Issue:
99
Page: 34-45
Herbs and Erectile Dysfunction: A Review of Traditional Use and Modern Clinical Evidence
by Linda Woolven, Ted Snider
HerbalGram.
2013; American Botanical Council
Since ancient times, cultures around
the world have turned to herbs for help with erectile dysfunction (ED). The
astonishing number of plants that have been believed to possess aphrodisiac and
performance-enhancing powers suggests that people in every geographical
location and throughout every era have sought herbal help for fertility and
reproductive power. Ethnobotanist James A. Duke’s database of herbs
lists 239 herbs that reportedly have been used as folkloric aphrodisiacs
and 122 that have been used for impotence (J. Duke, email, July 2, 2013). There
is an ancient and intimate relationship between man and nature in the quest for
enhanced sexual power.
Although some of the folkloric
solutions seem truly outrageous, others have been vindicated by science. While
doing field work in Tobago, the authors of this article came across a popular
beverage tellingly titled “Hard Wine,” which combined the equally aptly named
horny goat weed (Epimedium sagittatum,
Berberidaceae) with eleuthero (Eleutherococcus senticosus, Araliaceae) and a tree bark called bois bandé — all soaked in a red fruit
wine.
The label and the hyped claims lent
the product an air of illegitimacy. But horny goat weed does have a tradition
of increasing virility and fertility. Known in China as yin yang huo, which translates literally as horny goat weed, the
herb has been used for more than a thousand years for sexual conditions,
including those of impotence and fertility.1 In Traditional Chinese
Medicine (TCM), horny goat weed is used to increase sexual energy in both men
and women through its ability to “warm the kidneys.” In TCM, low energy of the
kidney is often involved in sexual problems. Some studies support horny goat
weed’s long history of traditional use. One study found that people on dialysis
for kidney failure had improved sex drives when given horny goat weed, compared
to people who did not get the herb.2 Other studies have found that
horny goat weed can restore low levels of testosterone.3
The most mysterious herb in Hard
Wine, and the one that generated the most discussion on the streets of Tobago,
is bois bandé (Richeria grandis, Phyllanthaceae). Though virtually no reliable
scientific information on this herb has been found, the authors did locate one
published interview with healers from Trinidad and Tobago in which bois bandé came up as a treatment for
ED.4
Likewise, Dr. Duke encountered an
herbal formula with a name to rival Hard Wine. Rompe calzon is a Latin American aphrodisiac that, like Hard Wine,
is soaked in wine or rum. Rompe calzon
means “bust your britches.” There are only anecdotes for this herbal formula,
however, as no studies exist. But it is intriguing that both rompe calzon and another Latin American
formula Dr. Duke encountered called siete
raices (“seven roots”) contain the Peruvian herb clavohuasca (Tynanthus panurensis, Bignoniaceae).
Could there be something to these formulae as there has been for horny goat
weed?
The biggest problem facing herbal
formulae for erectile dysfunction today, though, is not incredibility. Science
actually has vindicated a number of the traditional herbs. Instead, the most
common concern is deception and adulteration. Ignoring or distrusting the
science that suggests certain herbs really work and wanting to exploit
lucrative opportunities, some marketers are adulterating products — which claim
on the label to be natural — with unlabeled pharmaceutical ingredients. As some
responsible parties in the industry prefer to phrase this situation,
unscrupulous sellers are illegally marketing conventional pharmaceutical drugs
masquerading as herbal dietary supplements.
The problem started occurring with
increasing frequency a few years ago. In 2004, researchers found that
approximately half of 40 botanical ED products analyzed contained the active
ingredients of Viagra® (sildenafil), Cialis® (tadalafil), or Levitra®
(vardenafil).5 In another study a year later, two out of seven
natural ED products tested contained either sildenafil or tadalafil.6
Again, in 2006, sildenafil analogues (compounds with similar chemical
structures) were found in herbal products marketed for ED.7
Though probably a more common
concern when buying “herbal” ED products online than when buying them in a
retail store, the problem is both serious and ongoing. In 2011, Health Canada
warned, “An increasing problem with ‘herbal’ or ‘natural’ unauthorized products
promoted for erectile dysfunction is that they contain analogues of erectile
dysfunction drugs.”8 A year later, Health Canada issued a warning to
consumers not to buy four herbal products promoted for ED because they were
found to contain either prescription or unlicensed medicines. In 2011, the US Department
of Agriculture issued a warning that an analysis had identified a sildenafil
analogue in an herbal ED product. And in 2012, the US Food and Drug
Administration (FDA) cautioned consumers on buying dietary supplements for ED
online. An FDA Internet survey found that six of 17 products contained
sildenafil or substances similar to it, and then listed 29 products to avoid.9
The Medicines and Healthcare Products Regulatory Agency in the United Kingdom
said in 2013 that it was “advising consumers not to buy ‘herbal’ remedies sold
as a treatment for erectile dysfunction” because “evidence from around the
world suggests that such products are often adulterated with random quantities
of pharmaceutical substances.”10
Herbs Showing Efficacy for ED
Erectile dysfunction is the
inability to attain or maintain an erection sufficient for satisfactory sexual
function. Fifty-two percent of men between the ages of 40 and 70 are affected
by ED.11 The prevalence of ED is expected to increase over the next
several years until it affects 322 million men worldwide by the year 2025.12
There are several possible causes
for ED. These include depression, stress, anxiety, fatigue, diabetes,
hypothyroidism, prostate disorders, low testosterone, high estrogen,
atherosclerosis, cigarette smoking, and excessive alcohol consumption.13 In fact, some research suggests
that in 20% of ED cases the cause is psychological.14 Several
pharmaceutical drugs also can cause ED; blood pressure-lowering drugs are the
most problematic,15 but antidepressants,16,17 the ulcer
medication cimetidine,18 and the benign prostatic hyperplasia drugs
finasteride19,20 and tamsulosin (Flomax®)21 are also
common culprits.
