Hemp Seed Oil & Gamma-Linolenic Acid (GLA)Hemp seed oil / Gamma-linolenic acid (GLA)
Hemp seed oil is an edible oil pressed from hemp seeds, containing omega-6 linoleic acid and omega-3 alpha-linolenic acid in about a 3:1 ratio, along with small amounts of gamma-linolenic acid (GLA) and stearidonic acid. GLA is an omega-6 fatty acid also abundant in evening primrose oil and borage oil.
Linoleic acid and alpha-linolenic acid are essential fatty acids the body cannot make, serving as building blocks for cell membrane phospholipids and skin stratum corneum lipids (such as ceramides). GLA is converted to dihomo-gamma-linolenic acid (DGLA), which is known to feed into the pathway producing series-1 prostaglandins, which have relatively mild properties. These changes in lipid composition have been studied in relation to skin water loss and dryness markers. Food-grade hemp seed oil uses ingredients that meet standards for psychoactive compounds such as THC.
- In a 20-week randomised, single-blind crossover study of adults with dry, itchy skin, hemp seed oil increased linoleic acid, alpha-linolenic acid and GLA in plasma lipid fractions, and self-rated skin dryness and itchiness improved compared with olive oil (transepidermal water loss reached borderline significance).
- In a 12-week double-blind, placebo-controlled study of 86 healthy adults, hemp seed oil at 2 g/day showed no significant changes in plasma fatty acids, blood lipids (total cholesterol, LDL, HDL, triglycerides) or platelet aggregation markers.
- A Cochrane systematic review pooling studies on GLA-rich evening primrose oil and borage oil for skin symptoms found no meaningful difference from placebo. Evidence for GLA intake on skin markers is limited.
- RCTCallaway J et al. Efficacy of dietary hempseed oil in patients with atopic dermatitis J Dermatolog Treat. 2005. PMID 16019622
- RCTKaul N et al. A comparison of fish oil, flaxseed oil and hempseed oil supplementation on selected parameters of cardiovascular health in healthy volunteers J Am Coll Nutr. 2008. PMID 18460481
- meta-analysisBamford JT et al. Oral evening primrose oil and borage oil for eczema Cochrane Database Syst Rev. 2013. PMID 23633319




