It could be said that testosterone is what makes men, men. It gives them their characteristic deep voices, large muscles, and facial and body hair, distinguishing them from women. It stimulates the growth of the genitals at puberty, plays a role in sperm production, fuels libido, and contributes to normal erections. It also fosters the production of red blood cells, boosts mood, and aids cognition.
According to a study in the International Journal of Reproductive BioMedicine, D-Aspartic acid increases testosterone levels in some animals. However, studies that have looked at its effects on humans are inconclusive and mainly of poor quality. The paper says there is an urgent need for more research on this chemical, which occurs naturally in some human tissues.

That said, a group of researchers at the National University of Malaysia did a systemic literature review of longjack, looking for clinical research that demonstrated a relationship between the shrub and testosterone levels. Of 150 articles, only 11 met their inclusion criteria — involving humans and scientifically rigorous. However, of those 11 studies, seven “revealed remarkable association” between using longjack and improving male sexual health, while the remaining four “failed to demonstrate sufficient effects.” The team concluded that longjack looks “promising” when it comes to raising low testosterone, and that there is convincing evidence that it works.
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.

Testosterone may increase competitiveness. Men are known to be a competitive bunch and testosterone is likely responsible for our drive to win. Testosterone is linked with a man’s desire for power and status (Dabbs & Dabbs 2000). Testosterone ramps up before a fight or competition – producing effects on muscle mass and hemoglobin, quickening reactions, improving visual acuity, and increasing your feelings of endurance and indomitability. It also increases your “gameness:” One study showed that a man’s testosterone level after losing a game predicted whether or not he got back in for another round. Men who experienced a severe drop were less likely to play again, while men who experienced little or no drop in T levels got back into the game. Researchers concluded from this observation that T is one of the factors driving competitiveness in men.
Joe Costello is a Nutrition & Wellness Consultant, certified by the American Fitness Professionals & Associates (AFPA), author, and internet blogger. Joe has more than 9 years of experience in the sports nutrition industry and over 3 years of experience as a supplement and nutrition blogger. As a certified NWC who specializes in dietary supplements, Joe strives to deliver accurate, comprehensive, and research-backed information to his readers. You can find more of Joe’s work including his E-Books about fitness and nutrition at his official website joecostellonwc.com, or connect with him on LinkedIn, Facebook, Instagram, Vimeo, or YouTube.

We should probably start with the elephant in the room: do these supplements increase testosterone? The answer is probably yes. There are some ingredients that help convince your body to produce more testosterone, but there’s a catch. Testosterone boosters aren’t actually great at boosting; that is, at pushing your testosterone levels above your healthy, normal balance. Boosters typically act more like restorers — helping bring low testosterone levels back to that healthy equilibrium rather than boosting you above normal testosterone levels. Just like how if you have anemia, taking a vitamin B12 supplement can help restore your energy and reduce fatigue, but if your B12 levels are good, a supplement won’t give you super energy levels to stay awake for three days — your body will likely just process (read: pee) out the extra.
This is one of the most controversial recommendations I make, but it shouldn’t be. It’s no different than using thyroid medication. If your levels are low, and the other techniques here don’t work, use TRT. You will like your life again. If your levels are low, bioidentical testosterone will make you live longer and better, provided you use it right.
Men who start using the gels have to come back in to have their testosterone levels measured again to make sure they’re absorbing the right amount. Our target is the mid to upper range of normal, which usually means around 500 to 600 ng/dl. The concentration of testosterone in the blood actually goes up quite quickly, within a few doses. I usually measure it after two weeks, though symptoms may not change for a month or two.
FITNESS DISCLAIMER: The information contained in this site is for educational purposes only. Vigorous high-intensity exercise is not safe or suitable for everyone. You should consult a physician before beginning a new diet or exercise program and discontinue exercise immediately and consult your physician if you experience pain, dizziness, or discomfort. The results, if any, from the exercises may vary from person-to-person. Engaging in any exercise or fitness program involves the risk of injury. Mercola.com or our panel of fitness experts shall not be liable for any claims for injuries or damages resulting from or connected with the use of this site. Specific questions about your fitness condition cannot be answered without first establishing a trainer-client relationship.
According to a study in the International Journal of Reproductive BioMedicine, D-Aspartic acid increases testosterone levels in some animals. However, studies that have looked at its effects on humans are inconclusive and mainly of poor quality. The paper says there is an urgent need for more research on this chemical, which occurs naturally in some human tissues.