Not all botanical manufacturers of
ED products are unscrupulous. The market also contains legitimate herbal
products that have had their botanical identity and raw materials
authenticated, and many have at least one or two well-controlled clinical
trials, or substantial history of traditional use, supporting the ED claim.
That these legitimate products should be cast under a negative shadow and that
people who could benefit from taking them are warned away is unfortunate
because ED is a serious and increasingly common problem, the pharmaceutical
solutions are not without side effects, and legitimate herbal products do offer
viable options for treatment.
Ginkgo Extract
A very promising herb for treating
ED is the standardized extract of ginkgo (Ginkgo
biloba, Ginkgoaceae) leaf. One of the most valuable and versatile of all
herbs, ginkgo is well known for its ability to increase circulation to the
extremities, including the head, hands, and feet. So it is not entirely
surprising that a condition often caused by lack of blood flow to the penis
could also be helped by ginkgo extract.
At least two studies show the
promise of ginkgo for reducing symptoms associated with ED. One study included
60 men suffering from ED caused by impaired penile arterial blood flow. For 12
to 18 months, men consumed a low dose of 60 mg per day of ginkgo extract (EGb
761®, W. Schwabe, Karlsruhe, Germany*;
50:1; 6% terpenes, 24% ginkgo flavonol glycosides). What is especially
interesting about the study is that all of the men had failed to respond to
injections of papaverine, a conventional pharmaceutical drug composed of the alkaloid
derived from opium poppy (Papaver
somniferum, Papaveraceae) that is used to improve blood flow in people with
circulatory problems. It works by relaxing blood vessels and is employed for
ED. However, its use had not benefited any of the men in this study, suggesting
that they were difficult-to-treat cases. But after only six-to-eight weeks on
ginkgo, improvement in penile arterial flow was evident. And after six months,
50% of the subjects had resolved their ED. In another 20% of the study participants,
a subsequent attempt at papaverine ED treatment was then successful.22
The second study was double-blinded
and administered the more common higher dose of 240 mg ginkgo extract (EGb
761). In this nine-month study, 50
men with arterial ED were divided into two groups: those who had experienced
some previous success with medication, and those who had not. All of the men
who had experienced some response to conventional drugs regained spontaneous
erections after six months on ginkgo. All of them had objective improvement in
erectile function, including improved rigidity at both the tip and the base of
the penis, as well as improvements in arterial flow rate. Perhaps even more
impressively, of the 30 men who had experienced no success with medications, 19
of them responded to the ginkgo. All study participants showed improved
objective response parameters.23
Ginkgo extract likely works by
improving blood flow to the erectile tissue by enhancing arterial and vascular
blood flow. Ginkgo relaxes the corpus cavernosum vascular smooth muscles. The
corpora cavernosa are the cylindrical blood sinuses that form the erectile
tissue of the penis and expand when filled with blood. Ginkgo’s effect on the
corpus cavernosum is thought to be a mechanism of action that contributes to
improvement in ED. Ginkgo extract also has vasodilating action.
Asian Ginseng Root
The herb that is generating perhaps
the most scientific support for ED is Asian ginseng (Panax ginseng, Araliaceae), which has been employed for sexual
dysfunction in traditional Asian medicine for centuries. The first important
study of ginseng and ED was published in 1995. This trial gave either 1,800 mg
of Korean red ginseng extract (extract description not given), a pharmaceutical
drug (trazodone), or a placebo to a total of 90 men with ED, with 30 men in
each group.24 Red ginseng is the same root as white ginseng, but,
whereas white ginseng is simply the dried mature root, red ginseng is the fresh
root that has been steamed for two-to-three hours before it is dried. The
steaming leads to a change in the profile of the major ginsenosides, and thus a
change in the root’s (and the extract’s) pharmacology.25 Red ginseng
is held to be “warmer” and “more stimulating,” according to the energetics
principles of Asian traditional medicine. In the aforementioned trial, the
ginseng increased erectile function in significantly more men: 60% in the
ginseng group versus only 30% in the placebo and trazodone groups (P<0.05).
Ginseng brought about significant improvement in the rigidity and width of the
erection, as well as in the ability to maintain an erection and in patient
satisfaction (P<0.05). As a bonus, it also significantly improved libido.
Though there were no complete remissions in this study, the partial improvements
were significant.
