About GLA (Omega-6)
An omega-6 fatty acid and precursor to anti-inflammatory eicosanoids (via DGLA). Evidence is indication-dependent. Rheumatoid arthritis: two placebo-controlled RCTs (Leventhal 1993, Annals of Internal Medicine; Zurier 1996, Arthritis & Rheumatism) at 1.4–2.8 g/day showed clinically meaningful reductions in tender and swollen joints over 6 months. Diabetic peripheral neuropathy: a multicenter RCT (Keen 1993) at 240–480 mg/day for 6–12 months improved nerve-function and symptom scores. Evidence for the popular skin/eczema use is negative (Cochrane found no benefit), as is PMS/mastalgia. Not an essential nutrient — the body makes GLA from linoleic acid, so no RDA.
What GLA (Omega-6) supports
- May ease rheumatoid arthritis joint symptoms at high dose (RCT evidence)
- May reduce diabetic nerve-pain symptoms (RCT evidence)
How much GLA (Omega-6) to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
240–1000
mg
Pure GLA. Diabetic neuropathy benefit from ~240–480 mg/day; rheumatoid arthritis RCTs used higher 1.4–2.8 g/day. Distinct from its oil sources (evening primrose ~8–10% GLA, borage ~20–26%), scored separately.
Clinical evidence
Moderate clinical evidence. Positive placebo-controlled RCTs for rheumatoid arthritis (high dose) and diabetic neuropathy; Cochrane found no benefit for eczema
Reference