Disclaimer. We do not claim that we have got the approval from Food and Drug Administration when offering our products and services on this website. We do not try to position the testosterone booster supplements the information on which we give on this website as the professional treatment alternative. Also, we do not appeal to the users to practice self-treatment by using the content here. We only publish the content that the authors provide to us. Therefore, these articles may not express our opinion, only the opinion of the article writers. In addition, take into consideration that the content writers are not the healthcare practitioners. Hence, it follows that the writers’ opinions should not be perceived as medical advice. We emphasize that the diet pills intake should be a decision taken based on the recommendations of the real healthcare practitioner since only the doctor can make a diagnosis and prescribe any treatment. We cooperate with the affiliated websites which can publish their content on this website for advertising purposes. Consequently, we do not have any bearing upon trademarks, service marks, logos, and brand names that come from the affiliated websites. Moreover, the content provided by the advertising partners is subject to amendments and deletion at the content owners’ own discretion.


“Poor lifestyle can mimic the symptoms of low testosterone and can actually cause low testosterone as well,” says Hodzovic. “The main culprits include lack of sleep, excessive stress, too little or too much exercise and too little or too much body fat. Getting healthy and active and eating a balanced nutritious diet along with enough sleep are the most important things to do.

How do you boost testosterone naturally? Testosterone is a male sex hormone. Low levels can cause changes to the distribution of body fat and muscle strength. Testosterone reduces with age, but people can boost it with lifestyle changes, including diet and exercise. Adequate sleep, nutritional supplements, and stress reduction may also help. Learn more here. Read now

As a nurse I am very concerned with following my labs as most of these places don’t actually follow my labs. I also happen to have the side effect of polycythemia and donate 2-3 times a year for this reason. At one point I asked my doctor who referred me to a urologist. At the time I was on 150mg IM with half a dose or 0.5mL twice weekly to avoid the “roller coaster”. Anyways, I went there so I could get some concrete answers as to why I was having low T, this doctor all but threw me out of his office stating that “they” are making me dependent on T. As a professional in the medical field I was highly offended, he didn’t even speak with me about anything at all, I had no chance to ask what was going on, if my dosing was correct or if there was anything else I needed to do. He kicked me out and said he wasn’t even charging for the visit. Absolutely applaud. So to those who have found a Dr. that actually listens and works with your individual issues, kuddos. To the rest of us I highly recommend that you research as much as possible before using out of state clinics.
One study showed that six months of zinc supplementation among slightly zinc-deficient elderly men doubled serum levels of testosterone. And another eight-week trial found that college football players who took a nightly zinc supplement showed increased T-levels and increased leg strength that was 250 percent greater than a placebo! Holy quads, Batman! Research has also shown deficiencies in zinc to be a risk factor for infertility caused by low testosterone levels.

We required all of our testosterone boosters to have magnesium, but gave preference to magnesium aspartate, citrate, lactate, and chloride. These forms have been found to be more easily absorbed than magnesium oxide and sulfate. (On the other hand, it didn’t count if the supplement had magnesium stearate, which is used to make pills not stick together.)


And remember, saturated fats work best (along with monounsaturated fats – olive oil, almonds, avocados etc.). In fact higher intakes of polyunsaturated fats (canola oil, sunflower oil, soybean oil, safflower oil, margarine etc.) are linked to LOWER testosterone levels (14 & 15). I explore the dangers of PUFA's in a lot more detail in this article - PUFA's: The Worst Thing For Your Health That You Eat Everyday.
How alpha are you? Well, how many shakes of hot sauce can you handle? A recent study from France found men who have a taste for spicy foods tend to have higher testosterone levels than those who can’t handle the heat. Of the 114 male participants surveyed, researchers saw a clear correlation between frequent hot-sauce usage and higher T-levels. Study authors suggest the findings may be due in part to capsaicin—the fiery compound in chili pepper that previous studies have associated with increased testosterone levels. In animal studies, capsaicin has also shown to increase the size of sex organs, while simultaneously decreasing belly fatbelly fat. Yowza!

