There are literally hundreds of products available to help improve male sexual function, including patent medicines and natural products. Many of the natural products have been used in traditional medicine for centuries, and some are known to have been used for thousands of years.
Most of these natural products are combinations of multiple ingredients. I formulated one of those in the 1990s; it’s trade-named ‘Male®’ and is available in natural health food stores and the Tahoma Clinic Dispensary. Although it doesn’t work for 100% of those who try it, the majority of men tell me it helps anywhere from a little to a lot.
Since then, there’s been enough additional research in this area to make it reasonable to put together another formula, one which addresses male sexual function in different as well as overlapping ways.
Let’s briefly review the mineral and botanical components of this new all-natural formula.
Researcher uncovers ‘oyster secret’ to male sexual function
For generations, folk traditions have related that eating oysters is helpful for male sexual function. Finally, in the 1960s, Dr. Ananda Prasad’s famous ‘Iranian dwarf’ studies demonstrated clearly that zinc, a mineral that oysters are particularly high in, is essential not only to testosterone synthesis, but also to the production of growth hormone (HGH). Many of the men in Dr. Prasad’s early studies were in their early 20s, significantly shorter than expected for their age, and with virtually no ‘secondary sexual development’. With zinc supplementation, they grew taller and developed sexually. Dr. Prasad’s work proved conclusively that zinc is necessary for testosterone synthesis, and – by extension – that consuming high zinc foods such as oysters to help male sexual function wasn’t just a ‘folk legend’ after all.
As zinc also helps prostate function, it’s found in nearly every product for male sexual function, and it couldn’t be left out of this one!
Sexual function and longevity linked to vitamin A
Vitamin A, on the other hand, is rarely found in male sexual function products. But it should be, because together with zinc, vitamin A stimulates growth hormone (HGH) in both men and women.
In male rats, vitamin A is essential for the function of testosterone-producing testicular Leydig cells and sperm-promoting Sertoli cells.1 Although this has not yet been proven in human males, the likelihood is overwhelming that this is the case since human male testicular cells have several types of vitamin A receptors.
Higher levels of vitamin A are also one of several nutrients found to correlate with longevity. As we grow older, our bodies synthesise less and less vitamin A from beta-carotene.
Missing manganese linked to sexual dysfunction
I haven’t seen manganese in any male sexual function products, but there’s definitely good reason for it to be there! There’s plenty of research on this, both old (1930s) and new (2006-2008). First the ‘old.’
Dr. E. V. McCollum of Johns Hopkins University was a very well-known nutritional researcher during the first half of the 20th century. In 1931, he and Dr. Elsa R. Orent published the classic research paper Effects of Deprivation of Manganese in the Rat. They wrote:
“Male rats grow normally on [a manganese-deprived diet] and show no abnormalities until about 90 to 100 days on the diet. They then become sterile owing to immotility [lack of motion] of their sperm cells. After about 150 days on the diet many males show no sperm cells… During the period of degeneration of the germinal epithelium [the sperm cell-generating cells] the testes decrease in size. They may show sperm cells even after they have decreased to about half the normal size… 72 male rats were raised on [the manganese-free diet], all of which showed testicular degeneration. After 9 months on the diet the testes were about the size of those of a 6 weeks old rat. They were soft, flabby, cyanotic [bluish], translucent in appearance, edematous, and had undergone tubular destruction. The atrophy rapidly progresses. The epididymis finally degenerates completely until only vestiges remain. Sterility was demonstrated in these rats both by testicular smears and by mating tests. By 90 to 100 days they became indifferent to females which were placed in the cage, whereas normal males always examine them with interest.”
In the same research, McCollum and Orent observed that manganese is also essential to many aspects of female reproductive function. In addition to observing ‘stillbirths’ born to manganese-free mother rats, they wrote: “These females, deprived of manganese, failed in 58 of 59 cases to suckle their young. They appeared indifferent to them and did not give them the care or opportunity to suck which is characteristic of female rats on the same dietary formula with small amounts of manganese added.”
In 1931, no one knew why manganese-free diets would produce these effects. However, McCollum and Orent shrewdly guessed at the reason, writing: “The testicular atrophy and the failure of females to suckle young suggest failure of some hormone production in the hypophysis.” (‘Hypophysis’ is another word for ‘pituitary’.)
