1002/art.1780391106.PubMedUsed to support: Randomized, placebo-controlled trial in which gamma-linolenic acid (the borage active) reduced rheumatoid arthritis disease activity. Supports the joint and anti-inflammatory use.
  5. Leventhal LJ, Boyce EG, Zurier RB. Treatment of rheumatoid arthritis with gammalinolenic acid. Ann Intern Med. 1993;119(9):867-73. doi: 10.7326/0003-4819-119-9-199311010-00001.PubMedUsed to support: Randomized controlled trial showing gamma-linolenic acid improved rheumatoid arthritis symptoms. Reinforces the joint benefit.
  6. Veselinovic M, Vasiljevic D, Vucic V, Arsic A, Petrovic S, Tomic-Lucic A, Savic M, Zivanovic S, Stojic V, Jakovljevic V. Clinical Benefits of n-3 PUFA and ɤ-Linolenic Acid in Patients with Rheumatoid Arthritis. Nutrients. 2017;9(4):. doi: 10.3390/nu9040325.PubMedUsed to support: Randomized trial reporting clinical benefits of omega-3 and gamma-linolenic acid in rheumatoid arthritis patients. Adds modern support for the joint use.