GLA (gamma linoleic acid)

GLA (gamma linoleic acid) is an omega-6 polyunsaturated essential fatty acid.

A small amount of GLA is synthesised in the human body but additional sources are required for optimal growth, development and functioning. The main sources of linoleic acid (which the body converts to GLA and subsequently prostaglandins) are plant based, such as evening primrose oil, black currant seed oil and borage seed oil.

What are its health benefits?

Its by-product prostaglandins are essential for the proper functioning of every cell in the human body.

GLA supplementation may have the following benefits:

  • Assists in pain relief, morning stiffness and joint tenderness in individuals with rheumatoid arthritis
  • Assists in the symptomatic relief associated with diabetic neuropathy (nerve damage) in people diagnosed with type 1 or type 2 diabetes
  • Assisting in the management of eye and heart damage associated with diabetes
  • Assisting in the relief of symptoms (itching and redness) associated with psoriasis and reducing inflammation associated with atopic dermatitis (eczema)
  • Supporting the immune system
  • Assisting in the relief of symptoms associated with premenstrual syndrome (PMS)

Do you have a deficiency?

A deficiency may cause PMS symptoms and affect metabolism. Due to the very nature of its production, GLA may be lacking in many individuals, which makes a good case for supplementation.

Find it in these sources

GLA is found in:

GLA supplements, available in capsule form, are made from evening primrose oil, borage oil and black currant oil.

Recommended dietary allowance (RDA)

For nerve pain due to diabetes, 360 to 480mg of GLA is recommended.

Available data for a variety of conditions, including arthritis, dermatitis and asthma, oral doses have ranged from 500mg to 3g per day. Speak to your Clicks pharmacist about your specific requirements.

The general consensus is that GLA supplementation is safe in adults in doses of up to 2.8g per day for up to a year.


Safety has not been established for pregnancy or breast-feeding, so it’s best avoided in these cases.

It should also be avoided if you have a history of seizures. 

GLA is thought to slow down blood clotting and it may increase the risk of bruising and bleeding in those suffering with bleeding disorders. For this reason, it is advised to stop taking GLA two weeks prior to scheduled surgery.

GLA should be avoided if you’re taking medication to slow blood clotting (blood thinners), such as aspirin and warfarin. It may also interact with phenothiazines (found in certain antipsychotics and antihistamines).

Possible side effects

Possible side effects could include:

  • Soft stools
  • Diarrhoea
  • Belching
  • Intestinal gas

Ensure you discuss dietary supplementation with your Clicks pharmacist to avoid the potential for side effects and adverse interactions with medications.

This medicine has not been evaluated by the Medicines Control Council. This medicine is not intended to diagnose, treat, cure or prevent any disease.

The accuracy of this information was checked and approved by Clicks' pharmacist Waheed Abdurahman in September 2015