Astaxanthin: History and Discovery
Astaxanthin is the deep red-orange pigment that colours salmon, trout, shrimp, lobster, krill, and contributes to the colour of flamingo feathers. People had eaten it for as long as they had eaten seafood, but nobody knew it was a single, definable molecule until the twentieth century. Its story is mostly a scientific one: a famous German chemist pulling pigments out of lobster shells in the 1930s, a careful piece of synthetic chemistry in the 1970s that finally confirmed its exact structure, and then a slow shift — first as a colourant for farmed fish, later as a human supplement — from a curiosity of crustacean biology to a heavily researched antioxidant. This page traces what the record supports: who named it and when, where the name comes from, how its chemistry was settled, how it came to be grown from microalgae, and how it came to be sold as a supplement. Where a date or attribution is firm we say so; where the popular telling blurs two separate steps, we keep them apart.
Table of Contents
- A Colour Without a Name
- Richard Kuhn and the Lobster Pigments (1933–1938)
- Where the Name Comes From
- Settling the Structure: Laboratory Synthesis (1967–1980s)
- Finding the Source: Haematococcus pluvialis
- From Fish Feed to the Pink Salmon You Buy
- Becoming a Human Supplement (1995 Onward)
- A Quiet Molecule Becomes Heavily Researched
- Key Research Papers
- Connections
- Featured Videos
A Colour Without a Name
For most of human history, astaxanthin was experienced as a colour rather than known as a chemical. The pink-to-scarlet flesh of wild salmon, the orange of cooked shrimp and lobster, the rich red of salmon roe, and part of the pink of flamingos come from the same pigment (in many flamingo species canthaxanthin is the more abundant pigment; Nishida 2023). Coastal peoples ate it constantly without any idea that a single compound lay behind all these reds. One everyday observation in particular hinted that something interesting was going on: a live or raw lobster is a dull blue-green, yet it turns bright red the instant it is cooked. That colour change happens because astaxanthin is bound to shell proteins called crustacyanins, which shift its colour to blue, and heat releases it from the protein complex (Nishida 2023).
The scientific path to astaxanthin runs through the study of carotenoids, the large family of yellow, orange, and red pigments that includes beta-carotene (from carrots) and lycopene (from tomatoes). In the first decades of the twentieth century, carotenoid chemistry was one of the most active frontiers in organic chemistry, and the pigments of animals — especially the vivid colours of crustaceans and fish eggs — were an obvious target. It was within this wave of research, not as an isolated discovery, that astaxanthin was first pinned down.
Richard Kuhn and the Lobster Pigments (1933–1938)
The molecule we now call astaxanthin was isolated and named by the chemist Richard Kuhn (born in Vienna in 1900, died in Heidelberg in 1967) and his collaborators, working in Heidelberg, Germany. The work came in two documented steps that the popular version often merges into one.
The first step, in 1933, was carried out by Kuhn together with Edgar Lederer. Working with the European lobster — then classified as Astacus gammarus (the same animal is now usually called Homarus gammarus) — they isolated two carotenoids from its shell and eggs and named them "astacin" (now called astacene) and "ovoester" (Kuhn and Lederer 1933; Nishida 2023). These were the raw materials of the discovery, not yet the finished molecule under its modern name.
The second step, in 1938, was the decisive one. In that year Kuhn, now working with Nils Andreas Sörensen, identified "ovoester" as a xanthophyll carotenoid and renamed it astaxanthin, the name it still carries (Nishida 2023). Their paper, "Über Astaxanthin und Ovoverdin," appeared in the German chemistry journal Berichte der deutschen chemischen Gesellschaft in 1938. ("Ovoverdin," the other subject of the paper, is the green carotenoid–protein pigment of lobster eggs, isolated in 1937 by Stern and Salomon.) This 1938 paper is the one cited for the name astaxanthin.
It is worth being clear about Kuhn's stature, because it explains why this attribution is so secure. Kuhn was one of the leading carotenoid chemists of his era and was awarded the Nobel Prize in Chemistry for 1938 "for his work on carotenoids and vitamins." According to the Nobel Foundation, Kuhn "was caused by the authorities of his country to decline the award, but he later received the diploma and the medal." The discovery of astaxanthin belongs to exactly this body of pigment-and-vitamin chemistry for which he is remembered.