We’ll be honest. Testosterone boosters don’t really boost. The best testosterone booster is like taking a multivitamin with extra herbs that might slightly and temporarily increase your testosterone levels. Like all supplements, finding the right testosterone booster means wading into a sea of ingredients, all promising to help. Of 133 testosterone boosters, we found only one with the right ingredients to help raise your testosterone levels: Beast Sports Nutrition - Super Test ($45.88 for 180 capsules, or $2.04 per day).

Get some sun – I know many people say you should avoid the sun like a vampire unless you want to get skin cancer but we actually do need some sunlight. This is because the sun is the best source of vitamin D which plays a huge role in testosterone production and other bodily functions. Keep your sun exposure in moderation but do not avoid it altogether.
Japanese Knotweed (a.k.a Hu Zhang or Polygonum cuspidatum) is highlighted by WebMD as needing more evidence to rate its effectiveness in a number of different areas: like treating constipation and liver or heart disease. They also warn that it can interact poorly with medications that are changed and broken down by the liver, and those that slow blood clotting (anticoagulants and antiplatelets).
In addition, the gel forms of testosterone, applied under your arm or on your upper arm and shoulder, can be transferred to others if you don’t wash the area after applying it. Children exposed to the hormone have experienced enlargement of the penis or clitoris, growth of pubic hair, increased libido, and aggressive behavior. Women can experience acne and the growth of body hair and, if they are pregnant or breastfeeding, can transfer the hormone to their babies.
Some studies have looked at testosterone therapy and cognition. Although the findings weren’t definitive, there was some evidence of cognitive improvement. Other studies have shown that it improves mood. Testosterone therapy has also been shown to be effective in the treatment of osteoporosis and in increasing muscle bulk and strength. [See “Testosterone’s impact on brain, bone, and muscle,” above.]
Looking for ingredients that work in the realm of supplements can be like finding a needle in a haystack. Testosterone boosters, like all dietary supplements, are not approved by the Food and Drug Administration prior to marketing. This lack of oversight dates back to the 1994 Dietary Supplement Health and Education Act (DSHEA), which stipulated that purveyors of supplements weren’t required to prove the safety of their products or the veracity of what’s on the labels to the FDA before listing them for sale. Often, there isn’t a lot of scientific backing behind an ingredient, or research has been done solely on animals, not humans.

