Evidence-based·Last reviewed May 30, 2026·How we grade evidence

Gamma Linolenic Acid

Fatty-acidGamma-linolenic acidBest with a meal

Useful mainly for people with rheumatoid arthritis seeking an adjunct for joint symptoms.

Quick decision guide

May help most

people with rheumatoid arthritis seeking an adjunct for joint symptoms

Common dosing range

240–720 mg GLA/day (1–3 g/day in RA trials)

When to expect effects

Weeks (4–12 weeks to assess)

Watch out for

use PA-free certified borage oil; may lower seizure threshold

What is it

Gamma-linolenic acid (GLA) is an omega-6 fatty acid with 18 carbons and three double bonds (18:3 omega-6). It is produced in the body from linoleic acid via the enzyme delta-6 desaturase and is also found in supplement oils including borage, evening primrose, black currant, and hemp seed oil.

Is it worth it for you?

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

Worth considering if…

you have rheumatoid arthritis and want an adjunct for joint pain/stiffness
you have diabetic neuropathy and want to try a low-risk option
you can commit to a 2–3 month trial

Probably skip if…

you have epilepsy or a seizure disorder
you want proven relief for eczema, PMS, or asthma
you expect fast results

Evidence at a glance

rheumatoid arthritis

Good Evidence
Effect
Reduced joint pain and morning stiffness
Best fit
people with active RA using GLA alongside standard therapy
Time
Weeks (often 6–12)

diabetic neuropathy

Limited Evidence
Effect
Modest in limited trials
Best fit
people with diabetic peripheral neuropathy (impaired delta-6 desaturase)
Time
Months

Evidence for 2 uses

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

rheumatoid arthritis

Disease adjunct
Good Evidence

Multiple RCTs and a Cochrane review found GLA (often 1–3 g/day from borage or evening primrose oil) reduces RA joint pain and morning stiffness versus placebo. GLA is metabolized to DGLA, which shifts eicosanoid balance toward less inflammatory mediators. Effects build over weeks and are an adjunct to, not a replacement for, standard treatment.

Effect size
Reduced joint pain and morning stiffness
Time to effect
Weeks (often 6–12)
Best fit
people with active RA using GLA alongside standard therapy

Bottom line: A reasonable adjunct that can reduce RA joint symptoms over several weeks.

SourceZurier et al., 1996 — PubMed

diabetic neuropathy

Disease adjunct
Limited Evidence

Some trials report improved nerve-function and symptom measures in diabetic neuropathy with GLA, plausibly because diabetes impairs the enzyme that makes GLA endogenously. Studies are limited in number and size. Evidence is preliminary.

Effect size
Modest in limited trials
Time to effect
Months
Best fit
people with diabetic peripheral neuropathy (impaired delta-6 desaturase)

Bottom line: May modestly help diabetic neuropathy symptoms, but evidence is limited.

SourceWon et al., 2020 — PMCKeen et al., 1993 — PubMed

How it works

GLA is converted in the body to dihomo-gamma-linolenic acid (DGLA), which is the precursor for series-1 prostaglandins (PGE1), considered anti-inflammatory eicosanoids. DGLA also competes with arachidonic acid for enzymes that produce inflammatory mediators, potentially shifting the balance toward less inflammatory products. Research suggests endogenous GLA production via delta-6 desaturase can be impaired by aging, diabetes, atopic conditions, certain genetic variants, and dietary factors. In these conditions, dietary GLA supplementation can help maintain adequate downstream anti-inflammatory eicosanoid production. This is the rationale for using GLA in conditions involving inflammation including arthritis, atopic dermatitis, and certain skin conditions. Clinical evidence varies by indication. GLA has the strongest evidence for rheumatoid arthritis, where multiple trials show reductions in joint symptoms. For atopic dermatitis, evidence is mixed. For diabetic neuropathy, some trials show benefit, possibly because diabetes impairs delta-6 desaturase function. GLA effects on women's health concerns (PMS, mastalgia) have limited rigorous support.

How to take it

1. Typical dose
240–720 mg GLA/day for general use
2. Higher studied dose
1–3 g GLA/day in rheumatoid arthritis trials
3. Timing
with food (fat-soluble); split morning and evening for steady levels
4. With food
with food
5. Split dosing
divide daily dose to maintain levels and reduce GI upset
6. How long to try
4–12 weeks to assess inflammatory-condition effects

What to track

joint pain and morning stiffness (RA)
neuropathy symptoms
GI tolerance
borage source PA-free certification

4 commercial forms

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

Borage oil

Most concentrated GLA source. Choose PA-free certified products.

Highest GLA concentration (20-26%); requires fewer capsules for given GLA dose.

