Black Currant Seed Oil
Black currant seed oil is a gamma-linolenic acid (GLA) source — about 15–17% GLA by weight, in between evening primrose (~8–10%) and borage (~20–24%). It's also notable for containing alpha-linolenic acid and a small amount of stearidonic acid, giving it a more balanced omega-6/omega-3 profile than the other GLA oils. Cochrane reviews group it with borage and EPO for rheumatoid arthritis (modest benefit) and atopic dermatitis (no benefit). No pyrrolizidine alkaloid concern.
Quick decision guide
May help most
Adults with rheumatoid arthritis seeking a GLA-source adjunct to standard DMARDs/biologics, who prefer black currant for the absence of borage's PA concern or want the additional ALA / SDA content.
Common dosing range
2–6 g black currant seed oil per day delivering 300–1,000 mg GLA. RA trials used 2 g GLA/day (~12 g BSO/day, a high capsule count). Most everyday supplement use targets 300–600 mg GLA/day.
When to expect effects
8–12 weeks minimum to assess RA symptom change; 6 months for maximum effect.
Watch out for
High doses mean a lot of capsules. Bleeding-risk theoretical with anticoagulants. Cochrane has rejected the eczema use.
Evidence snapshot
What is it
Black currant seed oil is cold-pressed from the seeds of Ribes nigrum, the European black currant. It is notable for its high content of gamma-linolenic acid (GLA, an omega-6 fatty acid) along with alpha-linolenic acid (an omega-3) and stearidonic acid, making it one of the few oils providing a balanced array of essential fatty acids.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
Rheumatoid arthritis (adjunct) Good Evidence | Reduced tender/swollen joint counts and morning stiffness at GLA 2–2.8 g/day over 24 weeks; modest effect size | Adults with RA on stable DMARD/biologic therapy seeking a well-tolerated adjunct; willing to commit to 6 months at high-capsule-load doses | 8–12 weeks for early signs; 6 months for maximum effect |
Atopic dermatitis (eczema) Mixed Evidence | No benefit vs placebo for GLA-rich oils in pooled RCT data | None — the Cochrane review effectively closed this question | Not relevant — no benefit shown |
Cardiovascular biomarkers Mixed Evidence | Inconsistent; no clinically meaningful biomarker shifts at usual supplement doses | None as a primary cardiovascular strategy | Not established |
PMS / cyclical mastalgia Mixed Evidence | Inconsistent; not significantly better than placebo in modern pooled reviews | Adults wanting a low-risk 3-cycle trial for cyclic breast tenderness | 2–3 menstrual cycles to assess |
Rheumatoid arthritis (adjunct)
- Effect
- Reduced tender/swollen joint counts and morning stiffness at GLA 2–2.8 g/day over 24 weeks; modest effect size
- Best fit
- Adults with RA on stable DMARD/biologic therapy seeking a well-tolerated adjunct; willing to commit to 6 months at high-capsule-load doses
- Time
- 8–12 weeks for early signs; 6 months for maximum effect
Atopic dermatitis (eczema)
- Effect
- No benefit vs placebo for GLA-rich oils in pooled RCT data
- Best fit
- None — the Cochrane review effectively closed this question
- Time
- Not relevant — no benefit shown
Cardiovascular biomarkers
- Effect
- Inconsistent; no clinically meaningful biomarker shifts at usual supplement doses
- Best fit
- None as a primary cardiovascular strategy
- Time
- Not established
PMS / cyclical mastalgia
- Effect
- Inconsistent; not significantly better than placebo in modern pooled reviews
- Best fit
- Adults wanting a low-risk 3-cycle trial for cyclic breast tenderness
- Time
- 2–3 menstrual cycles to assess
Evidence for 4 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
Rheumatoid arthritis (adjunct)
Disease adjunctThe Leventhal 1994 RCT (37 RA patients, 2.8 g/day GLA from BSO for 24 weeks) and Watson 1993 trial (38 patients, ~2 g/day GLA from 10.5 g BSO for 24 weeks) both reported significantly improved disease activity vs placebo: fewer tender and swollen joints, less morning stiffness. The 2011 Cochrane review grouped GLA-rich oils (EPO, borage, blackcurrant) together and concluded moderate evidence supports modest reductions in RA symptoms at GLA ≥1.4 g/day for 6 months. Modern biologics dramatically outperform any GLA effect — BSO is a low-risk adjunct, not a replacement.
Bottom line: Real but modest. Capsule load is the practical drawback. Borage at the same GLA dose works the same way with fewer capsules.
Atopic dermatitis (eczema)
Supplement benefitThe 2013 Cochrane review of 27 RCTs (1,596 participants) found neither evening primrose oil nor borage oil was more effective than placebo for atopic eczema. While blackcurrant seed oil specifically wasn't pooled, it shares the same GLA-precursor mechanism and the same conclusion is reasonably extrapolated. Side effects were mild and similar between groups.
Bottom line: Don't take blackcurrant seed oil for eczema. Topical therapy and modern systemic options have much better evidence.
Cardiovascular biomarkers
Supplement benefitSmall studies have looked at BSO effects on blood pressure, lipids, and inflammatory markers, with inconsistent results. The alpha-linolenic acid content is too modest to substitute for dedicated omega-3 sources (flax, fish oil) and the GLA dose typical of supplement use is far below the RA-active range.
Bottom line: Not a cardiovascular supplement. Use flax or fish oil for omega-3 needs.
