Arachidonic Acid
Also known as ARA, 20:4 n-6
Arachidonic acid is a long-chain omega-6 fat the body makes from linoleic acid and also gets from meat, eggs, and fish. It is a major building block of cell membranes and the source of signaling molecules involved in inflammation, immunity, and muscle repair.
Why it matters
What it does in your body
- Building block of cell membranes, especially in the brain
- Source of signaling molecules for inflammation and immunity
- Supports muscle growth and repair signaling
- Important for infant growth and development
Intake guidance
How much you need
There is no intake target for arachidonic acid, because the body makes it from the essential omega-6 linoleic acid. It also comes directly from animal foods, so both routes keep levels adequate without a dietary requirement.
What affects it
What affects your intake
Body's own production
Healthy adults make arachidonic acid from linoleic acid, so diet is not limiting.
Animal food intake
Meat, poultry, eggs, and fish provide preformed arachidonic acid.
Balance with omega-3
Omega-3 fats compete with arachidonic acid, which is part of how they temper inflammation.
In practice
Good to know
Good to know: arachidonic acid gets a bad reputation as pro-inflammatory, but it is essential for brain structure, immune defense, and even muscle repair, and the body tightly regulates it. It is sold as a niche bodybuilding supplement to enhance training adaptations, with limited evidence. For nearly everyone, the body and a normal diet supply the right amount.
Where to get it
Best food sources
The bottom line
Arachidonic acid is a self-made and food-supplied omega-6 essential to cell membranes and signaling. There is no dietary target, and supplements are a niche, unproven use.
Track arachidonic acid automatically
Arachidonic Acid is one of the 92 nutrients Vora reads from a photo of your meal, so you can see where you stand without weighing or logging by hand.
Sources and method
The classification, roles, and guidance on this page come from the references below, drawing on the Institute of Medicine (now the National Academies) Dietary Reference Intakes and reputable nutrition science.
- Institute of Medicine (2005), Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
- USDA FoodData Central
This page is for general education, not medical advice. Reference intakes are population averages for healthy people and do not replace guidance from your doctor or a registered dietitian, especially if you are pregnant, managing a health condition, or considering supplements.