Evening primrose oil

Long history of use, particularly for women's health. Requires more capsules for given GLA dose than borage.

GLA content 8-10%; the most-studied form historically.

Black currant seed oil

Provides GLA plus modest omega-3 content.

GLA content 15-20%; also contains some alpha-linolenic acid (omega-3).

Hemp seed oil

Provides GLA along with other essential fatty acids; not typically used solely for GLA.

Lower GLA content (3-4%); balanced omega-6 to omega-3 ratio.

Safety

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

Common side effects

mild GI upsetsoft stoolsburpingheadache

Serious risks

  • hepatotoxicity risk from pyrrolizidine alkaloids in non-PA-free borage oil

Who should avoid it

  • pregnant women
  • people with epilepsy/seizure disorders (without clinician input)
  • people on anticoagulants (without clinician input)

Pregnancy & breastfeeding

Avoid in pregnancy due to limited safety data and effects on prostaglandin pathways.

Interactions

anticoagulants/antiplateletsModerate

mild antiplatelet effect may increase bleeding risk

anticonvulsants / seizure thresholdModerate

may lower seizure threshold

phenothiazine antipsychoticsModerate

may interact unfavorably

Protocols featuring Gamma Linolenic Acid

Evidence-backed routines where Gamma Linolenic Acid plays a role.

Eczema Support

skin conditions

Atopic dermatitis (eczema) is a chronic, relapsing inflammatory skin disease affecting 10-20% of children and 1-3% of adults. The pathology is a tripod: skin barrier dysfunction (often driven by filaggrin gene mutations), Th2-skewed immune dysregulation, and an altered skin microbiome with reduced diversity and Staphylococcus aureus overgrowth. Flares cycle around triggers — irritants, allergens, stress, infection, dry climate — and conventional treatment is rightly aggressive in moderate-to-severe disease: daily emollients, topical corticosteroids and calcineurin inhibitors (tacrolimus, pimecrolimus), and for refractory or extensive disease, biologics like dupilumab. Supplements occupy a supportive role here. They can blunt systemic inflammation, support barrier function, and nudge immune balance — but they don't replace the topical and systemic backbone. If your eczema is moderate-to-severe, scarring you, disrupting sleep, or unresponsive to good topical care — see a dermatologist. Modern biologics (dupilumab, tralokinumab) have transformed outcomes for adult atopic dermatitis. Supplements work best as one layer of a multi-modal plan that always includes daily emollient routine and trigger management.

Food sources

Borage oil (1 tsp)

Amount
approx 1000 mg providing 200-260 mg GLA
%DV
—

Evening primrose oil (1 tsp)

Amount
approx 1000 mg providing 80-100 mg GLA
%DV
—

Black currant seed oil (1 tsp)

Amount
approx 1000 mg providing 150-200 mg GLA
%DV
—

Hemp seeds (3 tbsp)

Amount
Small amounts of GLA along with other essential fatty acids
%DV
—

Choosing a product

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

Look for…

stated GLA amount (not just total oil)
PA-free certification for borage oil
named oil source (borage/evening primrose/black currant)

Be skeptical of…

eczema/PMS cure claims
anti-inflammatory 'miracle' language
implying it replaces RA medication

Frequently asked questions

What is gamma-linolenic acid?⌄

GLA is an omega-6 fatty acid that the body normally produces from linoleic acid. It is a precursor to anti-inflammatory eicosanoids and is supplemented for inflammatory conditions when endogenous production may be impaired.

Should I take borage or evening primrose oil?⌄

Borage oil is more concentrated in GLA (20-26%) than evening primrose oil (8-10%), so fewer capsules are needed. Choose PA-free certified borage oil. Evening primrose has a longer history of use, especially for women's health.

Does GLA reduce inflammation?⌄

GLA is metabolized to anti-inflammatory eicosanoids in the body. Multiple trials support benefit in rheumatoid arthritis. Effects on other inflammatory conditions are mixed.

How much GLA do I need?⌄

Typical doses for general use are 240-720 mg per day. For inflammatory conditions like RA, 1-3 grams per day has been used in clinical trials.

Can GLA replace omega-3 supplements?⌄

No. GLA is an omega-6 fatty acid with different effects than omega-3 fatty acids (EPA/DHA). Both omega-3s and GLA have anti-inflammatory effects but work through different pathways and may complement each other.

References by claim

rheumatoid arthritis

Zurier et al., 1996 — PubMed (1996) link

diabetic neuropathy

Won et al., 2020 — PMC (2020) link

Keen et al., 1993 — PubMed (1993) link

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Evidence-based·Last reviewed May 30, 2026·Evidence current as of May 30, 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.