Antioxidant · Astaxanthin

Astaxanthin: two placebo-controlled trials — one has 23 people, the other mixed it with collagen

This is swallowed. In the 2018 trial (23 people, 10 weeks) the threshold for UV redness rose above placebo, but FUJIFILM supplied both the funding and the authors. In the 2014 trial (44 people, 12 weeks) elasticity and water loss improved, but it was given together with collagen hydrolysate. And in that same trial, UV-induced DNA damage did not differ.

Last checked Sep 21, 2026

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What it is: The pigment that makes microalgae, salmon and shrimp red. A carotenoid antioxidant.
What it is used for: Mostly sold as capsules to swallow. It also goes into topicals, but both trials below were swallowed.
How it is said to work: It is said to cut reactive oxygen species and so lessen the damage UV leaves behind.

There are no numbers and no citations in this box. What has been established, and how far, is below.

At a glance

In pregnancy: Not established
Irritation: Minimal
Daytime use: ✓ Fine
How well established: Early research
Concentration studied: Not disclosed
Length of the studies: 10–12 weeks

Not a measurement — reported irritation grouped into five steps. It varies between people.

“Concentration studied” and “Length of the studies” are taken straight from the research on this page. They are not a recommended dose, and the figure for each finding is written out in the text.

This is not how large the effect is but how well confirmed it is. It shows the highest grade among the findings on this page.

Korean classification Being checkedThe regulatory class has not yet been confirmed against a primary document. It will be filled in once it is.

Astaxanthin is a carotenoid made by microalgae, and what turns salmon and shrimp red. It is known as a strong antioxidant.

One thing to settle first: both trials below used swallowed capsules. It goes into topicals too, but the evidence this page verified is not about applying it. It sits in this layer for the same reason collagen does — it is sold in the skincare aisle on a skin claim.

There are two randomised placebo-controlled trials. That is not a small number in this layer. But each carries a reason it cannot be read at face value, and we set those out below.

And in the 2014 trial, something improved and something did not, in the same people. We record both.

Contents

The UV redness threshold rose — but there are 23 people, and the sponsor wrote the paper
Elasticity and water loss improved — but it was given mixed with collagen
In that same trial, UV-induced DNA damage did not differ

What is established

The same ingredient at a different strength, in a different formula, is a different product. These are the conditions the studies used.

Early researchConcentration studied — Not established

The UV redness threshold rose — but there are 23 people, and the sponsor wrote the paper

A 2018 Japanese trial. 23 healthy Japanese participants were randomised to a 4 mg astaxanthin capsule or placebo for 10 weeks, double-blind.

Measured at week 9:

Minimal erythema dose (MED) — how much UV it takes to redden the skin. It rose on astaxanthin relative to placebo.
Moisture loss in the irradiated area was smaller than on placebo.
On unirradiated skin, the participants' own scores for 'rough skin' and 'texture' improved.

Now what has to be subtracted.

First, 23 people. Split in two, that is about ten per arm. At that size chance has a lot of room to produce a result.

Second, all three authors work for FUJIFILM, and FUJIFILM sponsored and funded the study. The paper says so. We mark that on the badge as 'industry funding'. Industry money does not make a result wrong. It does mean the same result carries different weight than it would from an independent group that reproduced it.

Third, self-rated and instrument-measured items are mixed together. MED and water loss were measured by instruments; 'rough skin improved' is what the participants felt.

So it sits at 'early evidence'. The design is a proper double-blind placebo-controlled trial; the size and the funding do not allow more than that.

Randomised controlled trial in people · 23 participants · 10 weeks · Compared with vehicle (same formula minus the active) · Funding manufacturer-funded · Endpoint instrument measurement PMID 29941810

Early researchConcentration studied — Not established

Elasticity and water loss improved — but it was given mixed with collagen

A 2014 trial at Seoul National University. 44 people with moderate photoageing took 2 mg/day astaxanthin plus 3 g/day collagen hydrolysate, or a placebo identical in look and taste, for 12 weeks.

Results:

Facial skin elasticity improved significantly over placebo
so did transepidermal water loss (TEWL)
in tissue, type I procollagen mRNA rose and MMP-1 and MMP-12 mRNA fell

Here is the fact that matters most: astaxanthin was not measured on its own. A combination was compared against placebo. So what this trial shows is not 'astaxanthin raises elasticity' but 'taking astaxanthin and collagen together beat placebo'.

How much each contributed cannot be recovered from this design. We wrote the same thing on the ectoine page. A trial that mixes two ingredients and beats placebo is not evidence about either ingredient.

And as the collagen page shows, the evidence for swallowed collagen itself is not thick on this site either. Two thin things mixed together beating placebo may mean one of them did the work, or that it takes both.

Randomised controlled trial in people · 44 participants · 12 weeks · Compared with vehicle (same formula minus the active) · Funding not declared · Endpoint instrument measurement PMID 24955642

Not establishedConcentration studied — Not established

In that same trial, UV-induced DNA damage did not differ

Not a new trial — another endpoint of the 2014 study just above.

The investigators irradiated buttock skin with UV and compared UV-induced DNA damage there before and after.

There was no significant difference between the groups.

Why we give this its own entry.

What leads the pitch for astaxanthin is 'powerful antioxidant'. And the job most often named for an antioxidant in skin is reducing the damage UV leaves in cells.

The same trial reported that elasticity improved and that this damage did not.

Both came out of the same 44 people. We do not carry the first across and leave the second behind.

This is why 'what was measured' matters as much as the grade. What this ingredient improved was elasticity on an instrument. What did not show in tissue was DNA damage.

Randomised controlled trial in people · 44 participants · 12 weeks · Compared with vehicle (same formula minus the active) · Funding not declared · Endpoint biopsy findings PMID 24955642

How to use it

The doses were 4 mg a day (2018) and 2 mg a day plus 3 g collagen (2014).
The durations were 10 and 12 weeks. There is no basis for judging it on less.
It does not replace sun protection. What the 2018 trial showed is that the threshold for going red moved a little, not that you can use less sunscreen. Compare it with the 'strong evidence' sunscreen carries on this site.
Evidence for applied products is not on this page. We did not verify that astaxanthin in a cosmetic produces the same results.

Cautions

It is swallowed. If you take other medicines, or are pregnant or breastfeeding, check in a consultation.
Both trials reported mild adverse events, but they had 44 and 23 people. That is not a size that catches rare things.
Yellow or red tinting of the skin is reported with high carotenoid intake. These trials did not report on it separately.
We could not find data on use in pregnancy.

With a new ingredient, apply a small amount somewhere inconspicuous, such as the inner arm, for two days first. Stop if it reddens or stings.

Related skin concerns

Wrinkles Elasticity Dryness

What this article relies on

PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16