Further, in a double-blind,
placebo-controlled study, a total of 45 men with ED were given either 900 mg of
powdered Korean red ginseng or a placebo three times a day for eight weeks.
Sixty percent of the men on the ginseng had improved erections, according to
the global efficacy questionnaire. Erection scores increased by 41.7% in the
ginseng group compared to only 6% in the placebo group. The total five-part
International Index of Erectile Function (IIEF) scores were significantly higher
in the ginseng group than in the placebo group, with an improvement of 36.2%
versus 10.4% (P<0.01). Penile rigidity was significantly better in the
ginseng group. Penetration and maintenance of erection were significantly
higher in the ginseng group than in the placebo group (P<0.01). And, again,
ginseng improved sexual desire.26
Another double-blind,
placebo-controlled study gave either 1,000 mg of Korean red ginseng (presumably
dried powdered root) or a placebo three times per day to 60 men with mild-to-moderate
ED. After 12 weeks, IIEF scores had improved from 16.4+/-2.9 to 21.0+/-6.3
(P<0.0001). In the ginseng group 66.6% of the men had improved erections;
there was no significant effect in the placebo group. The ginseng was
significantly better for rigidity, penetration, and maintenance (P<0.01) as
well.27
In the first-ever systematic review
of clinical research on Korean red ginseng and ED, researchers found seven
randomized, controlled clinical studies that included a total of 363 men. In
the six studies that compared ginseng to a placebo, the ginseng improved
erectile function more than the placebo in each individual trial. Combining the
studies into a meta-analysis, the researchers found that this was not due to a
placebo effect, as the ginseng had a significant effect (P<0.00001). Ginseng
is not only effective, but safe; adverse events were scarce and mild.
Interestingly, the meta-analysis found that the red ginseng also produced
significant improvement when the ED was from psychological causes (P<0.001).28
Recent studies have postulated that
Asian red ginseng may help ED by directly inducing relaxation of the smooth
muscles of the corpus cavernosum via nitric oxide pathways.27,29
Ginseng’s mechanism of action against ED is not yet fully understood.
Muira Puama
Another potentially valuable herb
for ED is muira puama (Ptychopetalum olacoides, Olacaceae).
This potential application is no surprise in Brazil, where the herb is known as
“potency wood,” and has been used for many years. Muira puama seems to address both the physical and psychological
problems associated with impotency. A study done by Jacques Waynberg, MD, PhD,
of the Institute of Sexology in Paris, found that of 262 men suffering from ED
or lack of sexual desire, 62% of those with loss of desire were helped by
1-to-1.5 grams of muira puama extract
(not described in the study), and 51% of those with ED benefited from the herb.30
Muira puama’s efficacy for ED seems
to be due in part to its nerve-stimulating properties. The mechanism of action
of its aphrodisiac effect on sexual desire remains unknown.
Multi-Herb Combination
A recent double-blind,
placebo-controlled study combined muira
puama, Asian ginseng, and ginkgo with horny goat weed and five additional
herbs.31 The nature of these preparations was not specified or
described in the trial. Seventy-eight otherwise healthy men with
mild-to-moderate ED, scoring 11-23 on the Erectile Function domain of the IIEF,
were given a placebo or a proprietary herbal product known as VigRx Plus® (Leading
Edge Herbals; Greeley, CO). The capsules contain 100 mg Asian ginseng, 100 mg
ginkgo extract, 100 mg hawthorn (Crataegus
monogyna, C. laevigata, Rosaceae)
berry, 50 mg muira puama, 50 mg
catuaba (Erythroxylum catuaba,
Erythroxylaceae), 25 mg Chinese dodder (Cuscuta
chinensis, Convolvulaceae) seed, 15 mg horny goat weed, 75 mg tribulus
(Tribulus terrestris,
Zygophyllaceae), 100 mg damiana (Turnera
diffusa, Turneraceae), and 5 mg BioPerine® (a proprietary standardized
extract of piperine from the fruit of black pepper [Piper nigrum, Piperaceae]; Sabinsa
Corporation, East Windsor, New Jersey). The capsules were administered at a
dose of two capsules twice per day, and the study lasted 12 weeks.
The men given the herbal combination
had a statistically significant increase in erectile function compared to the
placebo group (P<0.0001). Scores on the Erectile Function domain of the IIEF
increased by nine points (16.08 to 25.08) in the herb group compared to an
increase of only 0.61 points (15.86 to 16.47) in the placebo group. Thirty-four
percent of the herb group, compared to only 3% of the placebo group, attained
erections that were always or almost always hard enough to achieve penetration.
Equally importantly, as ED is the inability to attain or maintain an erection,
the ability to penetrate and to maintain an erection after penetration improved
by 59% and 63%, respectively, in the herb group, but by only 4% and 9% in the
placebo group. Fourteen out of 39 men had scores greater than 25 by the end of
the study, indicating no presence of ED, compared to only one of 36 in the
placebo group. The men in the herb group also experienced significant
improvement compared to placebo in all other categories of the IIEF, including
sexual desire, orgasmic function, intercourse satisfaction, and overall
satisfaction. The mean increase in the total IIEF score was 20.1 in the herb
group compared to only 1.0 in the placebo group. The herbal treatment was rated
as good or excellent by 95% of men, while the placebo was rated as poor by 67%.
