ResearchPDF Available

A Critical Review of The Extenze Male Enhancement Product



ExtenZe is a highly promoted product that has been seen on television, paper ads, and the internet. According to the ExtenZe website (, 2008), their product is a “male enhancement” pill. The concept of “male enhancement” appears to relate to the claims on their site that their product helps men maintain erections, improves ejaculate emissions, as well as increases sexual pleasure (, 2008). This paper is a critical review of the ExtenZe product. We will take a critical look at many of the various scientific claims that the ExtenZe marketers make as it relates to their product, as well as, analyze methods utilized to convince the public to buy their product.
October 31st , 2011
Reginald V. Finley Sr
Critical Thinking
Fall 2011
Professor David Terry
A critical review of ExtenZe: Male Enhancement Product
Product Website:
Fig. 1. (2011), ExtenZe Web Advertisment,
Retrieved from
INTRODUCTION …................................................................................................. 3
THE SCIENCE HOOK …......................................................................................... 3
THE CLAIMS …....................................................................................................... 4
THE AUDIENCE ….................................................................................................. 6
PROMOTION …....................................................................................................... 7
CLINICAL TRAILS ….............................................................................................. 8
APPEALING TO EMOTION …................................................................................ 10
COMPOSITION …..................................................................................................... 11
NON-SENSE …........................................................................................................... 15
OTHER CRITICISMS ….......................................................................................... 16
DANGERS …............................................................................................................... 17
CONCLUSION …......................................................................................................... 19
REFERENCES …......................................................................................................... 20
ExtenZe is a highly promoted product that has been seen on television, paper ads, and the
internet. According to the ExtenZe website (, 2008), their product is a “male enhancement”
pill. The concept of “male enhancement” appears to relate to the claims on their site that their product
helps men maintain erections, improves ejaculate emissions, as well as increases sexual pleasure
(, 2008). This paper is a critical review of the ExtenZe product. We will take a critical look
at many of the various scientific claims that the ExtenZe marketers make as it relates to their product,
as well as, analyze methods utilized to convince the public to buy their product.
In a description of the product found at the “How it Works” page( 2008), they use
terminology alluding to the idea that their product is in some way associated with the science of
medicine and has some biologically relevant foundation:
“ExtenZe is a medically created blood flow stimulator which is extremely very safe and most effective and
importantly it is made with all natural ingredients that do not contain any drugs, making most of a man's
natural penile potential. There are three erectile chambers in the male penis that Create the penis body. And
it is only when these penile chambers are sexually aroused that the blood flow does increase and the outflow
decreases. This really produces a big human male erection of the penis. A male's penis becomes much bigger
when more of this blood is pumped into these three penile chambers. ”
The very first sentence of the paragraph uses scientific terminology when it states that the
ExtenZe product is “medically created”. Questions to consider: What does this term mean in this
context? Is it created with the intent of being used as a medicine? Was it created using processes known
in medicine production facilities? We just don't really know what is meant by this as the article doesn't
specify. We can infer however that the attempt is to lure/hook those that value science-sounding speak
to purchase the product.
The statement informing us that ExtenZe is a blood-flow stimulator doesn't really tell us very
much. In what ways does it stimulate blood flow to allow a reversal of Erectile Dysfunction(ED)? Does
it narrow the blood vessels thereby increasing the blood pressure? Is it thinning the blood? Is it directly
affecting vascular tissue; but if so, what are the implications of its effect on heart tissue? It seems that
figuring out how it works is left to the reader. Other critical questions that immediately come to mind
are: What chemicals are used in this product? How is it that its alleged “natural” make-up is somehow
better at maximizing an erection? Is it truly a safe product?”
At the end of the paragraph, we are informed about basic penis physiology which could be
interpreted as a way to convince potential buyers that the ExtenZe product makers are knowledgeable
in some way as is relates to ED.
The website makes a wide variety of claims that need to be substantiated. The site states
that their product can:
Enlarge the penile erection and penis size
Way more larger and frequent erections
More intense orgasms and cumshots will be experienced
The penile erection is quicker to obtain and more reliably
The desire, performance and pleasure is enhanced significantly
Does improve endurance, sexual pleasure and penile tip sensitivity
Now can enjoy stronger and longer lasting erections
The use of absolutism in descriptions of the efficacy of the product should alert a buyer right
away. There should at least be a Caveat emptor acknowledging that not all participants will experience
the same results. Even the most irresponsible of late-night infomercial kings will at least provide a
disclaimer. The author's grammar, misspellings, and word-choice as well seem a bit odd for
professionals(see underlined above). These kind of statements and wordings don't reflect a
professional, medical-oriented outlook.
