Saw Palmetto, Stinging Nettle, and OTC Men’s Supplements

Saw Palmetto is touted as an OTC (over-the-counter) men’s supplement that can counteract DHT, which is said to cause baldness and prostate problems.  It does this by inhibiting the pathway of testosterone to DHT.  However, the alternative pathway is to estradiol!  This is not what most men want!  Many using finasteride (Proscar, Propecia) and dutasteride (Avodart), which are DHT inhibitors, have ended up with hormonal problems, and this may be the reason.  Erectile dysfunction, impotence, low libido and gynecomastia (male breasts) are some of the side effect of these 5-alpha reductase inhibitor drugs. [1,2]

DHT inhibitors are not a good idea because DHT metabolites play an essential role in mental health.  One of these DHT metabolites, 3α-diol (or 5α-androstane, 3α, 17α-diol), has been shown to reduce anxiety, depression, and cognitive decline in older rats.  When the rats are given indomethacin, which blocks the conversion of DHT to 3α-diol, they show decreased cognitive performance and increased anxiety. Testosterone and DHT bind to androgen receptors, while 3α-diol has actions at GABA receptors in the hippocampus in the brain. [6]

Stinging nettle is another OTC supplement that is said to decrease SHBG (sex hormone binding globulin).  But one study showed it caused gynecomastia in a male, and galactorrhoea (breast milk) in a woman who was not lactating.  Both subjects had been drinking nettle tea for about a month before the onset of their symptoms, which decreased once they stopped taking the herb. [3]

Testosterone raising supplements ordered online have resulted in some negative side effects.  One medical journal report on ActivaTe Xtreme™ profiled a 19-year-old male who developed  “fluid retention,” lack of libido and erectile dysfunction.  He was found to have high serum testosterone and raised LH (luteinising hormone). [4]

Aggressive prostate cancer developed in two men within months of their starting daily consumption of an herbal/hormonal dietary supplement.  An analysis of the product showed it contained both testosterone and estradiol.  A warning letter from the FDA to the manufacturer led to the product being removed from the market. [5]

Be wary of taking anything that can alter hormone pathways.  The results may not be what you anticipated!

  1. Barry Wheeler.5-Alpha Reductase Over-Inhibition.  Meridian Valley Lab website.  November 17, 2010.
  3. Mustafa Sahin, Hamiyet Yilmaz, Alptekin Gursoy, Asli Nar Demirel, Neslihan Bascil Tutuncu, Nilgun Demirag Guvener. Gynaecomastia in a man and hyperoestrogenism in a woman due to ingestion of stinging nettle (Urtica dioica). New Zealand Medical Journal,  9 November 2007, Vol 120 No 1265, 65-67.
  4. Tim J. McDonald, Mandy H. Perry, Angus G. Jones, Mollie Donohoe, Maurice B. Salzmann, John O’Connor. A novel case of a raised testosterone and LH in a young man. Clinica Chimica Acta.  Volume 412, Issues 21-22, 9 October 2011, Pages 1999-2001.
  5. Shariat SF, Lamb DJ, Iyengar RG, Roehrborn CG, Slawin KM.Herbal/hormonal dietary supplement possibly associated with prostate cancer progression. Clin Cancer Res. 2008 Jan 15;14(2):607-11.
  6. Cheryl A. Frye, Kassandra L. Edinger, Edwin D. Lephart, and Alicia A. Walf. 3α-Androstanediol, but Not Testosterone, Attenuates Age-Related Decrements in Cognitive, Anxiety, and Depressive Behavior of Male Rats. Frontiers in Aging Neuroscience. 2010; 2: 15.  Published online 2010 April 8.