The largest amounts of testosterone (>95%) are produced by the testes in men,[2] while the adrenal glands account for most of the remainder. Testosterone is also synthesized in far smaller total quantities in women by the adrenal glands, thecal cells of the ovaries, and, during pregnancy, by the placenta.[130] In the testes, testosterone is produced by the Leydig cells.[131] The male generative glands also contain Sertoli cells, which require testosterone for spermatogenesis. Like most hormones, testosterone is supplied to target tissues in the blood where much of it is transported bound to a specific plasma protein, sex hormone-binding globulin (SHBG).

A number of research groups have tried to further define the relationship of testosterone and body composition by artificial alteration of testosterone levels in eugonadal populations. Induction of a hypogonadal state in healthy men (Mauras et al 1998) or men with prostate cancer (Smith et al 2001) using a gonadotrophin-releasing-hormone (GnRH) analogue was shown to produce increases in fat mass and decreased fat free mass. Another experimental approach in healthy men featured suppression of endogenous testosterone production with a GnRH analogue, followed by treatment with different doses of weekly intramuscular testosterone esters for 20 weeks. Initially the experiments involved men aged 18–35 years (Bhasin et al 2001) but subsequently the study was repeated with a similar protocol in men aged 60–75 years (Bhasin et al 2005). The different doses given were shown to produce a range of serum concentrations from subphysiological to supraphysiological (Bhasin et al 2001). A given testosterone dose produced higher serum concentrations of testosterone in the older age group (Bhasin et al 2005). Subphysiological dosing of testosterone produced a gain in fat mass and loss of fat free mass during the study. There were sequential decreases in fat mass and increases in fat free mass with each increase of testosterone dose. These changes in body composition were seen in physiological and supraphysiological treatment doses. The trend was similar in younger versus older men but the gain of fat mass at the lowest testosterone dose was less prominent in older patients (Bhasin et al 2001; Bhasin et al 2005). With regard to muscle function, the investigators showed dose dependent increases in leg strength and power with testosterone treatment in young and older men but there was no improvement in fatigability (Storer et al 2003; Bhasin et al 2005).
There are several supplements on the market claiming to be natural testosterone boosters. I get these sorts of things in the mail all time. The companies that produce these products claim that the herbs (typically stinging nettle and tribulus) in their pills increase free testosterone by reducing SHBG. They also throw in some B vitamins for “increased energy and vitality.”
Smoking doesn’t promote maintaining male hormone levels healthy. The study has shown that smoking deprives the body from zinc. Zinc deficiency is dangerous for men because it is fraught with testosterone deficiency. The matter is that zinc is a kind of structural material for building the testosterone molecules. So, smoking combined with unhealthy diet strikes a blow against normal testosterone production.
The maximum hormone concentration in the blood is reported immediately after the workout. And the effect lasts throughout the day. However, it’s important to ensure that your physical activity is moderate. The matter is that too much high-intensity exercise can give an undesirable result. But even if for any reason you can’t attend a gym, it’s not a problem. Just move as much as possible during the day. Even simple walking will be of great benefit.

Now, many men bypass the natty test booster category altogether, head straight for designer anabolic steroids, and start injecting testosterone (among other things). And, while exogenous testosterone administration will always trump the effects of natural testosterone boosters, that instant gratification does not come without a long, dreadful list of unwanted consequences.


If you have low testosterone, your functional medicine or anti-aging physician will help you diagnose it. There are several different hormones your physician should measure, but the most important two are your free testosterone and estrogen levels, because converting too much testosterone to estrogen is a problem that’s different from not making enough testosterone in the first place. In my case, I wasn’t making very much testosterone, and what I was making my body converted to estrogen way too effectively.