Where the Name Comes From
The name astaxanthin is built from two parts, and tracing them is a small lesson in how chemical names are made. The ending "-xanthin" comes from the Greek xanthos, meaning "yellow," and marks the molecule as a xanthophyll — the oxygen-containing branch of the carotenoid family, as opposed to the pure-hydrocarbon "carotenes" like beta-carotene.
The first part, "asta-," comes from Astacus, the scientific genus name of the lobster from which Kuhn and his colleagues first drew the pigment. The genus name Astacus itself derives from the ancient Greek astakos, meaning "lobster" or "crayfish" which is why some sources describe astaxanthin's name as coming directly from the Greek for "lobster" plus "yellow." Both tellings point to the same origin; the molecule is, quite literally, "the yellow (xanthophyll) pigment of the lobster." The related early name "astacin," from the same 1930s work, comes from the same root (Nishida 2023).
The name is a fitting one. Although astaxanthin is now produced commercially mainly by chemical synthesis and from microalgae and yeast rather than from shellfish, the crustacean it was first found in is preserved permanently in its name — a common pattern in chemistry, where a molecule is christened after the organism that first gave it up.
Settling the Structure: Laboratory Synthesis (1967–1980s)
Naming a pigment and isolating it is not the same as knowing its exact molecular structure with certainty. For carotenoids, strong proof is synthesis: building the molecule in the laboratory and showing that the synthetic product matches the natural one. For astaxanthin this happened in steps. In 1967 Surmatis and colleagues synthesized it in its dimethyl ester form, and in the same year Leftwick and Weedon synthesized the free form from canthaxanthin (Nishida 2023).
In 1975 Robin D. G. Cooper, John B. Davis, Allan P. Leftwick, Colin Price and Basil C. L. Weedon published the synthesis of astaxanthin and several related pigments as part of Weedon's long series on carotenoid chemistry, in the Journal of the Chemical Society, Perkin Transactions 1 (Cooper 1975). In the same year Liaaen-Jensen and colleagues obtained optically active astaxanthin from the green alga Haematococcus (Nishida 2023). The molecule is, in modern terms, 3,3'-dihydroxy-β,β-carotene-4,4'-dione — a beta-carotene skeleton carrying an extra hydroxyl and keto group on each end ring.
In the early 1980s an industrial research group achieved a total synthesis that produced all three optical isomers of astaxanthin (Nishida 2023), and from 1984 a synthetic astaxanthin formulation was sold to colour the flesh of farmed salmon and trout; it remains the most widely used astaxanthin product in fish farming (Nishida 2023). Synthetic astaxanthin is a mixture of the 3S,3'S, meso and 3R,3'R isomers (Ambati 2014). As the next sections explain, the synthetic product became the main colourant of the farmed-fish industry, while natural sources were developed for human supplements.
Finding the Source: Haematococcus pluvialis
Astaxanthin's natural history is one of its most elegant features: animals do not make it themselves. The pigment in a salmon's flesh, a flamingo's feathers, or a lobster's shell is borrowed, passed up the food chain from the organisms at the bottom that actually manufacture it. The most important of those producers is a humble freshwater green microalga, Haematococcus pluvialis.
This alga has a long pedigree in biology quite apart from astaxanthin. Descriptions of Haematococcus, its biology and its life cycle go back to the German botanist Julius von Flotow in 1844 and the American botanist Tracy Elliot Hazen in 1899; early botanists described a "blood red pigment" that was later identified as astaxanthin (Nishida 2023). Under stress such as strong light, nutrient shortage, high salinity or heat, the green swimming cells turn into red resting cysts that accumulate astaxanthin; reviews report contents of up to about 3–5% of dry weight (Ambati 2014; Shah 2016).