In addition to weightlifting, studies have shown that HIIT workouts can also help boost testosterone levels. For those of you who don’t know, HIIT stands for high-intensity interval training. It calls for short, intense bursts of exercise, followed by a less-intense recovery period. You repeat with the intense/less-intense cycle several times throughout the workout. In addition to increasing T, HIIT has been shown to improve athletic conditioning and fat metabolism, as well as increase muscle strength.
Camacho EM1, Huhtaniemi IT, O'Neill TW, Finn JD, Pye SR, Lee DM, Tajar A, Bartfai G, Boonen S, Casanueva FF, Forti G, Giwercman A, Han TS, Kula K, Keevil B, Lean ME, Pendleton N, Punab M, Vanderschueren D, Wu FC; EMAS Group. “Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study.” Eur J Endocrinol. 2013 Feb 20;168(3):445-55. doi: 10.1530/EJE-12-0890. Print 2013 Mar.
Cross-sectional studies have found a positive association between serum testosterone and some measures of cognitive ability in men (Barrett-Connor, Goodman-Gruen et al 1999; Yaffe et al 2002). Longitudinal studies have found that free testosterone levels correlate positively with future cognitive abilities and reduced rate of cognitive decline (Moffat et al 2002) and that, compared with controls, testosterone levels are reduced in men with Alzheimer’s disease at least 10 years prior to diagnosis (Moffat et al 2004). Studies of the effects of induced androgen deficiency in patients with prostate cancer have shown that profoundly lowering testosterone leads to worsening cognitive functions (Almeida et al 2004; Salminen et al 2004) and increased levels of serum amyloid (Gandy et al 2001; Almeida et al 2004), which is central to the pathogenesis of Alzheimer’s disease (Parihar and Hemnani 2004). Furthermore, testosterone reduces amyloid-induced hippocampal neurotoxity in vitro (Pike 2001) as well as exhibiting other neuroprotective effects (Pouliot et al 1996). The epidemiological and experimental data propose a potential role of testosterone in protecting cognitive function and preventing Alzheimer’s disease.
Test1fy comes in with one of the most unique formulas containing ingredients that not only support testosterone increases and lean mass gains, but also help in increasing hunger making it the perfect addition to anyone’s natural bulking stack. It is overall a well rounded and potent formula making it perfect for anyone, from newbie to the seasoned veteran.
It goes without saying that what you eat significantly influences your hormone balance and body composition. This is nothing new. There are countless athletes and bodybuilders who are paying a close attention to what they eat for a reason. For example, if you consume a lot of so-called junk food, then you inevitably end up with a poor nutritional profile. In plain English, you can forget about a six-pack and the high testosterone.
Studies have demonstrated reduced testosterone levels in men with heart failure as well as other endocrine changes (Tappler and Katz 1979; Kontoleon et al 2003). Treatment of cardiac failure with chronic mechanical circulatory support normalizes many of these changes, including testosterone levels (Noirhomme et al 1999). More recently, two double-blind randomized controlled trials of testosterone treatment for men with low or low-normal serum testosterone levels and heart failure have shown improvements in exercise capacity and symptoms (Pugh et al 2004; Malkin et al 2006). The mechanism of these benefits is currently unclear, although a study of the acute effects of buccal testosterone given to men with chronic cardiac failure under invasive monitoring showed that testosterone increased cardiac index and reduced systemic vascular resistance (Pugh et al 2003). Testosterone may prove useful in the management of cardiac failure but further research is needed.
“What on earth do you mean?” Well, I don’t literally mean taking it to the compound. What I mean to say is that you should be incorporating the three most important compound exercises into your routine: bench press, squats, and deadlifts. In case you didn’t know, by training large muscle groups your body releases more testosterone. When you do these three lifts, and perform them properly, then you’ll reap the benefits of not only muscle gains, but also that of an increased release of testosterone and growth hormone.
In my late 40’s I was on Androgel. I lost weight and gained muscle; became healthier over all, brighter outlook, more active, and a harder erection that had a mind of it’s own. Then I went on injectable testosterone. My numbers are normal but my weight is up even after eating less. As well everything else is shelter smelter. I intend to get back to Androgel. (this, of course, is my own personal study)

Whether you are currently on a plateau or you are looking to obtain more energy in life and in the gym this test booster and its full coverage blend of natural extracts is designed to support your body’s anabolic potential without compromising natural production. Test Booster 1.0 works with your body to promote elevations in natural test levels; helping to support muscle density, a balanced metabolism, and insane natural energy levels.
My energy level have increased and my muscle mass has also increased, so I have positive results. As I said before I didn’t have a problem with achieving erections or maintaining, but with these injections I am now getting quite a good deal more spontaneous erections, and then when I do get one it does feels harder and stronger. The stronger and harder aspect is great, but the more often spontaneous is a bit annoying. 🙂
For the 3rd year in a row, DAA Max claims the #1 spot in the Top 10. A product that stands out in all categories with a formula that has been shown in studies to increase free testosterone levels after just 12 days of consistent use. DAA Max’s feedback over the years has shown that this product is not only potent in terms of elevating testosterone and boosting one’s libido, but at its low price it just can’t be beaten.