A study in the European Journal of Clinical Nutrition that showed drops in cholesterol levels also highlighted the benefits of Fenugreek in controlling glucose levels (this is in fact what the trial was intended to test). When you eat, your glucose levels spike. Fenugreek helps stimulate insulin release to slow down the absorption of sugars in your intestinal tract. Fenugreek might help control blood sugar levels in diabetics.  Furthermore, high glucose levels create a poor environment for testosterone production.  This is why Tim Ferris, in his testosterone diet, advises against consuming sweets and simple starches when you are trying to increase T levels.

The mechanism of age related decreases in serum testosterone levels has also been the subject of investigation. Metabolic clearance declines with age but this effect is less pronounced than a reduction in testosterone production, so the overall effect is to reduce serum testosterone levels. Gonadotrophin levels rise during aging (Feldman et al 2002) and testicular secretory responses to recombinant human chorionic gonadotrophin (hCG) are reduced (Mulligan et al 1999, 2001). This implies that the reduced production may be caused by primary testicular failure but in fact these changes are not adequate to fully explain the fall in testosterone levels. There are changes in the lutenising hormone (LH) production which consist of decreased LH pulse frequency and amplitude, (Veldhuis et al 1992; Pincus et al 1997) although pituitary production of LH in response to pharmacological stimulation with exogenous GnRH analogues is preserved (Mulligan et al 1999). It therefore seems likely that there are changes in endogenous production of GnRH which underlie the changes in LH secretion and have a role in the age related decline in testosterone. Thus the decreases in testosterone levels with aging seem to reflect changes at all levels of the hypothalamic-pituitary-testicular axis. With advancing age there is also a reduction in androgen receptor concentration in some target tissues and this may contribute to the clinical syndrome of LOH (Ono et al 1988; Gallon et al 1989).
Ten healthy men aged around 24 years old spent 1 week sleeping for 8 hours per night at home, they then spent the next 11 nights in a lab. They slept for 10 hours per night for 3 nights, followed by 8 nights of restricted sleep, when they slept for only 5 hours. Doctors checked their blood every 15 to 30 minutes during the last night that they slept 10 hours, as well as on the sleep-restricted session.
Why bother with such common micronutrients? Because it's not uncommon for athletes to suffer from zinc and magnesium deficiencies, partly due to inadequate replenishing of levels after intense bouts of exercise. Deficiencies in these key minerals can lead to a poor anabolic hormone profile, impaired immune function, and increased cortisol, ultimately leading to decreases in strength and performance.[6]
Results from the clinical trial demonstrated that there were significant increases in hemoglobin in both men with unexplained anemia as well as men with anemia from known causes who used the testosterone gel. These results may be of clinical value, and testosterone treatment could be used to boost hemoglobin levels in men more than 65 who have unexplained anemia and low testosterone. However, more research needs to be done.

Testosterone boosters are used by many athletes worldwide to achieve a significant muscle mass increase within a short period of time.[1] However; one cannot be completely confident in terms of the quality and efficacy of such products because of several reasons, such as the possibility of bad storage conditions and originating from an unreliable source. Over the years, some consumers of testosterone boosters have complained of kidney and liver abnormalities that could be linked to their use of boosters.[10] Cases of erroneous product administration have occurred in the past as athletes may not follow the instructions on the label fully, which can lead to many side effects.[11] In the present case, a man was admitted to a hospital because of a severe abdominal pain. The pain was later found to be caused by liver injury. The diagnosis confirmed that the levels of the key hepatic enzymes were markedly elevated. The medical complications observed were found to have occurred following the consumption of two courses of a commercial testosterone booster. According to researchers based in the US, about 13% of the annual cases of acute liver failure are attributable to idiosyncratic drug- and/or supplement-induced liver injury.[12] Marked increase in the levels of ALT, AST, and gamma-glutamyl transferase was observed after consuming the first course of the commercial testosterone booster, and they started to decline after the 2nd and 3rd course. This abruptly increases the levels of liver enzymes after the first course may be attributed to the interruption effect of commercial testosterone booster on liver function as a result of the effects of its ingredients.

