Astaxanthin Health & Wellness Testosterone Boost

Astaxanthin is a potent antioxidant; affects hormonal balance

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Astaxanthin is a reddish pigment that belongs to a group of chemicals called carotenoids. Astaxanthin is found in yeast, salmon, trout, shrimp, crayfish, crustaceans, and some algae (Hematococcus pluvialis). There is an increasing amount of evidence to suggest that astaxanthin surpasses the antioxidant benefits of beta-carotene, zeaxanthin, canthaxanthin, vitamin C and vitamin E.

Astaxanthin Hormonal Effects

There is some preliminary evidence [1] (in support to patent US 6,277,417 B1 [2]) where astaxanthin demonstrated 98% inhibition of 5-alpha reductase at 300 microg/mL in vitro. Combination of astaxanthin and saw palmetto berry lipid extract showed a 20% greater inhibition of 5-alpha reductase than saw palmetto berry lipid extract alone in vitro [1]. This study also showed increased testosterone and decreased dihydrotestosterone levels (due to inhibition of 5-alpha reductase enzyme) [1].

Study in infertile men suggests a positive effect of astaxanthin on sperm parameters and fertility [5]. However, no increase in serum testosterone was noted compared to placebo group [5].

Why do Bodybuilders use 5-alpha Reductase Inhibitors?

5-alpha reductase inhibitors are used medically to treat benign prostatic hyperplasia [3] and hair loss [4] but in bodybuilding world they spark much controversy. When bodybuilders supplement with anabolic steroids or testosterone boosters may also like to add 5-alpha reductase inhibitors. 5-alpha reductase is the enzyme that converts testosterone into the more potent androgen dihydrotestoterone. Dihydrotestosterone has its ups and downs for bodybuilders. While it causes hair loss and some other negative effects, studies show increased protein synthesis, cell signaling, cell proliferation and ATP production, as well as muscle contraction and relaxation in vivo [6] and increased amino acid uptake in vitro [7].

Astaxanthin as an Antioxidant

As mentioned in the intro astaxanthin is a potent antioxidant [8-10,13]. Carotenoids are potent biological antioxidants which absorb excited energy of oxygen onto the carotenoid chain which prevents potential damage to other molecules in the tissue [8]. Astaxanthin is very good at protecting membranous phospholipids and other lipids against peroxidation [9]. A few studies evaluated its antioxidant power and some show many times stronger antioxidant activity than vitamin E [9] and beta-carotene [10].

It should be noted that there is much controversy around the concept of antioxidants due to reported inconsistencies by clinical trials.


Ingestion of fat along with carotenoids is thought to contribute to their better absorption [11]. However, when multiple carotenoids are ingested together absorption of either may be reduced as competition for absorption may occur at the level of intestinal uptake [11]. Karppi et al. [12] reported that intestinal absorption of astaxanthin is adequate.

Side Effects and Toxicity

Because astaxanthi influences hormonal changes one should be aware that it might negatively interact with some hormone-altering medications. Astaxanthin delivered as capsules seems to be well tolerated [12]. It has reported that 6 to 20 mg of astaxanthin per day for 4 to 12 weeks can be safely consumed by healthy adults with no apparent abnormalities [13,14].


  1. Anderson, Mark L. “A preliminary investigation of the enzymatic inhibition of 5α-reductase and growth of prostatic carcinoma cell line LNCap-FGC by natural astaxanthin and saw palmetto lipid extract in vitro.” Journal of herbal pharmacotherapy 5.1 (2005): 17-26.
  2. Anderson, Mark. “Method of inhibiting 5. alpha.-reductase with astaxanthin.” U.S. Patent No. 6,277,417. 21 Aug. 2001.
  3. Roehrborn, Claus G., et al. “Efficacy and safety of a dual inhibitor of 5-alpha-reductase types 1 and 2 (dutasteride) in men with benign prostatic hyperplasia.” Urology 60.3 (2002): 434-441.
  4. Olsen, Elise A., et al. “The importance of dual 5α-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride.” Journal of the American Academy of Dermatology 55.6 (2006): 1014-1023.
  5. Comhaire, F. H., et al. “Combined conventional/antioxidant Astaxanthin treatment for male infertility: a double blind, randomized trial.” Asian journal of andrology 7.3 (2005): 257-262.
  6. Yoshioka, M., et al. “Effects of dihydrotestosterone on skeletal muscle transcriptome in mice measured by serial analysis of gene expression.” Journal of molecular endocrinology 36.2 (2006): 247-259.
  7. Hamdi, Muhammad M., and G. Mutungi. “Dihydrotestosterone stimulates amino acid uptake and the expression of LAT2 in mouse skeletal muscle fibres through an ERK1/2‐dependent mechanism.” The Journal of physiology 589.14 (2011): 3623-3640.
  8. Mortensen, Alan, et al. “Comparative mechanisms and rates of free radical scavenging by carotenoid antioxidants.” FEBS letters 418.1 (1997): 91-97.
  9. Kurashige, Michi, et al. “Inhibition of oxidative injury of biological membranes by astaxanthin.” Physiol. Chem. Phys. Med. NMR 22.1 (1990): 27-38.
  10. Shimidzu, Nobuyoshi, Masafumi Goto, and Wataru Miki. “Carotenoids as singlet oxygen quenchers in marine organisms.” Fisheries Science 62 (1996).
  11. van het Hof, Karin H., et al. “Dietary factors that affect the bioavailability of carotenoids.” The Journal of nutrition 130.3 (2000): 503-506.
  12. Karppi, Jouni, et al. “Effects of astaxanthin supplementation on lipid peroxidation.” International journal for vitamin and nutrition research 77.1 (2007): 3-11.
  13. Spiller, Gene A., and Antonella Dewell. “Safety of an astaxanthin-rich Haematococcus pluvialis algal extract: a randomized clinical trial.” Journal of medicinal food 6.1 (2003): 51-56.
  14. Satoh, Akira, et al. “Preliminary clinical evaluation of toxicity and efficacy of a new astaxanthin-rich Haematococcus pluvialis extract.” Journal of clinical biochemistry and nutrition 44.3 (2009): 280.