Other exaggerated claims that any reader should be skeptical of:
“A man's penis will become bigger in just a few short weeks of taking ExtenZe pills”
This is another absolute claim. How can any honest medically related agency make such a claim?
Erectile Dysfunction could be the result of multiple causes such as nerve damage, psychological issues
or major circulatory problems(Lovy, 2011). This being the case, even if ExtenZe has proven some
efficacy, it may not work for all groups of men. With negligent statements like these, they are
promising a 100% success rate, which is medically impossible.
“ExtenZe pills definately help to overcome erectile dysfunction!”
What exactly does, “definately[sic] help” mean? My children can definitely help to wash my car, this
doesn't mean that they'll do a good job or are even successful in washing my car. This ambiguous
language seems to contradict their more absolute stance with regard to their products efficacy.
The promoters of this product appeal to those groups of people concerned with side-effects and
the use of drugs by stating that their product is “made with all natural ingredients”. Firstly, the
statement, “made with all natural ingredients” doesn't necessarily mean that the entire product is fully
“all natural”. It could also mean that the product simply contains some all-natural ingredients. The
suggestion that because their product is natural then it must be safe is a logical fallacy and
irresponsible. Just because something is “all natural” doesn't mean that it is safe. Too much of an “all-
natural” product can kill just as easily as a synthetic product. It appears that dosages and efficacy
should be the concern; however, without valid scientific studies, supplement companies that push
products/drugs such as these can endanger lives. Many natural supplement companies don't reveal
exactly how much of a substance you are getting and this can be extremely dangerous.
The promoters argue that the ExtenZe pill isn't a drug; yet, it contains “natural ingredients” that
produce a desired effect. Any chemical placed in the body that produces an altered desired effect is in
fact a drug (Drugs, n.d.). A normal effect of aging in a number of men is to suffer a form of erectile
dysfunction (Erectile Dysfunction, n.d.); thus, it could be argued that manipulating one’s natural system
to reverse this effect via chemical use, is in fact taking a drug. The ExtenZe marketers make no
distinction between natural drugs and synthetic drugs. The reason is speculative but readily apparent as
they may wish to avoid the stigma of placing drugs in the body; though this is exactly what would be
occurring if ExtenZe is to effectuate a result.
The promoters of this product market their product as safe. They continuously discuss it's safety
via their ads by pushing it's alleged “natural” make-up, of which we analyzed earlier and will again in
the Composition section (p. 11). Conducting a search for the “truth of Extenze” reveals a number of
sites that do nothing more than further promote the product without any evidence of its claims. One
website, for instance, is obviously a marketing arm for their product. Another site
DiscountExtenzeonline.c om has a similar design and feel as the site. It also seems
rather apparent that this is another marketing arm for the ExtenZe product line. comes
up when you google search “Extenze composition”. intercepts you when you google
“Extenze dosage” and is once again a marketing arm for the product. The information is sometimes
copied and pasted from site to site. A search for “chemical analysis of ExtenZe product” brought up a
site that is an obviously fake review of the product as it's filled with a plethora of marketing buzz
words: .
While conducting my research I did finally bump into a site by a blogger who took ExtenZe for
a month and decided to post his results (Dyrko, 2008.). He reports no significant change; that it's “a
failure”. Unfortunately, blogs like his get drowned out by the plethora of promotional sites that
ExtenZe has built up. The internet researcher would have to search for “Extenze Scam” or “Extenze
fraud” to find contradicting information.
With so many sites making a concerted effort to market ExtenZe, it becomes uncomfortably
obvious that ExtenZe is designed to be a money making machine by any means necessary. Every
ExtenZe site I analyzed lacked scientific rigor, and promoted gross irresponsibility when it came to
consumer safety. Every site reviewed boasted a 95 to 100% efficacy and 0% risk or side effects.
Another site discovered is On their how it works page, it is much shorter, makes less
claims, provides less scientific sounding descriptions and doesn’t mention any ingredients. This is a
very smart move by the ExtenZe franchise; however, since their .net domain still has the bulk of the
information that we are reviewing, we will maintain our analysis on the information maintained at the site.
Extensive internet and database searches for any clinical studies for this product reveal only one
alleged clinical study(ExtenZe Clinical Study, 2004), which doesn't typically fit the profile of respected
clinical trials that are posted online. It uses buzz words and marketing jargon to describe the product.