On the Erectile Dysfunction
Inventory of Treatment Satisfaction scale, the mean treatment satisfaction
score was 82.31 in the herb group versus 36.78 in the placebo group. The
difference in satisfaction was even greater for their partners: 82.75 in the
herb group versus only 18.50 in the placebo group. Ninety percent of the men on
the herbs wished to continue treatment compared to only 3% of the placebo
group. The herbs were not only apparently effective but presumably safe;
adverse effects were minor and similar in both groups.
Among the other herbs in the
formula, though no clinical studies exist, the herb damiana has been prized as
an aphrodisiac by Mexican cultures since antiquity. Damiana is thought to work
by slightly irritating the urethra, which increases the sensitivity of the
penis.15 Hawthorn, especially the leaf and flower extract, exerts a blood pressure-lowering effect by dilating coronary vessels,
acting as an ACE (angiotensin-converting enzyme) inhibitor and diuretic, and
increasing heart function.32 Chinese dodder is used in TCM for
impotence. Catuaba is a Brazilian herb that is a non-cocaine-containing
relative of the coca plant (E. coca)
used in the Amazon region as an aphrodisiac. Saw palmetto (Serenoa repens, Arecaceae) berry 9-12:1 ethanol extract (Prostasan®;
A. Vogel Bioforce AG; Roggwil, Switzerland) has been shown in a pilot trial to
improve sexual function by more than 30 percent in men whose ED is caused by
benign prostatic hyperplasia.33
Tribulus terrestris has been used in Ayurvedic medicine and in European folk medicine as an
aphrodisiac and for the treatment of impotence. Several studies exist to
support this traditional use.34-36 However, most of this research is
non-blinded and of questionable quality. Much of it is research on animals that
often has failed to be duplicated in human studies. For the most part, the
published research is poorly designed with results that are not definitive.
There is little in the way of well-controlled trials, making conclusions on tribulus difficult.37,38
One recent
double-blind study, however, is potentially promising because the comparison
group received the drug Cialis (tadalafil).39 The subjects in this
study were 70 men over the age of 60 with reduced libido and with or without
ED. They were given either Cialis or a supplement called Tradamixina®
(Tradapharma, Lugano, Switzerland), consisting of 396 mg of tribulus (form not
specified) combined with 150 mg of
the brown algae arame (Ecklonia bicyclis,
Lessoniaceae) and 144 mg of glucosamine
(identified as D-glucosamine and N-Acetyl-D-glucosamine) twice per day for two months. Testosterone levels increased
significantly in the tribulus combination group and non-significantly in the
Cialis group. Nocturnal erections improved in the tribulus combination group,
and total IIEF scores improved in the tribulus combination group but only
non-significantly in the Cialis group. The specific erectile function area of
the IIEF improved in both groups, but it improved more in the Cialis group; the
Sexual Quality of Life score improved in both groups, but more so in the
tribulus group. Libido improved in the tribulus group but not in the Cialis
group. The authors concluded that Tradamixina is effective for mild-to-moderate
ED in men with low testosterone and that it is free from the adverse side
effects of Cialis.
A potential
limitation of this study that somewhat interferes with drawing conclusions
about tribulus is that it was combined with other supplements. Because some of
the men in the study had ED and some did not, it would be interesting to
determine if the tribulus improved symptoms in the specific subgroup of men
with ED or whether the improvement was attributable to the observed improvement
in libido.
The primary active constituent in
tribulus is believed to be protodioscin. Protodioscin is a steroidal saponin
that is thought to convert to DHEA (dehydroepiandrosterone) and to increase
testosterone, dihydrotestosterone, and luteinizing hormone.40,41
Protodioscin may also contribute to the relaxation of the corpus cavernosum.42
Many of these actions of tribulus await confirmation in human studies.
Maca, Pycnogenol®, Rhodiola rosea, Eurycoma, Ashwagandha,
Oats, and Yohimbe
Maca. Another South American herb that may help
with ED is maca (Lepidium meyenii,
Brassicaceae), an edible tuber that grows at high altitudes in the Peruvian
Andes. In a double-blind study, 50 young men with mild ED were given either
1,200 mg of pulverized and dehydrated maca root or a placebo twice a day for 12
weeks.†43 IIEF scores
improved significantly in both groups, but they improved significantly more in
the maca group than in the placebo group (1.6+/-1.1 versus 0.5+/-0.6;
P<0.001). Subjectively, though scores on the Satisfaction Profile (SAT-5)
improved significantly in both groups, once again, the SAT-5 scores improved
significantly more in the maca group (9+/-6 versus 6+/-5 in the placebo group;
P<0.05). Further, only the maca produced significant improvement in the
physical and social performance-related SAT-5 scores. Maca also has been shown
to improve libido in healthy men.44,45
Pycnogenol®. A botanical preparation that takes a
promising approach to ED is the patented extract from French maritime pine bark
(Pinus pinaster, Pinaceae), known
commercially as Pycnogenol®
(Horphag Research; Geneva, Switzerland). For an erection to occur, the blood
vessels to the penis must dilate. Such dilation depends on nitric oxide (NO),
which triggers the relaxation of the cavernous smooth muscle. Pycnogenol has
been shown to enhance the production of NO.46,47 When researchers
gave either 120 mg of Pycnogenol per day or a placebo to 21 men diagnosed with
ED in a double-blind study, after three months, ED symptoms were significantly
improved in the Pycnogenol group (P<0.05). The placebo had no effect.
