Gamma-Linolenic Acid

Gamma-linolenic acid (gamolenic acid, GLA) is an omega-6 fatty acid that the body normally makes from dietary Linoleic Acid. From the early 1980s, a popular theory held that people with Atopic Dermatitis convert linoleic acid to GLA poorly, so taking GLA directly would bypass the block, feed anti-inflammatory prostaglandin pathways and repair the Skin Barrier Dysfunction. GLA-rich seed oils were marketed on that basis: Evening Primrose Oil (a 1 g Efamol capsule holds about 0.08 g GLA and 0.62 g linoleic acid; AAFP 2009), Borage Oil (starflower, the richest common source) and blackcurrant seed oil.

Gamma-Linolenic Acid [part-of] Evening Primrose Oil Gamma-Linolenic Acid [part-of] Borage Oil Linoleic Acid [precedes] Gamma-Linolenic Acid

Strength of evidence: strong evidence of no benefit. The Cochrane review by Bamford et al. (2013) pooled 27 placebo-controlled RCTs with 1,596 adults and children: 19 of evening primrose oil and 8 of borage oil. Neither improved global eczema symptoms more than placebo. Trials that included children were also null: a BMJ trial of borage oil in 140 patients, 69 of them children, found no difference in severity, symptoms or drug use after 12 weeks (Takwale 2003, via Schäfer). In the UK, GLA was once a prescription medicine (Epogam, “for the symptomatic relief of atopic eczema in children and adults”). The MHRA’s predecessor withdrew the licence from 7 October 2002 because the data did not meet the efficacy standard; no safety problem was cited. GLA products remain on sale as food supplements but cannot make medicinal claims.

Cochrane [contradicts] Gamma-Linolenic Acid MHRA [regulates] Gamma-Linolenic Acid

Combination products. GLA from blackcurrant seed oil also appears in combination supplements tested with Fish Oil and Omega-3. In a small triple-blind RCT (Niseteo 2024, 52 children), an omega-3 + blackcurrant GLA + Vitamin D product cut median SCORAD from 42 to 25 over 4 months. Because three ingredients were given together, the trial cannot show that GLA was the active part, and it does not overturn the Cochrane result for GLA alone.

Gamma-Linolenic Acid [relates] Fish Oil and Omega-3

Conflict: [Niseteo et al., Nutrients, 2024] says a supplement containing blackcurrant GLA (with omega-3 and vitamin D) reduced SCORAD and steroid use in 52 children. [Bamford et al., Cochrane, 2013] says oral GLA-rich oils are no better than placebo across 27 RCTs. Unresolved — add to open_questions.

What parents report (evidence: anecdotal). In r/eczema threads on borage and evening primrose oil, users describe softer or better-”hydrated” skin but not clearance of eczema, matching the trial evidence.

Connections

• Evening Primrose Oil — active fatty acid, source: AAFP 2009
• Borage Oil — richest GLA source, source: Cochrane 2013
• Linoleic Acid — metabolic precursor; “conversion defect” theory, source: AAFP 2009
• Cochrane — 27 RCTs, no benefit over placebo, source: Bamford 2013
• MHRA — Epogam licence withdrawn 2002, source: Quackwatch
• Fish Oil and Omega-3 — combined in blackcurrant GLA product, source: Niseteo 2024