That biological response is the foundation of the natural-astaxanthin industry. Producers grow Haematococcus in open ponds or closed photobioreactors, usually in two stages — a green growth stage and a red stage in which the cells are stressed to drive astaxanthin production — then harvest the cysts and extract the pigment (Shah 2016). A separate natural source — the red yeast once called Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) — is also used (Ambati 2014); according to a 2023 review, yeast- and bacteria-derived astaxanthin still hold a small market share compared with Haematococcus in human products (Nishida 2023).
From Fish Feed to the Pink Salmon You Buy
The first large commercial use of astaxanthin had nothing to do with human health — it was about the colour of fish. Wild salmon and trout are pink because their diet of krill and other small crustaceans contains astaxanthin. A 2014 review reports 26–38 mg of astaxanthin per kg of flesh in wild sockeye salmon, against 6–8 mg per kg in farmed Atlantic salmon (Ambati 2014). Farmed fish get their astaxanthin from pigment added to their feed. In the 1980s krill and krill extracts were used as a feed colouring in aquaculture, and Antarctic krill was used to colour sea bream in Japan (Nishida 2023).
From 1984 synthetic astaxanthin became the most widely used astaxanthin product for colouring farmed salmon and trout (Nishida 2023). The industry uses commercial colour-scoring fans and cards to grade flesh colour against a numbered scale, so the pink of farmed salmon is, quite literally, a feed-formulation decision. The source leaves a chemical fingerprint: the mix of stereoisomers in the flesh can be used to tell wild salmon from farmed salmon fed synthetic astaxanthin (Turujman 1997).
In the United States, the Food and Drug Administration lists astaxanthin as a colour additive for the feed of salmonid fish "to enhance the pink to orange-red color of the flesh": synthetic astaxanthin (21 CFR 73.35, listed in 1995), and Haematococcus algae meal (21 CFR 73.185) and Phaffia yeast (21 CFR 73.355), both listed in 2000. Each is capped at 80 mg of astaxanthin per kg of finished feed. These listings are about colouring farmed fish, not about adding the pigment to human food — a distinction that matters for the separate story of astaxanthin as a supplement.
Becoming a Human Supplement (1995 Onward)
Taking astaxanthin itself as a supplement is comparatively recent, and it tracks the rise of microalgal cultivation. According to a 2023 review, the first astaxanthin supplement for human use was launched in Europe in 1995, and astaxanthin reached the North American supplement market in the late 1990s, slightly later than in Europe and East Asia (Nishida 2023).
In the United States, the FDA does not approve dietary supplements before they are marketed; under the Dietary Supplement Health and Education Act it has no authority to do so. The FDA has not approved astaxanthin as a supplement: its FDA listings remain the fish-feed colour additives described above. In the European Union, the European Food Safety Authority concluded in 2020 that 8 mg/day of astaxanthin from food supplements, on top of the usual diet, is safe for adults, using an acceptable daily intake of 0.2 mg per kg of body weight (EFSA 2020).
This history left a divide between the two products. Synthetic astaxanthin, a mixture of three stereoisomers, is the main fish-feed colourant; natural astaxanthin from Haematococcus occurs mainly as fatty-acid esters of the 3S,3'S form (Nishida 2023), and many of the human trials state an H. pluvialis source. A 2019 safety review argues that synthetic astaxanthin is chemically different from natural astaxanthin and that few safety studies in humans or animals have used it (Brendler 2019).
A Quiet Molecule Becomes Heavily Researched
For decades after Kuhn named it, astaxanthin was studied mostly in fisheries research, and until the 1990s much of that work was done in Japan (Nishida 2023). Interest in human health followed laboratory findings on its antioxidant chemistry: in a 1991 study it quenched singlet oxygen far faster than vitamin E in a test-tube assay (Nishida 2023). A 2007 solvent assay produced the widely repeated "6,000 times vitamin C" figure; in that assay's rate constants, astaxanthin was 5.4 and vitamin C 0.00089 (in 109 per molar per second; Nishida 2023). These are reaction speeds in a test tube, not effects in people. In membrane and cell studies, astaxanthin did not show the pro-oxidant effect that beta-carotene did (McNulty 2007), but no long-term outcome trial comparable to the ATBC and CARET beta-carotene trials of the 1990s has tested astaxanthin.
