Astaxanthin: Does It Really Help Tired Eyes?

What is astaxanthin?

Astaxanthin is the red carotenoid that gives salmon flesh and shrimp and crab shells their color. Most astaxanthin in supplements comes from a freshwater microalga called Haematococcus. When stressed by strong sunlight or a lack of nutrients, this alga protects itself by producing large amounts of astaxanthin and turning red. The dried, extracted product is sold as "Haematococcus extract."

It belongs to the same carotenoid family as lutein and zeaxanthin, but it plays a different role in the eye and has a different approved claim in Korea. Lutein builds up in the macula as pigment, while astaxanthin is approved in connection with eye fatigue.

What claim does Korea's MFDS allow?

The approved claim for Haematococcus extract is that it "may help reduce eye fatigue." It was first approved as an individually recognized ingredient in 2007, became a standard listed ingredient in 2010, and was re-evaluated in 2024.

Online ads often call astaxanthin "the king of antioxidants" and promote it for skin aging, fatigue recovery, muscle recovery, and blood vessel health. Strong antioxidant activity has indeed been seen in lab and animal studies, but these effects have not been proven in people, and none of them is an approved claim in Korea. As a health functional food, the only benefit you can count on is the one for eye fatigue.

How strong is the evidence for eye fatigue?

Research on astaxanthin and eye fatigue has mostly been done in Japan, in people who spend long hours looking at computer or phone screens (VDT workers). The main studies:

• Nagaki et al., 2002: VDT workers took 5 mg a day for 4 weeks. Their accommodation (the ability to focus up close) improved and complaints of eye fatigue decreased. This was a small pilot study.
• A 6 mg/day, 4-week double-blind trial: Accommodation improved significantly compared with placebo, but fewer than 50 people in total were analyzed across both groups.
• Sekikawa et al., 2023 (Journal of Clinical Biochemistry and Nutrition): 60 healthy adults took 9 mg a day for 6 weeks. Overall there was no clear difference, but in those aged 40 and over, it reduced the drop in visual function after screen work. The study was funded by an ingredient company.

So there is some evidence that astaxanthin may help with eye fatigue, but the studies are mostly small, short, and funded by ingredient makers. How much difference people notice also varies widely. There is no evidence that it prevents eye diseases such as macular degeneration or cataracts.

How much astaxanthin per day?

Korea's MFDS standard is 4–12 mg of astaxanthin a day. A Korean pharmacy news outlet (Dailypharm) reported that, following the 2024 re-evaluation, the lower limit is to be raised to 6 mg (6–12 mg), but at the time of writing we could not confirm when the revised standard takes effect. When comparing products, go by "astaxanthin ○○ mg", not "Haematococcus extract ○○ mg." Most products on the market provide about 6 mg a day.

The studies above generally judged results after 4 weeks or more of steady use. Rather than expecting results in a few days, it is more realistic to try it for about a month before deciding.

When to take astaxanthin

Astaxanthin is also fat-soluble, so it absorbs better right after a meal than on an empty stomach. You can take it after the same meal as lutein and omega-3. To see all your supplements laid out by time of day, try the supplement schedule.

Can you take lutein and astaxanthin together?

Yes. The two have different approved claims (lutein for macular pigment density, astaxanthin for eye fatigue), which is why "lutein + astaxanthin" combination products are common. Just check two things:

• Doubling up: Adding a single-ingredient product to a combination product can easily push you over the daily amount for each (20 mg of lutein, 12 mg of astaxanthin).
• Matching your goal: If you are concerned about macular pigment declining with age, lutein and zeaxanthin fit; if your eyes tire easily from long screen time, astaxanthin fits. For more on lutein, see our lutein and zeaxanthin article.

Side effects and precautions

• Your skin may temporarily turn yellowish or orange: This MFDS warning applies to large amounts and fades when you cut back.
• If you are being treated for a condition or take medication: Drug interactions with astaxanthin have not been studied enough. If you take blood pressure drugs or anticoagulants, check with your doctor or pharmacist.
• Pregnant or breastfeeding women: Safety data are lacking, so consult a professional before taking it.
• Shellfish allergy: Haematococcus-derived astaxanthin comes from algae, but some products also contain astaxanthin from shellfish such as krill oil, so check the ingredient list.

Getting astaxanthin from food

It is found in red-fleshed fish such as salmon, trout, and sea bream, in shrimp, crab, and lobster, and in salmon roe. Food contains only small amounts, though, so reaching the 6 mg a day used in studies from food alone is difficult. Red-fleshed fish are also a source of omega-3, so eating fish about twice a week does more for overall eye health.

What to check before supplements

Eye fatigue has many possible causes, including long screen time, dry eye, the wrong glasses prescription, and age-related farsightedness. Before choosing a supplement, check the following:

• The 20-20-20 rule: Every 20 minutes, look at something 20 feet (about 6 m) away for 20 seconds to rest your eyes' focusing muscles.
• Blinking and humidity: You blink less when looking at a screen, so your eyes dry out easily. Blink deliberately and keep indoor air from getting too dry.
• Your glasses prescription: If close-up text has been getting blurry and your eyes tire easily since your 40s, it may be presbyopia. Have your vision checked by an eye doctor.
• Pain, redness, or vision loss: This may be more than simple fatigue, so see an eye doctor before trying supplements.

The bottom line

Astaxanthin is a red carotenoid from Haematococcus algae, and Korea's MFDS recognizes its claim to "help reduce eye fatigue." The supporting studies are mostly small and short, so it is wise not to expect too much, but if you spend long hours at a screen, you could try 4–12 mg a day right after a meal for about a month and see. It plays a different role from lutein, so you can take both; just watch for doubling up and check your medications.