Cod liver oil delivers three nutrients that directly support skin health: omega-3 fatty acids (EPA and DHA), natural vitamin A (retinol), and vitamin D. Taking it consistently, either as a liquid or capsule, can improve skin hydration, reduce inflammation, and support the cell turnover that gives skin a healthy glow. Most people notice visible changes after about 12 weeks of daily use.
Why Cod Liver Oil Works for Skin
What sets cod liver oil apart from regular fish oil is its combination of omega-3s with naturally occurring vitamins A and D. Each of these nutrients affects your skin through a different pathway, and together they address several root causes of dull, dry, or uneven skin.
Omega-3 fatty acids, particularly DHA, increase the production of filaggrin, a protein your skin cells need to form a strong, moisture-retaining barrier. EPA influences ceramide levels in the skin. Ceramides are the lipids that act like mortar between your skin cells, sealing in hydration and keeping irritants out. Animal studies show that omega-3 supplementation decreases transepidermal water loss (the rate at which moisture escapes through your skin) and increases measurable hydration. In one small human study, women who consumed omega-3-rich oil daily experienced a 39% increase in skin hydration after 12 weeks.
The vitamin A in cod liver oil is preformed retinol, the same family of compounds found in prescription retinoids. Once absorbed, your body converts retinol into retinoic acid, which speeds up skin cell turnover and stimulates collagen production. Research from Oregon State University’s Linus Pauling Institute found that retinoic acid can increase collagen formation by up to 80% compared to baseline. It also blocks enzymes that break down collagen after sun exposure, reducing the kind of damage that makes skin look dull and aged over time.
Vitamin D rounds out the trio by calming inflammatory responses in the skin. It suppresses several pro-inflammatory signaling molecules that contribute to redness, irritation, and uneven texture. It also supports keratinocyte differentiation, the process by which new skin cells mature properly and move to the surface, which is essential for smooth, luminous-looking skin.
Oral Supplementation vs. Topical Use
The most effective and well-studied way to use cod liver oil for skin is to take it orally. Swallowing it as a liquid or capsule allows the omega-3s, vitamin A, and vitamin D to enter your bloodstream and reach skin cells from the inside out. Oral omega-3 supplementation has shown benefits for hydration, acne, atopic dermatitis, and wound healing in burn patients.
Topical application of omega-3 fatty acids is a newer area of research. Early lab and skin-model studies show promise: topical omega-3s have improved skin barrier function, reduced UV-induced inflammation and hyperpigmentation, eased dry skin and itching from dermatitis, and accelerated wound healing. No studies have reported skin irritation or adverse reactions from topical use. However, clinical trial data for applying omega-3s directly to skin remains limited, and there’s no consensus on the best concentration or delivery method. If you want to try applying cod liver oil directly, patch test on a small area of skin first, since the oil has a strong odor and heavy texture that may not suit daily facial use.
For most people, oral supplementation is the more practical and better-supported approach.
How to Take It
Cod liver oil comes in two forms: liquid and softgel capsules. Liquid versions let you adjust your dose more easily and are absorbed slightly faster, but many people prefer capsules to avoid the taste. Either form works. Take your dose with a meal that contains some fat, since vitamins A and D are fat-soluble and absorb better alongside dietary fat.
A standard serving is about one teaspoon (5 ml) of liquid or one to two capsules, depending on the brand. The exact amounts of vitamin A, vitamin D, EPA, and DHA vary between products, so check the label. The nutrient you need to watch most carefully is vitamin A. The tolerable upper intake level for preformed vitamin A in adults is 3,000 mcg (10,000 IU) per day. Going above this consistently raises the risk of liver problems and, for pregnant women, birth defects. If you’re already taking a multivitamin or eating liver regularly, add up your total vitamin A intake before starting cod liver oil.
Consistency matters more than dose. Skin cells take roughly four to six weeks to cycle from the deepest layer to the surface, and building up omega-3 levels in your cell membranes takes time. Plan on at least 12 weeks of daily use before judging results.
Choosing a Quality Product
Because cod liver oil comes from fish liver, which concentrates both nutrients and contaminants, purity matters. Mercury content in dietary supplements should not exceed 0.10 mg/kg. Look for brands that display third-party testing results on their label or website. Organizations like the International Fish Oil Standards (IFOS) program or NSF International test for mercury, PCBs, and oxidation levels. A product that lists specific EPA and DHA amounts per serving, rather than just “fish oil blend,” is generally more transparent about what you’re getting.
Store liquid cod liver oil in the refrigerator after opening and use it within the timeframe listed on the bottle. Omega-3 oils oxidize when exposed to heat, light, and air, and rancid oil can cause digestive upset and may lose some of its benefits.
What It Can and Can’t Do
Cod liver oil is genuinely useful for improving skin hydration, supporting collagen production, and calming low-grade inflammation that contributes to dullness and uneven tone. These are the building blocks of what most people mean by “glowing skin.” It can also help with inflammatory skin conditions like acne and eczema by reducing the immune overreaction driving those flare-ups.
There are limits, though. If you’re hoping it will clear psoriasis, the evidence is mixed at best. A meta-analysis of 13 randomized controlled trials involving 625 participants found that fish oil supplementation did not significantly reduce psoriasis severity scores. Five of the 13 trials reported benefits, but the other eight found fish oil performed no better than a placebo.
Cod liver oil also won’t override the effects of chronic dehydration, poor sleep, excessive sun exposure, or smoking. It works best as one part of a broader routine that includes sun protection, adequate water intake, and a diet with enough protein and antioxidants to support skin repair. Think of it as filling specific nutritional gaps that your skin needs to function at its best, not as a standalone miracle treatment.
Who Should Be Cautious
Pregnant women or those planning to become pregnant should be especially careful about vitamin A intake. Experts advise against exceeding 3,000 mcg RAE (10,000 IU) of preformed vitamin A daily during pregnancy due to the risk of birth defects. Some cod liver oil products contain a substantial portion of this limit in a single serving.
If you take blood-thinning medication, omega-3 fatty acids can have a mild blood-thinning effect at higher doses. Anyone on anticoagulants should discuss cod liver oil with their prescriber before starting. People already taking vitamin D supplements should also check their combined intake, since excessive vitamin D can cause calcium buildup over time.