At the present time, it is suggested that androgen replacement should take the form of natural testosterone. Some of the effects of testosterone are mediated after conversion to estrogen or dihydrotestosterone by the enzymes aromatase and 5a-reductase enzymes respectively. Other effects occur independently of the traditional action of testosterone via the classical androgen receptor- for example, its action as a vasodilator via a cell membrane action as described previously. It is therefore important that the androgen used to treat hypogonadism is amenable to the action of these metabolizing enzymes and can also mediate the non-androgen receptor actions of testosterone. Use of natural testosterone ensures this and reduces the chance of non-testosterone mediated adverse effects. There are now a number of testosterone preparations which can meet these recommendations and the main factor in deciding between them is patient choice.

The regular intake of testosterone boosters is known for the high level of safety comparing to the hormone injections and the use of illegal steroids. But still to protect yourself against any possible adverse reactions, you should remember that the supplementation can’t be continuous. The breaks from time to time are required. Such an approach to the use of boosters is healthy and best-working if you aspire to enhance own hormone production without any harm.
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.
It may also become a treatment for anemia, bone density and strength problems. In a 2017 study published in the journal of the American Medical Association (JAMA), testosterone treatments corrected anemia in older men with low testosterone levels better than a placebo. Another 2017 study published in JAMA found that older men with low testosterone had increased bone strength and density after treatment when compared with a placebo. 
TestoGen USA stood head and shoulders above the rest, which is why it earned the top spot on our list. This testosterone supplement will help keep men on a more even keel when it comes to both stamina and temperament. You won’t feel wiped out at the end of the day and you’ll be less likely to feel your tension levels rising as you deal with everyday annoyances. In addition, it will stimulate your libido and can even help you lose excess body fat.
Caffeine. Use caffeine moderately. Too much of the jittery juice increases cortisol, which decreases testosterone. Moreover, consuming caffeine late in the day hurts sleep, which lowers testosterone production. But one recent study indicates that caffeine consumed before working out may boost testosterone levels and help you exercise more efficiently. During my experiment I popped a piece of caffeinated gum five minutes before my workouts. Each piece had 100 mg of caffeine, about the same amount in a cup of coffee. That was usually it for my caffeine intake that day.
Ben has mentioned APOE many times, as in this podcast, with the reference in this transcript as something like 34/44. I’ve always assumed that meant a number of different genes that related to APOE having the homozygous or heterzygous mutations. I’ve only been able to find one rs in my 23andme raw data that seems meaningful to this, rs429358. How do you all figure out your APOE status? Are you getting this from one of the other companies that analyzes part of your raw data for you?
Unlike injection or ingestion of anabolic steroids, the use of testosterone boosters is relatively safe for daily consumption. In order to ward off any negative side effects, it is best to take a rest after finishing a bottle of your preferred testosterone booster. This will allow the body to relax after months of taking supplements that increase testosterone levels. This practice effectively cleans the body as well.