Despite this landmark research paper, for the rest of the 20th century and into the 21st, no one ever put manganese into a supplement for improvement of human male (or female) hormone function and/or fertility. The defence might be that ‘people aren’t rats’, and in most cases, that’s correct (sorry about that). But even so, Nature and Creation are very, very conservative, and are known to use basic elements for the same purposes over and over in many living creatures.
Finally, in 2006 through to 2008, researchers published at least one part of the fulfilment of McCollum and Orents’ prediction.2 Working with both male and female rats, they found that in the hypothalamic part of the brain (the part above the pituitary gland) manganese stimulates ‘luteinising hormone releasing hormone’ (LHRH), which in turn stimulates the ‘luteinising hormone’ (LH) that stimulates testosterone production in males, and progesterone in females.
Spur testosterone production with vital vitamin K
You likely know about the connection between vitamin K and blood clotting, and you may also know that vitamin K is necessary for bone health. However, recent research has revealed that vitamin K (specifically the type of vitamin K termed menaquinone or ‘MK4’) directly stimulates testosterone, too.2 Instead of the indirect action that manganese has, vitamin K appears to work directly on the testicles rather than on other hormones, which in their turn stimulate testosterone production.
Here’s an excerpt from the research abstract: ‘Testosterone levels in the plasma and testes of MK-4-fed rats were significantly increased compared to those of control rats, with no obvious differences in plasma luteinising hormone levels.’3
New research reveals magnesium increases testosterone
Very recent research has found that magnesium increases testosterone in men who exercise as well as those who do not. One group of researchers wrote: “… In a cohort of 399 older men, magnesium levels are strongly and independently associated with the anabolic hormones testosterone and IGF-1.”4 (As many know, ‘IGF1’ is a ‘surrogate marker’ which correlates with levels of growth hormone.)
Another research group compared the effects of magnesium supplementation in exercising and sedentary men. They wrote: “Magnesium increases free and total testosterone… the increases are higher in those who exercise than in sedentary individuals.”5
A caution: the amount of magnesium taken by these research volunteers was 10mg per kilogram. As the average man (medical school version) weighs 70kg, that’s enough magnesium to give a few of us loose bowels or even diarrhoea, and a few more an overly rapid ‘intestinal transit time’, which means that you may not be absorbing all of the nutrients you need from your food. For these reasons, it’s best to measure your own intestinal transit time before taking more magnesium than 300mg to 400mg daily.
Boron boosts free testosterone
Boron is another nutrient that hasn’t yet made it into most formulas for male sexual function. That’s because the research you may have read about in the January 2013 issue of Nutrition & Healing received very little coverage.6 Boron doesn’t stimulate testosterone either directly or indirectly like the nutrients noted above. Instead, it re-distributes the testosterone, making more of it available as ‘free’ testosterone.
As most readers know, the free form of any hormone is the active form and the only form which can activate hormone receptors. According to the researchers: “…Eight healthy male volunteers… were requested to consume a capsule of 10mg boron every day… After one week (in samples taken at 8.00 A.M only) the mean plasma free testosterone increased and the mean plasma oestradiol decreased significantly…”
In other words, the overall testosterone level didn’t increase with boron supplementation, but, the amount of active testosterone increased significantly. This meant that more receptors could be activated, giving an increased testosterone effect.
Ancient ‘medicinal’ fruit boosts LH and testosterone levels
The fruit of Tribulus terrestris has been used traditionally for centuries, even thousands of years, in Ayurvedic medicine to relieve problems of the male and female reproductive and urinary systems. It’s also considered an aphrodisiac.
The human research which put tribulus on the map used Tribestan®, a specific Bulgarian extract of tribulus leaf standardised to contain not less than 45% saponins. Research concerning tribulus is conflicting; however, as pointed out by my colleague and master herbalist Kerry Bone, the quality of tribulus supplements varies widely, with some having a very low percentage of active ingredients.
In Bulgarian research, 750mg of tribulus daily for just five days increased LH and testosterone in healthy men.7 The product used (Tribestan®), which contained 45% saponins. In three clinical trials, also conducted in Bulgaria (with 212 male participants), this same product was found to significantly improve male sexual function.8,9,10
Kerry Bone has reported previously that in some men taking 1,500mg of tribulus daily, there were significant increases in LH and testosterone, and decreases in oestradiol.