According to the IIEF-5 scoring, Pycnogenol decreased ED severity from moderate
to mild.48
Nitric oxide is dependent on the
amino acid arginine, which may hold promise for helping ameliorate ED.49
In a double-blind, placebo-controlled study, 50 men with ED were given either 5
g per day of L-arginine or a placebo for six weeks. Thirty-one percent of the
men on arginine — but only 11.7% of the men on the placebo — reported
significant improvement in sexual function. Objective variables remained
unchanged. The men who responded to the arginine had lower levels of NO at the
beginning of the study.50
The combination of these two
NO-enhancers has proven to be a promising approach to treating ED. In a study
of 40 men, one month of arginine ingestion led to normal erections in only a
non-significant 5% of the men. But when 40 mg of Pycnogenol twice a day was
added in the second month, 80% of the subjects were restored to normal
erections. And when the dose was increased to 40 mg of Pycnogenol three times a
day, the number of men who attained sexual ability increased to 92.5%. The
researchers concluded that the combination of arginine and Pycnogenol causes
significant improvement in ED without adverse effects.51
These promising results have been
duplicated in at least two more rigorously designed, double-blind studies. In
the first, 111 men with mild-to-moderate ED (IIEF score between 11 and 17) were
given either a placebo or a combination product containing 40 mg of Pycnogenol
and 1400 mg of arginine (Prelox®, Horphag Research; Geneva, Switzerland) twice
per day. After three months, the Pycnogenol/arginine group’s score on the IIEF
had increased significantly from 15.2 to 25.2; the placebo group improved from
15.1 to only 19.1. And, after six months, the Pycnogenol/arginine group’s score
had continued to rise to 27.1, while the placebo group had started to drop
slightly to a score of 19. The improvement in the Pycnogenol/arginine group was
significant compared to the placebo (P<0.05). Additionally, there was a
significant improvement in orgasmic function, sexual desire, intercourse
satisfaction, and overall satisfaction in the Pycnogenol/arginine group
(P<0.05) compared to the placebo group. Testosterone levels increased
significantly from 15.9 to 18.9nmol/L (P<0.05), but barely at all in the
placebo group.52
In the second double-blind study,
men with mild-to-moderate ED were given a supplement containing 60 mg
Pycnogenol, 690 mg L-arginine, and 552 mg aspartic acid or a placebo each day
for eight weeks. Total scores on the IIEF-5 improved in the supplement group.
There was “marked improvement” in the hardness of erection and satisfaction
with sexual intercourse items of the IIEF-5. There were no adverse reactions.
The researchers concluded that Pycnogenol combined with L-arginine is safe and
effective in mild-to-moderate ED.53
Rhodiola rosea root.
Rhodiola (Rhodiola rosea,
Crassulaceae) is a traditional herb of increasing popularity for its
adaptogenic activities. It is known for its ability to help reduce symptoms of
stress and fatigue, among other properties. With respect to ED, in one open
clinical trial, 35 men who suffered from ED, premature ejaculation, or both,
took 150-200 mg of rhodiola root extract for three months; 26 of them responded
with substantially improved sexual function.54
Eurycoma longifolia. Another
herb with a name that reflects its traditional use is longjack root, more
commonly known by the Malaysian name tongkat
ali (Eurycoma longifolia,
Simaroubaceae). This herb is commonly found in Southeast Asia. In Malaysia, it
is commonly employed as an adaptogen for general well-being and specifically as
an aphrodisiac with claims of benefit for ED. In a recent double-blind,
placebo-controlled clinical trial, researchers gave either 300 mg of
freeze-dried standardized water root extract of E. longifolia (Physta®, Biotropics Malaysia Berhad, Shah Alam,
Selangor, Malaysia) or a placebo to
109 men with no ED or only mild ED for 12 weeks.55 Scores on the
IIEF were a secondary endpoint. There was a significant improvement in erectile
function in the E. longifolia group
compared to the placebo (P<0.001). There was an 8.7% increase in the ability
to attain an erection and a 7.2% increase in penetration ability.
The important limitation of the
study, however, is that its population consisted of healthy men with no or only
mild ED; all subjects fell within the “no dysfunction range.” This limitation
leaves two possibilities: Either E.
longifolia enhances erectile function in healthy men with unknown benefit
for men suffering from ED, or the study shows that E. longifolia enhanced erectile function and may have shown even
more positive results but, because the subjects were already healthy, there was
limited possible benefit to be achieved by administering the herb. Future
research will help clarify this matter.
Ashwagandha root. When stress and anxiety are
contributing factors, nervine herbs like ashwagandha (Withania somnifera, Solanaceae) and oats (Avena sativa, Poaceae) may be helpful. Ashwagandha is an
adaptogenic root that may be useful for sexual problems related to nervous
tension. It has long been used in India as a rejuvenating aphrodisiac.