The sample size was extremely low (just 20 participants) and the results of the product was based on
alleged consumer feedback. This alleged clinical study is hosted by a web marketing company located
at The only evidence for the efficacy for this product are via anecdotal or
personal testimonies for how this product has changed peoples lives. Again, these studies are unreliable
due to experimenter bias. The study in Section A of the results states:
“The increase in sexual thoughts and fantasies rose with statistical significance in all participants taking
ExtenZe once a day.”
Of course it did. The subjects are talking ExtenZe pills daily with the belief that it will enhance
performance. Was that statement even needed? Certainly, it is feasible that as a result of using and
believing in ExtenZe, that one can develop positive psychological and possibly physiological effects, at
least in the short-term(Placebo Effect, 2011). This however is a far cry from stating that the ExtenZe
product itself contains any actual elements that improve sexual performance. Just believing that it will
work alone may account for the alleged positive effects of the drugs. Also, however, the actual
testimonies themselves could have been contrived. There is really no real reason for the causal
investigator to believe the testimonies.
The study ends with this statement:
“This study shows that the all natural pro-sexual herbal and male pro-hormone sexual nutrition
supplement ExtenZe boost sexual desire, sexual energy and sexual passion. The study reveals
that sexual power, sexual pleasure and sexual performance are significantly enhanced by taking
ExtenZe for at least eight weeks. Taking ExtenZe for eight weeks revealed a highly significant
overall sex life improvement. Based on the encouraging positive outcomes of this study, a double
blind placebo-controlled clinical trial is currently in progress. ExtenZe promotes better sex. In our opinion,
better sex promotes a healthier and longer life.”
Notice that this study reflects many of the same kinds of marketing jargon as in previous examples . It
also contains many uncommon referents that we are supposed to take for granted, such as, “sexual
power” and “pro-sexual”? The authors have concluded that “better sex”, resulting from ExtenZe, can
increase one's life span; however, nothing in the study even advances support for such a claim. Lastly,
the article was at least honest in admitting that there is no double-blind, placebo controlled clinical
study. But even that statement is suspicious in that if one does a google search for “double-blind,
placebo-controlled clinical trial, ExtenZe”, the study is in the top 5 results. The ExtenZe camp are
marketers. I don't think the entry into the paper about a double-blind placebo controlled clinical trail
was an accident. Those searching the net for evidence but are unfamiliar with real clinical studies may
think that the glorified ad for ExtenZe was a true scientific study.
Lastly, it was discovered that one of the experimenters and authors of the “study”, a Dr. Stein, is
one of the founders of the ExtenZe product and has a personal and financial interest in ensuring the
viability of this product. Though he died in April, 2011, the ExtenZe camp is still using his visage to
attract customers without even a mention that he is dead. Out of his own mouth at the website, he claims that he “has researched the ExtenZe formula” and
found that it can make the male penis larger. Unfortunately for Dr. Stein, the “research” in question
contained no critical elements and lacked scientific rigor. The “study” was also done improperly at best.
The only study which could have provided scientific evidence for the efficacy of ExtenZe has been
revealed to be useless. At this point, there is no scientific evidence.
The site appeals to emotions by attempting to bring you down in the hopes of
building you back up. This is seen in many self-improvement style commercials on television. As an
example, there's a particular product I remember seeing on television that's suppose to get rid of
“unwanted” body fat. Before providing you with the miracle savior to rescue you, they break you down
first, reminding you of your perceived flaw(s). “Over the years, fat collects in this troublesome area and
it just gets worse. Our product can stop this.” The ExtenZe promoters do something similar. They tear
you down first, then they build you back up with a convenient crutch which is the savior of all your
erectile ills:
“Most erectile dysfunction treatment remedies have been really carefully created to help any men of all ages
and to put an end to this quite embarrassing condition for good.” &
“A man can definately learn everything he needs to know about putting a stop to their devastating erectile
dysfunction today.”
The rather inconspicuous message here is that you aren't really quite a man until you take care of your
problem by purchasing this product. Here's another one:
“... their inate ability to achieve an erection and to have good sex I...”
I really don't know why the authors of this page didn't use spell-check, but I digress. The
message is clear here. 'Good sex' is dictated by achieving an erection. The authors have just defined
“good sex” for their readers. Who wouldn't want good sex right? Final example:
“A man will not be paying anymore attention about their erection problems. Men who have used some cheap
impotence cure at home do say that this treatment option is so powerful, just like a health crash course - but
they get hard once or rock hard and just from getting smiled at by a somewhat pretty girl!