In many of the studies we found, those who saw the most improvement in health, testosterone, or muscle gain were those with existing nutrient or vitamin deficiencies. This means that some gains may be due more to dietary changes and generally restoring nutrient and vitamin levels than any one magic ingredient, but also that making sure your diet includes healthy amounts of nutrients should be your first step.
I am still on T therapy. But here’s what pisses me off: No one tells you that you will be hooked on the drug virtually forever! Don’t ever stop it abruptly! I did and I had a major crash: physically and emotionally. I went into the darkest depression ever…and I was lacking in energy so much that I had to have 4 naps a day…just to get through the day. I was also robbed of any initiative to do anything.
• In a trial of men with anemia, 58% percent were no longer anemic after a year of therapy, compared to 22% who received a placebo. In addition, testosterone therapy was associated with higher hemoglobin levels. Hemoglobin is a protein in the blood that carries oxygen from the lungs to other areas of the body. It also brings carbon dioxide back to the lungs.
Mínguez-Alarcón, L., Chavarro, J. E., Mendiola, J., Roca, M., Tanrikut, C., Vioque, J., ... Torres-Cantero, A. M. (2017, March–April). Fatty acid intake in relation to reproductive hormones and testicular volume among young healthy men [Abstract]. Asian Journal of Andrology, 19(2), 184–190. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/27834316
A study out of the University of Mary Hardin-Baylor in Belton, Texas, examined the effects of fenugreek supplementation on strength and body composition in resistance-trained men. Researchers found that while both the placebo and fenugreek groups significantly increased their strength during the first four weeks, only the fenugreek group saw significant increases in strength after eight weeks of training and supplementation.[5]
The medical conditions that cause excess testosterone are rare, argues Drincic. "Many people mistake the symptoms of anabolic steroid abuse with symptoms of high testosterone,” he says. Anabolic steroids, which are sometimes abused by athletes and body builders, are synthetic versions of the male hormone testosterone. They can cause behavior and mood changes that include rage, paranoia, irritability, and poor judgment.
Also, due to the intake of these synthetic substances, men start behaving in a very excited way, as well as demonstrate high levels of aggression and even violence. So, the men’s behavior may be antisocial. In addition, the men will experience breast enlargement and testicular shrinkage. The other adverse effects include hypertension, tumor growth, heart attacks and strokes, as well as development of liver disorders. It’s obvious that the numerous dangers of steroid use far outweigh a few benefits which they bring.
But if somebody fails testosterone therapy, meaning that their erections aren’t any better, I’ve said, “Well, let’s stop the testosterone and try one of the PDE5, or phosphodiesterase type 5, inhibitors — sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra).” A lot of patients then say, “Well, actually, I’d like to stay on the testosterone. True, it’s not helping my erections, but I’m more turned on, and I’m getting these other benefits.” So we often continue the testosterone and add a PDE5 inhibitor.

Testoshred stands out as a muscle hardening testosterone booster as it first combines 3 clinically studied and effective testosterone boosting agents with the powerful estrogen reducer Arimistane. The addition of Arimistane helps to prevent the conversion of testosterone to estrogen resulting in higher testosterone levels, while increasing muscle hardness and reducing body fat.


In addition to its role as a natural hormone, testosterone is used as a medication, for instance in the treatment of low testosterone levels in men and breast cancer in women.[10] Since testosterone levels decrease as men age, testosterone is sometimes used in older men to counteract this deficiency. It is also used illicitly to enhance physique and performance, for instance in athletes.
Great product. I'm a 41 yearold and found myself with low energy constantly. Since taking these pills I'm more energized and don't get home from work and just sit around the house anymore. Bonus the wife has been loving the extra benefit that they are giving us. I never thought I had a problem in that area but since I started taking these I've noticed a way longer lasting performance time.