Ashwagandha contains withanolides, which act as hormone precursors that can
convert into, and perhaps balance, human hormones.56
Oats. Oats are
among the most effective tonic herbs for the nervous system, traditionally
considered to support the nervous
system while relaxing it, and have long been used as an aphrodisiac for
boosting sexual vitality. Unpublished research at the San Francisco Institute
for Advanced Study of Human Sexuality has found oat extract to be beneficial. A
double-blind study found improved firmness of erection in men with no sexual
dysfunction. A second study gave 300-600 mg oat extract to 30 men with ED.
Nineteen of them experienced a partial or complete response, with erection
ability returning to pre-impotence levels in all 19.57 Though there
is some evidence for oats as an herb for ED, the basis for the use of oats
remains mostly folkloric.58 However, several prominent herbalists
and herbal researchers continue to endorse the use of oats as an appropriate
nervine for stress and anxiety related to ED.59-61
Yohimbe. The
African tree bark yohimbe (Pausinystalia
johimbe, Rubiaceae) is a traditional aphrodisiac from which the alkaloid
yohimbine, a recognized and previously employed pharmaceutical agent for
impotence, is derived. Yohimbe is considered effective, but its myriad adverse
effects, including blood pressure and heart rate-increasing properties, inhibit
its utility.62,63
Conclusion
Though many of the attempted
folkloric solutions to ED seem improbably amusing, time and science have
strongly suggested, and, in some cases, provided compelling evidence that there
is some truth in the traditions. There is reasonable evidence supporting the
notion that traditional herbs, such as horny goat weed, muira puama, and maca, may help improve symptoms of ED. And for
some herbs — particularly Korean red ginseng, Ginkgo biloba extract, and the patented French Maritime pine bark
extract known as Pycnogenol (especially when combined with L-arginine) — the
scientific support is quite promising. Science seems to encourage the hope that
for men suffering from ED, whether the condition is of physical or psychological
origin, there is a safe and effective natural, non-pharmaceutical path to
improvement.
Linda Woolven is a master herbalist, certified acupuncturist, and solution-focused
counselor with a practice in Toronto. She is the author of several books,
including Smart
Woman’s Guide to PMS and Pain-free Periods (John
Wiley & Sons, Ltd., 2008). Together, Woolven and Ted Snider, a natural health researcher and writer, are the authors
of Healthy Herbs: Your Everyday Guide to Medicinal Herbs and Their Use (2006), The Family Naturopathic
Encyclopedia (2011), and Sex &
Fertility: Natural Solutions (2012), all
published by Fitzhenry and Whiteside Limited. They also publish The Natural
Path newsletter. Woolven and Snider can be reached at their blog at www.thenaturalpathnewsletter.com.
*Mention of the name of a company
that manufactures and/or sells a particular product or ingredient in a product
referred to in this article is not a promotion or endorsement of said
ingredient, product, or company. Mention of such information is consistent with
the general editorial policy of the American Botanical Council in reporting
pharmacological and clinical research on botanical preparations where there is
often variability in the chemistry of such ingredients or preparations from one
brand to another.
†A peer reviewer of this article
with expertise on maca has stated that there are up to 13 different phenotypes
of maca — sometimes referred to as red, black, or yellow maca — each with
various chemical profiles, and thus potentially varying biological activity.
Such distinctions are seldom made in the pharmacological and clinical
literature on maca, and thus, unless a specific phenotype is mentioned in the
original research paper, such information is not included in this review
article.
References
- Bensky D, Gamble A, Kaptchuk T. Chinese Herbal Medicine Materia Medica. Revised Edition, Seattle: Eastland Press, 1992.
- Liao HJ, Chen XM, Li WG. Effect of Epimedium sagittatum on quality of life and cellular immunity in patients of hemodialysis maintenance. Zhongguo Zhong Xi Yi Jie He Za Zhi. 1995;15:202-204.
- Low WY. Asian traditional medicine for erectile dysfunction. J Men Health Gender. 2007;4:245-250.
- Lans C. Ethnomedicines used in Trinidad and Tobago for reproductive problems. J Ethnobiol Ethnomed. 2007;3:doi:10.1186/1746-4269-3-13.
- Gratz SR, Flurer CL, Wolnik KA. Analysis of undeclared synthetic phosphodiesterase-5 inhibitors in dietary supplements and herbal matrices by LC–ESI–MS and LC–UV. J Pharm Biomed Anal. 2004;36:525-533.
- Fleshner N, Harvey M, Adomat H, et al. Evidence for contamination of herbal erectile dysfunction products with phosphodiesterase type 5 inhibitors. J Urol. 2005;174:636-641.
- Oh SS, Zou P, Low M-Y, et al. Detection of sildenafil analogues in herbal products for erectile dysfunction. J Toxicol Environ Health A. 2006;69:1951-1958.
- Adulteration of Natural Health Products. Health Canada website. Available at: www.hc-sc.gc.ca/hl-vs/iyh-vsv/med/nat-prod-adulter-eng.php. Accessed March 5, 2013.