Was this really necessary? Of course the message here is essentially, “Yeah, we may be a tad bit
more expensive than those other guys, but at least pay for something that works right?”. They are
appealing to our common sense here but the comment about the pretty girl once again wasn't indicative
of professionals. There are mixed messages here about who the product is supposed to be for. The way
the ad reads is almost as if they are trying to appeal to teenagers.
ExtenZe is a proprietary blend (Brink, 2007), as a result of this, no individual ingredient
amounts are shown on the label. How can consumers make good decisions about what they are buying
or even if it's safe if there are no dosage information per ingredient? Even a physician couldn't tell you
what is safe or not without knowing the exact amounts you are ingesting. The ExtenZe site gives an
alleged list of various chemicals that is contained in their pills. They state:
“The following are herbal extracts for people taking alternative remedies for erectile dysfunction (contained
in ExtenZe):”
Please notice that last statement in parenthesis. It is obvious that the reader is suppose to believe
that firstly, all of the ingredients they list do help with Erectile Dysfunction and two, that ALL of the
those ingredients are in ExtenZe. Of course, since ExtenZe has all of these ingredients, the buyer
should expect major results, right? I will go down the list itemizing a few ingredients and fact checking
their claim:
1.) Yohimbe: It does appear that there are studies which show some positive benefits by using
Yohimbe but the results are not consistent and minimal effects have been observed(Saenz de
Tejada, 2000) .
2.) Gamma-Butyrolactone (GBL). They say,“GBL is found in products marketed for improving
sexual function (Verve, Jolt).” This is a truly a smart move by their legal team. Indeed, it is
marketed as such by some other companies, but this doesn't mean that it works. Every scientific
website I have read about the product shows that it is extremely dangerous, especially when
mixed with Alcohol (Zvosec. Et al, 2001).
3.) Gingko. Ginko Biloba is an extract derived from a tree found primarily in Asia. It appears that
that there is some evidence that Gingko may assist with memory and dementia but not so much
for Alziehmers (Gingko, n.d.). Including Gingko into the formula (or at least listing it)probably
had nothing to do with sexual performance but more about riding the wave of popular
4.) L arginine (also called arginine). Arginine is an amino acid, that when exposed to the proper
enzymes, can be broken down into Nitrous Oxide, a potent vasodilator (Rajfer et al, (1992).
Nitrous Oxide causes dilation of the arteries in the penis, thus establishing and maintaining an
erection. This is actually how Viagra, Levitra, and Cialis works (Lovy, 2011). We have used
Arginine with some success on certain conditions of spasms of the arteries that lead to the heart.
When exploring the topic on pubmed (medline's database), the use of Arginine as a single
Nitrous Oxide donor did not lead to a significant change in erectile dysfunction(Klotz et al,
1999, Chen et al, 1999). Some subsequent studies did show some success, but this was
combined with other chemicals that activated the conversion to NO (Nitrous Oxide). In most
renowned systematic reviews of erectile dysfunction, the use of Arginine is not even mentioned
as an acceptable or viable treatment option. This is probably due to a study which showed that
high levels of Arginine was only effective at providing an erection in subjects with abnormal
nitric oxide metabolism, such as those associated with cardiovascular disease (Freeman, 2010).
In addition, as is the issue stated earlier, we are not given any information in the ingredients
regarding the proper dosing of Arginine.
5.) Astragalus is an amazing plant with some great potential in cellular manipulation research, but
it is potentially dangerous as it increases blood pressure and blood sugar levels. Some species
are neurotoxic(Astralagus, n.d.).
There are many more ingredients apparently
within this product. The pattern of dangerous
side-effects repeat over and over again with
each ingredient. If it's not dangerous, it's
simply another bandwagon ingredient that is
marketed to treat other ailments. In searching
for the actual ingredients inside ExtenZe, I
managed to find a Supplement Facts label, as
opposed to Nutrition Facts apparently.
Thanks to another one of their marketing sites, we are provided a label to
scrutinize (see right):
It appears that they have no qualms about revealing to us that DHEA and Pregnenolone is in the
product which we will cover in the Dangers section. Vitamin amounts in mcg's are given. Notice that
the term “Active Ingredients” is no where on the label. Also, each individual amount of the ExtenZe
blends are not listed. Notice that the Sexual Response Enhancement Blend is claiming that you are
getting 600mg per serving of a variety of chemicals. The consumer could in fact be getting 599mg of
Deer Antler and 1mg total of everything else. The consumer has no way of knowing. Many of the other
ingredients listed, allegedly increase libido, heart rate, cause erections, sex drive etc. The assumption
that they wish for the consumer to have is that, if one were to ingest a mix of all of these beneficial[sic]
ingredients, then something positive must happen! In fact however, the ingredients themselves could
interfere with each other or increase certain reactions with other prescription medications.