Ten healthy men aged around 24 years old spent 1 week sleeping for 8 hours per night at home, they then spent the next 11 nights in a lab. They slept for 10 hours per night for 3 nights, followed by 8 nights of restricted sleep, when they slept for only 5 hours. Doctors checked their blood every 15 to 30 minutes during the last night that they slept 10 hours, as well as on the sleep-restricted session.
Also, due to the intake of these synthetic substances, men start behaving in a very excited way, as well as demonstrate high levels of aggression and even violence. So, the men’s behavior may be antisocial. In addition, the men will experience breast enlargement and testicular shrinkage. The other adverse effects include hypertension, tumor growth, heart attacks and strokes, as well as development of liver disorders. It’s obvious that the numerous dangers of steroid use far outweigh a few benefits which they bring.

Beast Sports Nutrition - Super Test has all four of our dream ingredients: magnesium, fenugreek, longjack, and zinc. These ingredients have all been demonstrated to help increase natural testosterone levels, with plenty of scientific research to support them (done on humans too, and not just rats). By combining all four ingredients, Super Test has the best chance of helping to increase your testosterone levels, and thereby helping you gain muscle or have a more active sex life.
I have been on TRT for over 8 years now. I feel GREAT! I read all these studies, hear in the news, and see all these dumb lawsuit commercials about testosterone causing cardiovascular events, blood clots and many other things. If anyone takes the time to do the due diligence and read the studies the picture becomes very clear. Unless you monitor all the other hormones, specifically, Estradiol, DHT, Pregenolone, Total Testosterone, Free Direct Testosterone, and DHEAS you are playing a deadly game. The reason is you must give something to control the pathways of T conversion into estradiol and or DHT. The vast majority of the studies used nothing to control those pathways and they gave men way, way more T than they needed to start with. They also gave forms of T that are not acceptable. Especially the oral version.
Hi.i have a simple question…I AM 60 YEARS OLD and my free testosterone is 7… and my regular testosterone is 700+…I really need TRT …and in case yes i need it the doctor said if i start i need to do it for the rest of my life !!! he said is not coming back!!! ..i don’t know is true or not??? With my testosterone levels i need or not to do TRT???..i am going in gym daily and i feel good in general …all my blood results are perfect …///Again if i take the TRT will help me in general ??or is better to not use the “TRT”..Thank you for your time to answer HONEST for my question ..I ask this because i don’t know what to do ..i don’t want to do something wrong???…!!!..ps .if is possible to answer me on my email ..Thank you v v much and GOD BLESS YOU …Chris…R…
When I first started TRT, my physician prescribed a cream that you rub into your skin. The cream version of TRT is not too convenient, because if someone touches you while you have the cream on, the testosterone can rub off on him/her. This can be really bad around kids or pregnant women. If you’re sleeping next to someone, the cream can get on the sheets and transfer over that way, too. The cream can be annoying, but it works. There’s also a gel version called AndroGel; I skipped it because it doesn’t absorb as well as the cream does.
In order to discuss the biochemical diagnosis of hypogonadism it is necessary to outline the usual carriage of testosterone in the blood. Total serum testosterone consists of free testosterone (2%–3%), testosterone bound to sex hormone binding globulin (SHBG) (45%) and testosterone bound to other proteins (mainly albumin −50%) (Dunn et al 1981). Testosterone binds only loosely to albumin and so this testosterone as well as free testosterone is available to tissues and is termed bioavailable testosterone. Testosterone bound to SHBG is tightly bound and is biologically inactive. Bioavailable and free testosterone are known to correlate better than total testosterone with clinical sequelae of androgenization such as bone mineral density and muscle strength (Khosla et al 1998; Roy et al 2002). There is diurnal variation in serum testosterone levels with peak levels seen in the morning following sleep, which can be maintained into the seventh decade (Diver et al 2003). Samples should always be taken in the morning before 11 am to allow for standardization.
A recent study compared total and bioavailable testosterone levels with inflammatory cytokines in men aged 65 and over. There was an inverse correlation with the pro-inflammatory soluble interleukin-6 receptor, but no association with interleukin-6 (IL-6), highly sensitive CRP (hsCRP), tumor necrosis factor-α (TNF-α) or interleukin-1β (IL-1β (Maggio et al 2006). Another trial found that young men with idiopathic hypogonadotrophic hypogonadism had higher levels of proinflammatory factors interleukin-2 (IL-2), interleukin-4 (IL-4), complement C3c and total immunoglobulin in comparison to controls (Yesilova et al 2000). Testosterone treatment in a group of hypogonadal men, mostly with known coronary artery disease, induced anti-inflammatory changes in the cytokine profile of reduced IL-1β and TNF-α and increased IL-10 (Malkin, Pugh, Jones et al 2004).