- Hidden risks of erectile dysfunction “treatments” sold online. US Food and Drug Administration. Available at: www.fda.gov/ForConsumers/ConsumerUpdates/ucm048386.htm. Accessed March 5, 2013.
- Herbal sexual dysfunction products warnings and alerts. Medicines and Healthcare Products Regulatory Agency website. Available at: www.mhra.gov.uk/Safetyinformation/Generalsafetyinformationandadvice/Herbalmedicines/Herbalsafetyupdates/Herbalerectilesexualdysfunctionproductswarningsandalerts/index.htm. Accessed March 5, 2013
- Laumann EO, Nocolosi A, Glasser DB, et al. Sexual problems among women and men aged 40-80 y: prevalence and correlates identified in the Global Study of Sexual Attitudes and Behaviors. Int J Impot Res. 2005;17:39-57.
- Ayta IA, Mckinlay JB, Krane RJ. The likely worldwide increase in erectile dysfunction between 1995 and 2025 and some possible policy consequences. BJU. 1999;84:50-60.
- Murray MT. Male Sexual Vitality. Rocklin, CA: Prima; 1994:12.
- Tharyan P, Gopalakrishanan G. Erectile dysfunction. Clin Evid. 2006;15:1227-1251.
- Murray MT. Male Sexual Vitality. Rocklin, CA: Prima; 1994:17.
- Herman M, Goldbloom DS. Fluoxetine-induced sexual dysfunction. J Clin Psychiatry. 1990;42:25-27.
- Balon R, Yeragani VK, Pohl R, Ramesh C, et al. Sexual dysfunction during antidepressant treatment. J Clin Psychiatry. 1993;54:209-212.
- Murray MT. Natural Alternatives to Over-the-Counter and Prescription Drugs. New York NY: William Morrow; 1994:205.
- Carraro JC, Raynaud JP, Koch G, et al. Comparison of phytotherapy (Permixon®] with finasteride in the treatment of benign prostate hyperplasia: a randomized international study of 1,098 patients. Prostate. 1996;29:231-240.
- Wilt TJ, Ishani A, Stark G, et al. Saw palmetto extracts for treatment of benign prostatic hyperplasia. A systematic review. JAMA. 1998;280:1604-1609.
- Debruyne FG, Koch P. Boyle P, et al. Comparison of phytotherapeutic agent (Permixon®) with an alpha-blocker (Tamsulosin) in the treatment of benign prostatic hyperplasia: A 1-year randomized international study. Eur Urol. 2002;41:497-506.
- Sikora, R, Sohn M, Deutz FJ, et al. Ginkgo biloba extract in the therapy of erectile dysfunction. J Urol. 1989;141:188A.
- Sohn M, R. Sikora. Ginkgo biloba extract in the therapy of erectile dysfunction. J Sex Educ Ther. 1991;17:53-61.
- Choi HK, Seong DH, Rha KH. Clinical efficacy of Korean red ginseng for erectile dysfunction. Int J Impot Res. 1995;7:181-186.
- Blumenthal M (ed.). The ABC Clinical Guide to Herbs. Austin TX: American Botanical Council; 2003: 214.
- Hong B, Ji YH, Hong JH, et al. A double-blind crossover study evaluating the efficacy of Korean red ginseng in patients with erectile dysfunction: A preliminary report. J Urol. 2002;168:2070-2073.
- De Andrade E, de Mesquita AA, Claro Jde A, et al. Study of the efficacy of Korean Red Ginseng in the treatment of erectile dysfunction. Asian J Androl. 2007;9:241-244.
- Jang D-J, Lee MS, Shin B-C, et al. Red ginseng for treating erectile dysfunction: a systematic review. Br J Clin Pharmacol. 2008;66:444-450.
- Murphy LL, Lee TJ. Ginseng, sex behavior, and nitric oxide. Ann N Y Acad Sci. 2002;962:372-377.
- Waynberg J. Contributions to the clinical validation of the traditional use of Ptychopetalum guyanna. Presented at the First International Congress on Ethnopharmacology, Strasbourg, France, June 5-9, 1990.
- Shah GR, Chaudhari MV, Patankar SB, et al. Evaluation of a multi-herb supplement for erectile dysfunction: a randomized double-blind, placebo-controlled study. BMC Complement Altern Med. 2012;12:155.doi:10.1186/1472-6882-12-155.
- Pizzorno JE, Murray MT. Textbook of Natural Medicine, 4th ed. St. Louis, MO: Elsevier; 2013:695-696.
- Suter A, Saller R, Riedi E, et al. Improving BPH symptoms and sexual dysfunctions with a saw palmetto preparation? Results from a pilot trial. hytother Res. 2013;27:218-226.
- Adimoelja A. Phytochemicals and the break-through of traditional herbs in the management of sexual dysfunctions. Int J Androl. 2000;23:82-84.
- Bardin CW, Swerdloff RS, Santen RJ. Androgens: risks and benefits. J Clin Endocrinol Metab. 1991;73:4-7.
- Protich M, Tsvetkov D, Nalbanski B, et al. Clinical trial of a tribestan preparation in infertile men. Akush Ginekol. 1983;22:326-329.