Other research done outside of Bulgaria has not confirmed these positive results. However, I’m including it in my formula for several reasons. First, it’s another traditional folk medicine used successfully for hundreds of years to support male sexual function. Second, several men have told me how well the higher concentrations did for them. Lastly, in this formula, it’s a 40% to 50% concentration of saponins (similar to the positive Bulgarian research).
‘Smell of the stallion’ herb earns its name
Ashwagandha (technically Withania somnifera) is another traditional medicine – again from the Ayurvedic tradition. The herb has been used for millennia in India and elsewhere for improving male sexual function. (Although I don’t speak the language, I’m told by those who do that the name ‘ashwagandha’ means ‘smell of the stallion,’ in itself somewhat suggestive of at least one function it may have.)
One research group recently wrote: ‘…treatment [with ashwagandha] also significantly increased serum testosterone and LH, and reduced the levels of FSH and PRL [prolactin]…’11
Another team reported on the effect of ashwagandha in three groups of men, all with normal sperm counts.12 One group was fertile, a second group infertile and under stress, and members of the third group were all cigarette smokers. These researchers reported that after treatment with Withania somnifera, testosterone levels improved in the fertile men by 13%, the infertile men who were under stress by 22%, and in the cigarette smokers by 10%. (Ashwagandha has also been reported by these two research groups to significantly decrease stress-elevated levels of cortisol, an added bonus.)
Help erectile dysfunction with Panax ginseng
Panax ginseng has been used for thousands of years in Chinese medicine as an anti-ageing remedy and sexual stimulant. In my opinion, anything used repeatedly for thousands of years probably does have the effects attributed to it, but of course that’s not outright proof.
In 2007, Brazilian researchers reported a double-blind, placebo-controlled study of Panax ginseng (1,000mg three times daily) involving 60 men with ‘mild to moderate’ erectile dysfunction.13 They concluded that in the men who took ginseng the ‘International Index of Erectile Function’ (yes, there really is such a thing) improved significantly (p<0.0001). There was no improvement in the men taking a placebo.
Despite the significant improvements in ED in the men taking ginseng, there was no significant improvement in testosterone levels.
Icariin works like Viagra®
Epimedium is another botanical traditionally used for male sexual function that has been recently validated by modern research techniques. Epimedium is the official name for ‘horny goat weed’, which tradition says got its name after a goatherd observed male goats becoming quite ‘frisky’ after eating it.
While this part of the horny goat weed story is relatively well known, what’s not yet as well known is that one of its major components, Icariin, works in the same way as the patent medicine Viagra®.
Both improve erectile function by inhibiting an enzyme known as phospodiesterase-5 (PDE-5). The evidence for this is strong enough that the United States Patent Office voided the part of the Viagra® patent that claimed it to be unique in this mechanism of action.14
However, icariin’s PDE-5 inhibitory action is considerably weaker than that of Viagra®. According to a 2006 research report, icariin’s ‘EC50’ (a commonly used measure of potency) is approximately 4.62 μM, while Viagra’s® EC50 is .42 μM. In English, this measurement says that 10 times more icariin is needed to have approximately the same effect as Viagra®.
Fortunately for interested men, this ten to one difference in strength is not insurmountable As many men know, Viagra® is sold in 25mg, 50mg, and 100mg per tablet sizes. If the ‘10 to one’ strength ratio is meaningful, then 250mg to 1,000mg of icariin itself might be in the right range to be useful for male sexual function.
Because of price considerations, there are 140mg of icariin itself in this product, not enough for as ‘powerful’ an effect as Viagra® all by itself, but definitely enough to be noticeable when needed, especially in combination with the other ingredients.
Men using the combination formula may notice some improvement in overall function ‘early on’ from the quicker-acting nutrients such as boron and icariin, but it will take up to a month for some of the nutrients – such as magnesium, manganese, vitamin K, and ginseng – to have their full effect.
So I bet you are wondering what this powerful mix of zinc (‘offset’ by copper, very necessary for longterm use), manganese, vitamin K, magnesium, boron, vitamin A, Tribulus terrestris, ashwagandha, Panax ginseng and icariin is called. It’s been named Vicariin® and yes, I developed the formulation – but not the name! It’s available (or will be very soon) at many natural health food stores and right now at the Tahoma Clinic Dispensary. Enjoy!Wishing you the best of health,
Dr. Jonathan V. Wright
Nutrition & Healing
Volume 7, Issue 4 – April 2013
Full references and citations for this article are available in the downloadable PDF version of the monthly Nutrition and Healing issue in which this article appears.