For years, the recommendation has been to get a testosterone value early in the morning because levels start to drop after 10 or 11 a.m. But the data behind that recommendation were drawn from healthy young men. Two recent studies showed little change in blood testosterone levels in men 40 and older over the course of the day. One reported no change in average testosterone until after 2 p.m. Between 2 and 6 p.m., it went down by 13%, a modest amount, and probably not enough to influence diagnosis. Most guidelines still say it’s important to do the test in the morning, but for men 40 and above, it probably doesn’t matter much, as long as they get their blood drawn before 5 or 6 p.m.
The maximum hormone concentration in the blood is reported immediately after the workout. And the effect lasts throughout the day. However, it’s important to ensure that your physical activity is moderate. The matter is that too much high-intensity exercise can give an undesirable result. But even if for any reason you can’t attend a gym, it’s not a problem. Just move as much as possible during the day. Even simple walking will be of great benefit.
More can be learned from a large, randomized, placebo-controlled trial of finasteride treatment in 18,800 men aged 55 or more. Finasteride is a 5α-reductase inhibitor which acts to prevent the metabolism of testosterone to dihydrotestosterone (DHT) – the most active androgen in the prostate. The trial showed a greater overall incidence of prostate cancer in the control group, but men treated with finasteride were more likely to have high grade tumors (Thompson et al 2003), suggesting that reduced androgen exposure of the prostate may delay the presentation of prostate cancer and/or promote advanced disease in some other way.
14. Volek JS, Volk BM, Gómez AL, Kunces LJ, Kupchak BR, Freidenreich DJ, Aristizabal JC, Saenz C, Dunn-Lewis C, Ballard KD, Quann EE, Kawiecki DL, Flanagan SD, Comstock BA, Fragala MS, Earp JE, Fernandez ML, Bruno RS, Ptolemy AS, Kellogg MD, Maresh CM, Kraemer WJ. Whey protein supplementation during resistance training augments lean body mass. J Am Coll Nutr. 2013;32(2):122-35. PMID: 24015719
Consuming high amounts of sugary foods raises your blood glucose levels, which causes your body to release insulin as a response to the raised blood glucose levels. If not managed correctly, the body begins to develop a tolerance to insulin and cannot absorb the sugars in the blood stream as it used to, causing you to become insulin resistant. Being insulin resistant releases cortisol, and as you know, cortisol has extremely negative effects, lowering testosterone by quite a bit.
After years of low libido,ED and just general lack of energy I found a urogist will to look at my symptoms. Turned out my testosterone level was 135 so I started on testosterone. Had a great improvement on everything I was having issues plus just a lot happier. My Dr. did PSA every 6 months and my PSA over almost 2 years went from 1.16 to 1.67, still pretty low for 56YOA He wanted to do a biopsy and he found 1 out of 12 cores 60%, GS3X3. I had an MRI and found a .5cm cancer, clean margins, perfectly round and dead center of the prostate.I’m doing active surviellance and the DR wants to start me on Finasteride and continue TRT. I like to believe that the years of low testosterone help the cancer to develope and the twice yearly testing of PSA by the doctor because of therapy caught it very early.I’m not too sure about TRT and Finasteride together.
“The Andro 400 has been a plus to my daily requirements of energy, stamina and weight loss. I have seen a noticeable reduction in my waistline from a 40" waist to a 37" waist. I am 6'6" and weighed 252, I now weigh 238 and feel much better. Without too much information, my sex drive and performance has been positively enhanced with greater sensitivity and stamina during those intimate times with my wife. Greater sensation, pleasure and results are evident.”
Glad to be heard. I have been using 10 times the recommended prescription dose of injectable test over the course of 6 years. Yes, 10 times the recommended dose. I use 250 at the lowest and 1000 mgs a week and sometimes 1200 mgs weekly. I am 50 years old. I look better than 90% of the 25 year olds I see in the gym. I have had zero issues. Acne a little , testicle shrinkage maybe 15%. No big deal. My sex drive is on fire. I bench pressed 340 pound today. I weigh 195 pounds and lean and muscles defined and hard as a rock. Doctors in the USA have no clue what they are doing. They read literature and have no experience or facts about test. They prescribe 50 mgs a week. Way short of what we as men need. Everyone is different, but 250mgs weekly is what we need typically. Injectable is the way to go. Gels are a weak joke. My doctor basically told me he was scared to prescribe more than 50 mgs weekly for fear of being sued if something went wrong. I found my own source and have been on top of the world for 6 years. Father died of prostate cancer. Mine prostate is fine. Prostate cancer from test is another example of ignorance in medical field. I am living proof that one can inject 10 times the recommended rate for the better part of a decade with no probs. I do hope the medical field catches up with the times and stops relying on archaic info.
Testosterone is well known as the most critical anabolic, not to mention androgenic, hormone in the body. It’s what separates the men from the boys. Healthy testosterone levels are critical for guys who want to build muscle mass, boost strength, and drop body fat. Testosterone also supports sexual health and gives a competitive edge. It’s truly the alpha hormone.