Some things said on the site just don't make any sense. We will take a short tour through a number of
contradictions and ridiculous claims:
“ExtenZe pills today are the best natural formula making it THE most effective and normal way to get an
increase on a man's penis size and to enhance overall sexual desire along”
If you are taking pills to fix a problem, how can it be normal?
“The more angles you do attack your erectile dysfunction with, then the more likely you are really going to
put an end to your condition sooner and for good this time. Vitamins, herbs, supplements, dieting, breathing
techniques are definite things not to avoid.”
This is dangerous non-sense. As mentioned earlier, mixing all of these “natural solutions” could
contraindicate. It's irresponsible to tell anyone to try multiple methods to achieve a similar goal when it
involves ingesting chemicals to generate a physiological response.
“Natural remedies are a proven method that is guaranteed to work. No side effects. These remedies offer a
sure and safe and permanent solution to stop this erectile condition permanently. You will then definately not
become very dependent on any type of drugs. Will definately not affect other used medications that are taken.
No weekly drug bills. A man can definately learn everything he needs to know about putting a stop to their
devastating erectile dysfunction today.”
At this point, it should be more than obvious to the casual reader and critical thinker what's wrong with
the above paragraph. I have underlined the statements and phrases I find troubling. Advocates for
consumer awareness and for the protection of consumers are assuredly as disturbed as I upon reading
such carelessness. I find it despicable that supplement providers can get away with making so many
harmful claims. The passage speaks for itself at this point. I don't think there's a need to go over every
point. The passage above reflects, once again, the pattern of reckless absolute claims, dangerous
claims, and lack of scientific evidence. The old adage, “If you say it enough times people will start to
believe it's true”, unfortunately, is probably true.
The grammar and English of this article is atrocious. The author of the ExtenZe how-to page
doesn't appear to have a good grasp of the English language. This isn't an attack on the intellect of the
author, but rather the professionalism that a company should exude if they are trying to convince you to
swallow a pill that can alter your bio-chemistry. There are a multitude of egregious spelling and
grammatical errors that could have been fixed via a simple word processing program.
The webpage at has a decent review of the ExtenZe
product and brings up a number of legal issues that the company owner has faced due to false
advertising and a lack of proof that the product works.
Dr. Stephen Barrett revealed that the ExtenZe manufacturers have already lost prior lawsuits in
which the Orange County District Attorney's Office (OCDA) in California obtained a $1.75 million
settlement against Biotab Nutraceuticals (Barrett, 2011) . Not surprisingly, the lawsuit involved false
advertising which involved the lack of a scientific basis for their claims about penis enlargement.
Another lawsuit involved a class-action lawsuit against Biotab for massive frauds against the people
(Williams, E. et al vs Biotab, 2009). The defendants needed to substantiate their claims that ExtenZe
improves penis size and male sexual prowess which it could not. Dr. Barrett points out that apparently
ExtenZe at one time referred to their products as "ambesium labidrol" and "aunctus philtrum". These
products were fictitious nomenclatures created to sound like scientific terminology!
Family Practitioner, Dr. Jon Lovy in a phone interview with me dated 10/27/2011, stated:
“First off, lets start with the actual problem of sexual/erectile dysfunction. Bear in mind that this is a
syndrome, and not a disease. The difference is that a syndrome is a constellation of signs and symptoms that
point to a pathology, without actually addressing what the specific cause of the pathology is. A disease is the
actual tissue diagnosis that is causing the pathology or syndrome. ED can have a wide variety of causes or a
specific cause that taking a pill may not fix. Claiming an almost 100% success rate is irresponsible.”
The ExtenZe site takes some time to describe the various chemicals that are in its product and
their supposed medicinal application. Let's remember that the Extenze creators have stated that with
their product, “.. there are no negative side effects”. Let's address two chemicals “Pregnenolone and
DHEA. Pregnenolone has no evidence of efficacy in treating ED. Pregnenolone is a chemical in the
body that is used to make all steroid hormones. Cholesterol is converted to Pregnenolone and
Pregnenolone can be converted in turn into DHEA (Walter, 2002). There are are no clinical studies that
I have been able to find that substantiate the idea that Pregnenolone alone has anything to do with
staying erect. I'd argue that this is simply another attempt at jumping on the supplement bandwagon as
Pregnenolone is very popular among bodybuilders. There is some evidence that the use of DHEA in
patients who are found to have a low level of this hormone in the blood had some beneficial effects on
erectile dysfunction; however, due to long-term concerns about safety, most experts do not recommend
its use(Lovy, 2011). In any case, the claims that there are zero side effects or drug interactions are
highly deceptive because of the known effects of DHEA on acne, liver disease, hair loss, palpitations,
hormone sensitive cancers, mood disorders, abdominal pain, and cardiac arrhythmia(Lovy, 2011). As
Pregnenolone frequently converts to DHEA, the consumer may inadvertently receive a higher dose of
DHEA than expected.