- Pizzorno JE, Murray MT. Textbook of Natural Medicine, 4th ed. St. Louis, MO: Elsevier;2012:1529.
- Mackay D. Nutrients and Botanicals for Erectile Dysfunction: Examining the Evidence. Alt Med Rev. 2004;9:13.
- Iacono F, Prezioso D, Illiano E, et al. Sexual asthenia: Tradamixina versus Tadalafil 5 mg daily. BMC Surgery. 2012;12:S23.
- Gauthaman K, Ganesan AP. The hormonal effects of Tribulus terrestris and its role in the management of male erectile dysfunction—an evaluation using primates, rabbit and rat. Phytomed. 2008;15:44-54.
- Adimoelja A. Phytochemicals and the breakthrough of traditional herbs in the management of sexual dysfunctions. Int J Androl. 2000;23:S82-84.
- Do J, Choi S, Choi J, et al. Effects and mechanism of action of a Tribulus terrestris extract on penile erections. Korean J Urol. 2013;54:183-188.
- Zenico T, Cicero AFG, Valmorri L, et al. Subjective effects of Lepidium meyenii (maca) extract on well-being and sexual performance in patients with mild erectile dysfunction: a randomized, double-blind clinical trial. Andrologia. 2009;41:95-99.
- Gonzales GF, Cordóva K, Vega K, et al. Effect of Lepidium meyenii (maca) on sexual desire and its absent relationships with serum testosterone levels in adult healthy men. Andrologia. 2002;34:367-372.
- Gonzales G, Cordóva K, Vega K, et al. Effect of Lepidium meyenii (maca), a root with aphrodisiac and fertility-enhancing properties, on serum reproductive hormone levels in adult healthy men. J Endocrinol. 2003;176:163-168.
- Fitzpatrick DF, Bing B, Rohdewald P. Endothelium-dependent vascular effects of Pycnogenol. J Cardiovasc Pharmacol. 1998;32:509-515.
- Nishioka K, Hidaka T, Nakamura S, et al. Pycnogenol®, French Maritime pine bark extract, augments endothelium-dependent vasodilation in humans. Hypertens Res. 2007;30:775-780.
- Durackova Z, Trebaticky B, Novotny V, et al. Lipid metabolism and erectile function improvement by Pycnogenol®, extract from the bark of Pinus pinaster in patients suffering from erectile dysfunction—a pilot study. Nutr Res. 2003;23:1189-1198.
- Zorgniotti AW, Lizza EF. Effect of large doses of the nitric oxide precursor, L-arginine, on erectile dysfunction. Int J Impot Res. 1994;6:33-35.
- Chen J, Wollman Y, Chernichovsky T, et al. Effect of oral administration of high-dose nitric oxide donor L-arginine in men with organic erectile dysfunction: results of a double-blind, randomized study. BJU Int. 1999;83:269–273.
- Stanislavov R, Nikolova V. Treatment of erectile dysfunction with Pycnogenol and L-arginine. J Sex Marital Ther. 2003;29:207-213.
- Ledda A, Belcaro G, Cesarone MR, et al. Investigation of a complex plant extract for mild to moderate erectile dysfunction in a randomized, double-blind, placebo-controlled, parallel-arm study. BJU Int. 2010;106:1030-1033.
- Aoki, H Nagao J, Ueda T, et al. Clinical assessment of a supplement of Pycnogenol and L-arginine in Japanese patients with mild to moderate erectile dysfunction. Phytother Res. 2012;26:204-207.
- Brown RP, Gerbarg PL, Ramazanov Z. Rhodiola rosea: A phytomedicinal overview. HerbalGram. 2002;56:40-52.
- Ismail SB, Wan Mohammad WMZ, George A, Nik Hussain NH, et al. Randomized clinical trial on the use of PHYSTA freeze-dried water extract of Eurycoma longifolia for the improvement of quality of life and sexual well-being in men. Evid Based Complement Altern Med. doi:10.1155/2012/429268.
- Anon. Withania somnifera Monograph. Alt Med Rev. 2004;9(2):211-14.
- Aphrodisiacs improve sex lives of men and women: in studies at the Institute for Advanced Study of Human Sexuality. Smart Basics website. Available at: www.tasty-nuggets.com/glos.news/1nat.sex.html. Accessed July 1, 2013.
- Malviya N, Jain S, Gupta VB, et al. Recent studies on aphrodisiac herbs for the management of male sexual dysfunction—a review. Acta Pol Pharm. 2011;68:3-8.
- Duke JA. The Green Pharmacy. New York, NY: St. Martins Press; 1998:234.
- Gladstar R. Herbal Remedies for Men’s Health. Pownal, VT: Storey Books; 1999:41.
- Tierra M. The Way of Herbs. New York, NY: Pocket Books; 1998:172.
- Murburg MM, Villacres EC, Ko GN, et al. Effects of yohimbine on human sympathetic nervous system function. J Clin Endocrin Metabol. 1991;73:861-865.
- Tam SW, Worcel M, Wyllie M. Yohimbine: A clinical review. Pharmacol Ther. 2001;91:215-243.
|