By passing this bill, the Congress has amended the Controlled Substances Act to include Androstenedione supplements such as 4 Androstenediol, 5 Androstenediol, etc. The original Anabolic Steroid Control Act was passed in 1990 creating a list of anabolic steroids that would be classified as "Schedule III" substances and put in the same category as drugs such as heroin and cocaine. Now, with the passage of Senate Bill 2195 (the Anabolic Steroid Control Act of 2004), they have added Androstenedione supplements to the Controlled Substances Act.


I am 35 and had the non sexual symptoms for awhile now( weight gain/muscle loss, extreme fatigue, lack of clarity/concentration) I got my testosterone levels checked last week and it was 35.4 ng. Not a typo, 35.4. I was told by my dr. That I needed to start TRT right away as low t can effect a lot different things in your body. I did my first injection last night (200mg/ml every 2 weeks) about 8 pm and td now 3:30 am and I’m wide awake and feel extremely motivated to go to the gym and work out. I know each person is different but should I feel like this already, or is it a placebo effect at this point?
Pellets. Your doctor will place the testosterone pellets under the skin of your upper hip or buttocks. Your doctor will give a shot of local anesthesia to numb your skin, then make a small cut and place the pellets inside the fatty tissues underneath your skin. This medication dissolves slowly and is released over about 3-6 months, depending on the number of pellets. 
55+ million men in america between 40 and 70 years of age is a large enough group to warrant interest in a thorough study of the aged male delivery system and other sex related issues. There is a good chance there are 55 million women out there wishing for some kind of help also. Those are significant numbers, about 1/3 of the total population and the lions share of the income producers. And the best the medical community can do is speculate at the real cause for a significant cancer? Perhaps prostate cancer is the real cause of global warming, there is no real science unless there is a real paycheck?