There are other dangers associated with ExtenZe that aren't related to just health. Career and
reputation could be tarnished as well taking ExtenZe . In April 2010, LaShawn Merritt, an Olympic
gold medalist was banned from competition for taking ExtenZe, due to the DHEA in the formula. Of
course DHEA (Dehydroepiandrosterone) is a steriod that is banned from athletic competition. Merritt
attempted to explain that he was unaware that it contained the chemical but was still banned (Shipley,
From the ExtenZe website, it provides a brief disclaimer but of course understates its
“In a man, some Occasional erectile dysfunction is quite normal. But if this erectile dysfunction keeps
happening for longer than two months or is a very recurring problem, please see your doctor for a physical
re-evaluation. Also please discuss with the professinal doctor any male enhancement questions in regards to
using herbal supplements. Then he or she will for sure help you weigh the obvious pros and cons of any
herbal treatments for erectile dysfunction based on your medical history.”
This statement is quite misleading in that it’s assuming that a doctor would actually recommend herbal
treatments, especially the likes of ExtenZe, for “male enhancement”. They wish for the reader to
assume the same.
The available evidence leads to the conclusion that this product probably doesn't work. A lack
of scientific rigor supporting the products efficacy, contradicting evidence regarding product safety, and
rampant absolute statements disallows this product as meeting the standards of conducting good
science. Good science provides a level of falsifiability, structured analysis, and honesty. Good science
also provides peer-reviewed studies that other scientists can replicate (What is Good Science?, n.d). We
see all of that and more lacking with the Extenze product. Though there is plenty of science wording in
the Extenze promotional efforts, there is really no science at all in their methods. As there are no
scientific methodologies employed in the ExtenZe product, one should be cautious if considering
partaking in this product. I am not a physician; however, based on the evidence, I would never
recommend Extenze to anyone.
Astralagus. (n.d.). In Wikipedia. Retrieved October 26th, 2011, from
Barrett, S (2011) Dietary Supplement Maker to Pay $1.75 Million
for Unfair Business Practices, Including Falsely Promising Male Penile Enlargement, Retrieved
October 31st, 2011 from
Brink, W (2007) The Truth about “Proprietary” Blends in Nutritional Supplements, Retrieved October
30th, 2011 from
Chen J, et al (1999) Effect of oral administration of high-dose nitric oxide donor L-arginine in men
with organic erectile dysfunction: results of a double-blind, randomized, placebo-controlled
study. BJU Int. 1999 Feb;83(3):269-73.
Dr. Jon Lovy, personal communication, October 23rd, 2011
Drug (n.d) In Wikipedia, Retrieved October 22nd, 2011, from
Dyrko, D. Extenze One Month Later, Retrieved October 30th, 2011, from
Erectile Dysfunction (n.d.) In MedicineNet, Retrieved October 18th, 2011, from (n.d.) How it Works, Retrieved October 28th, 2011 from (2008) How It Works, Retrieved October 29th, 2011 from
ExtenzeTruth (n.d.) How it Works, Retrieved October 28th from
Freeman, D. (n.d.). Natural Remedies for Erectile Dysfunction, Edited by Dr. Louise Chang
Gamma-Butyrolactone (n.d.) In Wikipedia, Retrieved October 30th, 2011, from
Gingko Biloba (n.d) In Wikipedia. Retrieved October 27th, 2011 from
Klotz et all (1999) Effectiveness of oral L-arginine in first-line treatment of erectile dysfunction in a
controlled crossover study. Urol Int. 1999;63(4):220-3.
Placebo Effect (n.d.) In Skeptic Dictionary, Retrieved October 30th, 2011 from
Rajfer, J., W. J. Aronson, et al. (1992). "Nitric Oxide as a Mediator of Relaxation of the Corpus
Cavernosum in Response to Nonadrenergic, Noncholinergic Neurotransmission." New England
Journal of Medicine 326(2): 90-94.
