Astaxanthin, What Is It?
Astaxanthin is a pigment; a xanthophylls carotenoid belonging to a class called terpenes. It is bright in appearance and lipid-soluble. Some of the places it can be found include crayfish, salmon, trout, yeast, micro algae, krill, shrimp, and the feathers of a few types of birds. It is notable for 
providing the red color of salmon and shellfish that has been cooked. It, unlike many carotenoids, is not converted in the human body to Vitamin A.
While the pigment is found abundant in many sources, there is a market for producing synthetic Astaxanthin.
What Medical Problems Is It Used For?
Its main use is not necessarily medical. For human use, it is approved by the Food and Drug Administration to be a food additive or a food coloring agent. It is also approved for a variety of animal uses, including being used as food supplement.
It is used by most people as a food supplement because it is potentially a very effective anti-oxidant – the most effective anti-oxidant of the carotenoid type. Anti-oxidants treat arthritis, tendon, joint and muscle pain, and for sports or repetitive-related injuries such as tennis elbow. This means that it can be beneficial to athletes. It can also potentially be useful in treating various ailments such as immune, cardiovascular, and neurodegenerative diseases. More recent research suggests that it may be useful in treating various cancers, and that it protects the body from damage caused by oxidation.
Some take as a supplement purely to help with issues such a skin care, and to help improve and maintain eyesight for those with cataracts, glaucoma and other eye issues. Other uses include boosting the immune system, preventing Alzheimer’s and Parkinson’s Disease, increased resistance to colds, diabetes prevention, and enhancing reproductive health. It absorbs UVB very well, helping protect against radiation.
Medical Studies That Back Up Its Claims
In terms of cancer prevention or treatment, there have been multiple studies on rats. So far it has shown to improve resistance to and protect from bladder cancer, as well as doing better in terms of inhibiting cancer 
than the previously tested beta-carotene. In mice, it has reduced inflammation with certain infections.
Astaxanthin has also been shown to improve immune function. It boosts antibody production, as well as and T-cell and T-helper-cell activity. (link to studies)
Active Ingredients, What Do They Do?
Astaxanthin is in fact the active ingredient in the compound. It is the active element that protects algae from the effects of sunlight in nature, similar to what it can do for humans when it comes to the sun and to radiation. The compound is stronger than beta-carotene and Vitamin E.
Side Effects
Thus far there has been no real report of side effects or adverse reactions to the compound. It is probably because it is naturally found in so many living beings. So far, the compound appears to be non-toxic. However, as it has not been thoroughly tested or regulated by every agency or by the Food and Drug Administration, there is no way to guarantee its ingredients when included in supplements, or its safety. Consulting with a physician is recommended before adding supplements to your diet.
It is also recommended forthose who are pregnant or nursing to avoid taking the compound, as it has not been sufficiently tested to determine if there would be adverse effects on the mother or the unborn child. Withhold from using the compound until you have passed the breast-feeding stages, as well.
Is It Safe?
The recommended dose is between four to eight milligrams per day if taken for preventative reasons, but the dose is increased to twelve to sixteen milligrams per day if used to treat inflammation or pain. However, despite the limits of the recommended doses, there is absolutely no reported toxicity level for the compound. To reach the recommended dose from diet alone is nearly impossible, and so if someone is interested in taking the compound as a supplement, they should probably do so by means of ingesting the compound rather than from relying exclusively on food as a source.
While the US Food and Drug Administration has not approved Astaxanthin as a supplement for humans, it is approved as a supplement for fish. More promisingly, the European Union recognizes Astaxanthin as a supplement to the human diet.
Natural and safe, Astaxanthin may be a beneficial supplement added to a healthy life style. With recognition by certain parties – as well as medical studies that show many of its positive effects – the use of Astaxanthin as a supplement or within supplements has been steadily increasing. Trials and studies are still being done on the pigment to verify its benefits as a medical treatment.