Ashwagandha is sometimes included in testosterone supplements because of the hypothesis that it improves fertility. However, we couldn’t find sufficient evidence to support this claim (at best, one study found that ashwagandha might improve cardiorespiratory endurance). WebMD advocates caution when taking this herb, as it may interact with immunosuppressants, sedative medications, and thyroid hormone medications.
The unsexy truth is that increasing T naturally simply comes down to making some long-term changes in your diet and lifestyle. As you’ll see, what I did to increase T largely boils down to eating better, exercising smarter, and getting more sleep. That’s pretty much it. But as with most things in life, the devil is in the details, so I’ll share with you exactly what I did and provide research that explains why the things I did helped boost my testosterone.
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Side note, insurance rarely will cover it and cause a long paper trail to even approve it which is unfortunate and disheartening. Especially when it is done out of network. Currently I have found a place to supply all of the aboue sent to my house at approximately $200.00 per month. Still an unfortunate cost for a medical reason that the insurance companies don’t approve. Best of luck to all of you.
Zinc deficiency also negatively affects testosterone levels, according a 2014 article in the Journal of Plant Biochemistry and Physiology. The authors of this review note that zinc supplementation can increase circulating testosterone in some populations. In fact, daily supplementation with typical doses may double testosterone within a few months.

Stored food in glassware and never, ever, ever heated food in plastic containers. Most modern plastics contain phthalates. Phthalates are what give plastic their flexibility, durability, and longevity. But they also screw with hormones by imitating estrogen. Because I didn’t want any of those T-draining molecules in my food, I kept all my food in glassware. I also made sure to never heat food in plastic containers, as heat increases the transfer of phthalates into food.

A large number of trials have demonstrated a positive effect of testosterone treatment on bone mineral density (Katznelson et al 1996; Behre et al 1997; Leifke et al 1998; Snyder et al 2000; Zacharin et al 2003; Wang, Cunningham et al 2004; Aminorroaya et al 2005; Benito et al 2005) and bone architecture (Benito et al 2005). These effects are often more impressive in longer trials, which have shown that adequate replacement will lead to near normal bone density but that the full effects may take two years or more (Snyder et al 2000; Wang, Cunningham et al 2004; Aminorroaya et al 2005). Three randomized placebo-controlled trials of testosterone treatment in aging males have been conducted (Snyder et al 1999; Kenny et al 2001; Amory et al 2004). One of these studies concerned men with a mean age of 71 years with two serum testosterone levels less than 12.1nmol/l. After 36 months of intramuscular testosterone treatment or placebo, there were significant increases in vertebral and hip bone mineral density. In this study, there was also a significant decrease in the bone resorption marker urinary deoxypyridinoline with testosterone treatment (Amory et al 2004). The second study contained men with low bioavailable testosterone levels and an average age of 76 years. Testosterone treatment in the form of transdermal patches was given for 1 year. During this trial there was a significant preservation of hip bone mineral density with testosterone treatment but testosterone had no effect on bone mineral density at other sites including the vertebrae. There were no significant alterations in bone turnover markers during testosterone treatment (Kenny et al 2001). The remaining study contained men of average age 73 years. Men were eligible for the study if their serum total testosterone levels were less than 16.5 nmol/L, meaning that the study contained men who would usually be considered eugonadal. The beneficial effects of testosterone on bone density were confined to the men who had lower serum testosterone levels at baseline and were seen only in the vertebrae. There were no significant changes in bone turnover markers. Testosterone in the trial was given via scrotal patches for a 36 month duration (Snyder et al 1999). A recent meta-analysis of the effects on bone density of testosterone treatment in men included data from these studies and two other randomized controlled trials. The findings were that testosterone produces a significant increase of 2.7% in the bone mineral density at the lumber spine but no overall change at the hip (Isidori et al 2005). These results from randomized controlled trials in aging men show much smaller benefits of testosterone treatment on bone density than have been seen in other trials. This could be due to the trials including patients who are not hypogonadal and being too short to allow for the maximal effects of testosterone. The meta-analysis also assessed the data concerning changes of bone formation and resorption markers during testosterone treatment. There was a significant decrease in bone resorption markers but no change in markers of bone formation suggesting that reduction of bone resorption may be the primary mode of action of testosterone in improving bone density (Isidori et al 2005).
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