Saenz de Tejada, et al (2000) Regulation of pre-synaptic alpha adrenergic activity in the corpus
cavernosum, Retrieved October 29th, 2011 from
Shipley, A. (2010, April 23). Olympic 400-meter champ LaShawn Merritt tests positive for steroid.
Washington Post, Retrieved October 30th, 2011 from
Stein, D., Frasure, B. (2004) ExtenZe Clinical Trial, Retrieved October 28th, 2011 from
Walter L, M. (2002). "Androgen biosynthesis from cholesterol to DHEA." Molecular and Cellular
Endocrinology 198(1-2): 7-14.
What is good science? (n.d) DinoScience, Retrieved October 30th, 2010 from
Zvosec, D. L., S. W. Smith, et al. (2001). "Adverse Events, Including Death, Associated with the Use of
1,4-Butanediol." New England Journal of Medicine 344(2): 87-94.
ResearchGate has not been able to resolve any citations for this publication.
Nitric oxide has been identified as an endothelium-derived relaxing factor in blood vessels. We tried to determine whether it is involved in the relaxation of the corpus cavernosum that allows penile erection. The relaxation of this smooth muscle is known to occur in response to stimulation by nonadrenergic, noncholinergic neurons. We studied strips of corpus cavernosum tissue obtained from 21 men in whom penile prostheses were inserted because of impotence. The mounted smooth-muscle specimens were pretreated with guanethidine and atropine and submaximally contracted with phenylephrine. We then studied the smooth-muscle relaxant responses to stimulation by an electrical field and to nitric oxide. Electrical-field stimulation caused a marked, transient, frequency-dependent relaxation of the corpus cavernosum that was inhibited in the presence of N-nitro-L-arginine and N-amino-L-arginine, which selectively inhibit the biosynthesis of nitric oxide from L-arginine. The addition of excess L-arginine, but not D-arginine, largely reversed these inhibitory effects. The specific liberation of nitric oxide (by S-nitroso-N-acetylpenicillamine) caused rapid, complete, and concentration-dependent relaxation of the corpus cavernosum. The relaxation caused by either electrical stimulation or nitric oxide was enhanced by a selective inhibitor of cyclic guanosine monophosphate (GMP) phosphodiesterase (M&B 22,948). Relaxation was inhibited by methylene blue, which inhibits cyclic GMP synthesis. Our findings support the hypothesis that nitric oxide is involved in the nonadrenergic, noncholinergic neurotransmission that leads to the smooth-muscle relaxation in the corpus cavernosum that permits penile erection. Defects in this pathway may cause some forms of impotence.
To determine, in a prospective randomized, double-blind placebo-controlled study, the effect of 6 weeks of high-dose (5 g/day) orally administered nitric oxide (NO) donor L-arginine on men with organic erectile dysfunction (ED). The study included 50 men with confirmed organic ED who were randomized after a 2-week placebo run-in period to receive L-arginine or placebo. A detailed medical and sexual history, O'Leary's questionnaire, a specially designed sexual function questionnaire and a sexual activity diary were obtained for each patient. All participants underwent a complete physical examination including an assessment of bulbocavernosus reflex and penile haemodynamics. Plasma and urine nitrite and nitrate (designated NOx), both stable metabolites of nitric oxide, were determined at the end of the placebo run-in period, and after 3 and 6 weeks. Nine of 29 (31%) patients taking L-arginine and two of 17 controls reported a significant subjective improvement in sexual function. All objective variables assessed remained unchanged. All nine patients treated with L-arginine and who had subjectively improved sexual performance had had an initially low urinary NOx, and this level had doubled at the end of the study. Oral administration of L-arginine in high doses seems to cause significant subjective improvement in sexual function in men with organic ED only if they have decreased NOx excretion or production. The haemodynamics of the corpus cavernosum were not affected by oral L-arginine at the dosage used.