PMS / cyclical mastalgia
Supplement benefitGLA oils — especially evening primrose — have a long history of use for cyclic breast tenderness and PMS. Modern systematic reviews don't find consistent benefit beyond placebo. Plausible prostaglandin mechanism, weak clinical evidence. Black currant seed oil hasn't been studied separately for this use.
Bottom line: Plausible but unproven. Don't expect dramatic effects.
How it works
How to take it
What to track
Bottom line: For RA: high-dose (~10 g BSO/day) for 6 months. For everyday use: 1–2 g/day. If you can tolerate a higher GLA dose with fewer capsules, borage is more efficient per pill.
4 commercial forms
Compare the main delivery options and what they’re best suited for.
Black currant seed oil softgels (cold-pressed)
Standard formMost common consumer form. Typically 500 mg–1 g per softgel, delivering ~75–170 mg GLA each. Cold-pressed preserves GLA; light- and air-tight packaging matters.
Standard delivery; oil quality varies more than form.
Liquid black currant seed oil
Higher dose per servingSold in dark glass bottles; one teaspoon delivers ~700 mg–1 g of GLA. Less common than softgels. Must be refrigerated after opening; goes rancid quickly.
Same as softgel; storage matters more.
Borage oil (20–24% GLA)
Higher-GLA alternativeMore concentrated GLA per gram of oil, so fewer capsules needed for the same dose. BUT contains pyrrolizidine alkaloids unless certified PA-free. Choose only PA-free certified products. Cross-references the borage page for the safety detail.
More efficient per softgel; PA-free certification mandatory.
Evening primrose oil (8–10% GLA)
Lower-GLA alternativeLess concentrated GLA than BSO. Requires more capsules for the same dose. No PA concern. Bamford 2013 found it equally ineffective for eczema and similar overall clinical profile.
Equivalent on a per-mg-GLA basis; just more pills.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Theoretical bleeding risk at high doses combined with anticoagulants or antiplatelets — discuss with prescriber.
Seizure-threshold concerns (theoretical, extrapolated from EPO data) — caution in people with epilepsy on phenothiazines.
Who should avoid it
- People on warfarin or aggressive antiplatelet therapy without prescriber coordination.
- People with epilepsy on phenothiazines (theoretical seizure-threshold lowering, extrapolated from EPO data).
- Pregnant or breastfeeding people — insufficient safety data.
- Anyone using it for atopic eczema — Cochrane evidence is negative.
Pregnancy & breastfeeding
Safety in pregnancy and lactation has not been adequately studied. Avoid as a supplement; small dietary amounts (e.g., black currant fruit) are not a concern.
Bottom line: Generally well-tolerated. Main practical issue is capsule load at RA-active doses. Avoid if pregnant or on aggressive anticoagulation without medical supervision.
Interactions
GLA oils can modestly reduce platelet aggregation. At supplement doses the bleeding risk is theoretical, but high doses (RA-active range) warrant prescriber coordination.
Case reports with evening primrose oil have suggested seizure-threshold lowering when combined with phenothiazines. Extrapolation to other GLA oils is theoretical.
GLA shifts eicosanoid synthesis in the same direction as NSAIDs target. Combination is not contraindicated and may be additive in RA, but track for additive GI effects.
Food sources
| Food | Amount | %DV |
|---|---|---|
| Black currant seed oil (supplement only) | 1 g (~150–170 mg GLA) | — |
| Black currant berries (fresh fruit) | 100 g (negligible GLA — most GLA is in the seed oil) | — |
| Evening primrose oil (alternative source) | 1 g (~80–100 mg GLA) | — |
| Borage seed oil (alternative source) | 1 g (~200–240 mg GLA) | — |
| Hemp seed oil (small amounts of GLA) | 1 Tbsp (~50–100 mg GLA) | — |
| Spirulina (trace GLA from algae) | 1 g (~10–15 mg GLA) | — |
Black currant seed oil (supplement only)
- Amount
- 1 g (~150–170 mg GLA)
- %DV
- —
Black currant berries (fresh fruit)
- Amount
- 100 g (negligible GLA — most GLA is in the seed oil)
- %DV
- —
Evening primrose oil (alternative source)
- Amount
- 1 g (~80–100 mg GLA)
- %DV
- —
Borage seed oil (alternative source)
- Amount
- 1 g (~200–240 mg GLA)
- %DV
- —
Hemp seed oil (small amounts of GLA)
- Amount
- 1 Tbsp (~50–100 mg GLA)
- %DV
- —
Spirulina (trace GLA from algae)
- Amount
- 1 g (~10–15 mg GLA)
- %DV
- —
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
How is black currant seed oil different from evening primrose oil?⌄
Both contain GLA, but black currant seed oil also has omega-3 (alpha-linolenic acid) and stearidonic acid. Evening primrose oil has higher GLA concentration (~10%) vs black currant (~14% GLA but with more omega-3).
Will black currant seed oil help my eczema?⌄
Some studies show modest improvements. It is not a quick fix and effects develop over weeks of regular use.
Is black currant seed oil the same as the berries?⌄
No. The berries are rich in vitamin C and anthocyanins; the seed oil specifically provides fatty acids. Both have health benefits but different mechanisms.
Can black currant seed oil affect blood clotting?⌄
GLA-rich oils can have mild antiplatelet effects. Discuss with a clinician if you take anticoagulants or have bleeding disorders.
How should I store black currant seed oil?⌄
Polyunsaturated oils are prone to oxidation. Store in dark containers in the refrigerator after opening. Softgels are protected and more stable.
References by claim
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Coming to App StoreDisclaimer: 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.