The growth of the scientific literature captures the shift plainly. A recent overview, the 2023 review "Astaxanthin: Past, Present, and Future," reports that PubMed-indexed papers on astaxanthin rose from 29 in 2001 to 414 in 2022, which the review describes as a fourteen-fold increase (Nishida 2023); a PubMed search in October 2026 returns about 4,700 papers in total. A pigment first pulled from lobster shells before the Second World War is now one of the more intensively studied antioxidants in nutrition science.
That is where the history hands off to the present. The mechanisms, the clinical evidence for eye, skin, cardiovascular, exercise, brain and other outcomes, the doses used in trials, and the safety findings are covered in the companion Astaxanthin Benefits articles and on the main Astaxanthin page; this history is concerned only with how the molecule came to be known, named, made, and eventually taken on purpose. In short: tradition supplied the colour, twentieth-century chemistry supplied the molecule and its structure, and microalgal biotechnology supplied the means to study and use it.
Key Research Papers
The list below gives the primary and review literature on astaxanthin's discovery, chemistry and history. The 1933 isolation paper, the 1938 naming paper and the 1975 synthesis paper are the historical primary sources.
- Kuhn R, Lederer E. Über die Farbstoffe des Hummers (Astacus gammarus L.) und ihre Stammsubstanz, das Astacin. Berichte der deutschen chemischen Gesellschaft (A and B Series). 1933;66(4):488–495. — doi:10.1002/cber.19330660410
- Kuhn R, Sörensen NA. Über Astaxanthin und Ovoverdin. Berichte der deutschen chemischen Gesellschaft (A and B Series). 1938;71(9):1879–1888. — doi:10.1002/cber.19380710918
- Cooper RDG, Davis JB, Leftwick AP, Price C, Weedon BCL. Carotenoids and related compounds. Part XXXII. Synthesis of astaxanthin, phoenicoxanthin, hydroxyechinenone, and the corresponding diosphenols. Journal of the Chemical Society, Perkin Transactions 1. 1975:2195–2204. — doi:10.1039/p19750002195
- Nishida Y, Berg PC, Shakersain B, Hecht K, Takikawa A, Tao R, Kakuta Y, Uragami C, Hashimoto H, Misawa N, Maoka T. Astaxanthin: Past, Present, and Future. Marine Drugs. 2023;21(10):514. — doi:10.3390/md21100514 · PubMed PMID: 37888449
- Shah MMR, Liang Y, Cheng JJ, Daroch M. Astaxanthin-producing green microalga Haematococcus pluvialis: from single cell to high value commercial products. Frontiers in Plant Science. 2016;7:531. — doi:10.3389/fpls.2016.00531 · PubMed PMID: 27200009
- Ambati RR, Phang SM, Ravi S, Aswathanarayana RG. Astaxanthin: sources, extraction, stability, biological activities and its commercial applications — a review. Marine Drugs. 2014;12(1):128–152. — doi:10.3390/md12010128 · PubMed PMID: 24402174
- Turujman SA, Wamer WG, Wei RR, et al. (1997). Rapid liquid chromatographic method to distinguish wild salmon from aquacultured salmon fed synthetic astaxanthin. Journal of AOAC International — PubMed PMID: 9170658
- McNulty HP, Byun J, Lockwood SF, et al. (2007). Differential effects of carotenoids on lipid peroxidation due to membrane interactions: X-ray diffraction analysis. Biochimica et Biophysica Acta — PubMed PMID: 17070769
- Brendler T, Williamson EM (2019). Astaxanthin: How much is too much? A safety review. Phytotherapy Research — PubMed PMID: 31788888
- EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, Castenmiller J, et al. (2020). Safety of astaxanthin for its use as a novel food in food supplements. EFSA Journal — PubMed PMID: 32874213
PubMed Topic Searches
- Astaxanthin discovery, history and naming — PubMed: astaxanthin history and discovery
- Haematococcus pluvialis astaxanthin production and commercialisation — PubMed PMID: 42704534