Relaxation of cavernous smooth muscle is a parasympathetic and non-adrenergic, non-cholinergic mediated process which requires nitric oxide (NO). NO is synthesized from L-arginine by NO synthase (NOS). Some studies report good clinical results under oral L-arginine medication in the treatment of erectile dysfunction. We examined the effectiveness and safety of L-arginine in the treatment of mixed-type impotence. 32 patients (mean age 51.6 years) with mixed-type impotence diagnosed according to the results of sexual history and urological examination were enrolled in a randomized, placebo-controlled, crossover comparison of an oral placebo with 3 x 500 mg L-arginine/day. A validated questionnaire (KEED) was used to define the grade of impotence with a score. The treatment consisted of two 17-day courses (50 tablets). After a 7-day washout period the patients who initially received the placebo for 17 days were switched to L-arginine and vice versa. We assessed the efficacy with the validated questionnaire at the end of each drug period. 30 patients (94%) completed the whole treatment schedule. Five (17%) patients reported a significant improvement in erectile function at the end of the L-arginine phase and 6 (20%) patients after the placebo period. 17 (56%) patients showed little improvement with L-arginine and 13 (43%) with placebo. In 8 patients (27%) of the verum group there was either no change in the ED score or even a slight worsening. No statistical difference in the impotence scores were found. No drug-related adverse effects occurred with L-arginine treatment. Oral L-arginine 3 x 500 mg/day is not better than placebo as a first-line treatment for mixed-type impotence.
The neurotransmitters and vasoactive substances regulating tone in the smooth muscle of the penile arteries/arterioles and the trabeculae of the corpora cavernosa are critical mediators of the state of penile erection. Contemporary research reveals a coordinated, intricate interplay between the pathways of vasorelaxation and vasoconstriction representing a most efficient physiological mechanism to initiate and maintain penile erection. This paper will focus on the role of the adrenergic constrictor pathways in penile erection and, more specifically, on the pre-junctional adrenergic mechanisms that regulate smooth muscle constriction. All neurogenic constrictor responses are related to the release of norepinephrine from adrenergic nerves that act on post-junctional alpha-1 and pre-junctional and post-junctional alpha-2 receptor subtypes. Based on the current state of knowledge, there are at least three pre-junctional mechanisms regulating penile smooth muscle tone. First, norepinephrine release from the adrenergic nerves binds to the pre-junctional alpha-2 adrenoceptor on the adrenergic nerves and negatively regulates norepinephrine release. Blockade of this reaction by selective alpha-2 receptor antagonists (e.g. yohimbine or delequamine) will enhance norepinephrine release. Second, norepinephrine release from the adrenergic nerves binds to the pre-junctional alpha-2 adrenoceptor on the non-adrenergic, non-cholinergic (NANC) nerves and inhibits nitric oxide synthesis and release. Blockade of this reaction by selective alpha-2 receptor antagonists (e.g. yohimbine or delequamine) will enhance nitric oxide release, facilitating erection. Finally, cholinergic nerves pre-junctionally inhibit norepinephrine release from the adrenergic nerve and stimulate the NANC nerve to increase nitric oxide synthesis and release. These observations indicate that different neurotransmitters regulate the adrenergic neurotransmission pathway. Based on the above concepts for pre-junctional and post-junctional regulation of smooth muscle tone, the most efficacious strategy to reduce adrenergic activity and facilitate penile erection is to combine alpha-1 and alpha-2 adrenergic receptor antagonists. In this case, any enhancement of norepinephrine release is of little importance because the alpha-1 receptor antagonist will impede this vasoconstrictor response. This will also enhance the release of nitric oxide, which increases smooth muscle relaxation and decreases contraction resulting in penile erection.
Androgens and estrogens are made from dehydroepiandrosterone (DHEA), which is made from cholesterol via four steps. First, cholesterol enters the mitochondria with the assistance of the steroidogenic acute regulatory protein (StAR). Mutations in the StAR gene cause congenital lipoid adrenal hyperplasia. Second, within the mitochondria, cholesterol is converted to pregnenolone by the cholesterol side chain cleavage enzyme, P450scc. Third, pregnenolone undergoes 17alpha-hydroxylation by microsomal P450c17. Finally, 17-OH pregnenolone is converted to DHEA by the 17,20 lyase activity of P450c17. The ratio of the 17,20 lyase to 17alpha-hydroxylase activity of P450c17 determines the ratio of C21 to C19 steroids produced. This ratio is regulated post-translationally by at least three factors: the abundance of the electron-donating protein P450 oxidoreductase, the presence of cytochrome b(5), and the serine phosphorylation of P450c17. Study of these and related factors may yield important information about the pathophysiology of adrenarche and the polycystic ovary syndrome (PCOS).
Jon Lovy, personal communication
  • Dr
Dr. Jon Lovy, personal communication, October 23 rd, 2011
com (n.d.) How it Works, Retrieved October 28 th
  • Extenze (n.d.) How it Works, Retrieved October 28 th, 2011 from
How It Works, Retrieved October 29 ExtenzeTruth (n.d.) How it Works
  • Extenze (2008) How It Works, Retrieved October 29 th, 2011 from ExtenzeTruth (n.d.) How it Works, Retrieved October 28 th from