TT may help you but it may have adverse (harmful) results. (See discussion of these side effects below.) The Federal Drug Administration (FDA) has said that testosterone drug labels should state that there is a risk for heart disease and stroke for some men using testosterone products. All men should be checked for heart disease and stroke before, and periodically while on, TT. The AUA however, on careful review of evidence-based peer review literature, has stated that there is no strong evidence that TT either increases or decreases the risk of cardiovascular events.
Ben has mentioned APOE many times, as in this podcast, with the reference in this transcript as something like 34/44. I’ve always assumed that meant a number of different genes that related to APOE having the homozygous or heterzygous mutations. I’ve only been able to find one rs in my 23andme raw data that seems meaningful to this, rs429358. How do you all figure out your APOE status? Are you getting this from one of the other companies that analyzes part of your raw data for you?
Hello – Has anybody here had their hair fall out after significantly increasing their T level? In 90 days of Clomiphene Citrate use my Total Testosterone went from 290 to 1100. and my Free T went from 50 to 202. Yes, it went way up! CC works. I have no idea why anybody would bother with gels and shots without giving this a chance. It costs almost nothing. so cheap.
The authors reported statistically significant increases in both noncalcified and total coronary artery plaque in patients receiving testosterone treatment. Participants’ coronary artery calcium scores, another measure of calcified plaque, were not significantly affected by testosterone treatment. Although these results are potentially a cause for concern, additional studies are required to determine the clinical relevance of this increase in plaque volume.
AML Test includes each of the best natural testosterone boosters discussed above as well as red wine polyphenols which function as powerful, all-natural aromatase inhibitors that lower estrogen and increase testosterone levels. These polyphenols also boost nitric oxide production which enhances vasodilation and blood flow to all regions of the body.
This post can absolutely change your life, and probably help you avoid some pitfalls. Like shrunken balls. (I am not an expert in the synthetic anabolic testosterone drugs used by bodybuilders — they carry lots of risks but pack a big punch if you want to get swole. Bulletproof is all about having massive clean energy, looking good, and living a very long time…so anabolic steroids aren’t on my roadmap.)
High intensity exercise is crucial to boost testosterone (13).  Exercises should be explosive in nature and maximize the resistant overload on the muscles.  Large muscle group compound lifts such as squats, deadlifts & burpees are some of the best testosterone boosting exercises.  The training session should be short (5-30 mins) and have very little rest periods between sets.
Trials of testosterone treatment in men with type 2 diabetes have also taken place. A recent randomized controlled crossover trial assessed the effects of intramuscular testosterone replacement to achieve levels within the physiological range, compared with placebo injections in 24 men with diabetes, hypogonadism and a mean age of 64 years (Kapoor et al 2006). Ten of these men were insulin treated. Testosterone treatment led to a significant reduction in glycated hemoglobin (HbA1C) and fasting glucose compared to placebo. Testosterone also produced a significant reduction in insulin resistance, measured by the homeostatic model assessment (HOMA), in the fourteen non-insulin treated patients. It is not possible to measure insulin resistance in patients treated with insulin but five out of ten of these patients had a reduction of insulin dose during the study. Other significant changes during testosterone treatment in this trial were reduced total cholesterol, waist circumference and waist-hip ratio. Similarly, a placebo-controlled but non-blinded trial in 24 men with visceral obesity, diabetes, hypogonadism and mean age 57 years found that three months of oral testosterone treatment led to significant reductions in HbA1C, fasting glucose, post-prandial glucose, weight, fat mass and waist-hip ratio (Boyanov et al 2003). In contrast, an uncontrolled study of 150 mg intramuscular testosterone given to 10 patients, average age 64 years, with diabetes and hypogonadism found no significant change in diabetes control, fasting glucose or insulin levels (Corrales et al 2004). Another uncontrolled study showed no beneficial effect of testosterone treatment on insulin resistance, measured by HOMA and ‘minimal model’ of area under acute insulin response curves, in 11 patients with type 2 diabetes aged between 33 and 73 years (Lee et al 2005). Body mass index was within the normal range in this population and there was no change in waist-hip ratio or weight during testosterone treatment. Baseline testosterone levels were in the low-normal range and patients received a relatively small dose of 100 mg intramuscular testosterone every three weeks. A good increase in testosterone levels during the trial is described but it is not stated at which time during the three week cycle the testosterone levels were tested, so the lack of response could reflect an insufficient overall testosterone dose in the trial period.
AC, I just ran across the thread… definitely start the injections. Should help with levels that low. I’m 36 and have battled low T for 6-7 years. My labs came back to show 90ng/dl when I just turned 30, and I’ve done Testosterone cypionate injections @ 100mg/mL weekly, Testim, Androgel, and Fortesta over the years. I’m actually going to my endocrinologist tomorrow to have new blood work done.
Some of the effects of testosterone treatment are well recognised and it seems clear that testosterone treatment for aging hypogonadal men can be expected to increase lean body mass, decrease visceral fat mass, increase bone mineral density and decrease total cholesterol. Beneficial effects have been seen in many trials on other parameters such as glycemic control in diabetes, erectile dysfunction, cardiovascular risk factors, angina, mood and cognition. These potentially important effects require confirmation in larger clinical trials. Indeed, it is apparent that longer duration randomized controlled trials of testosterone treatment in large numbers of men are needed to confirm the effects of testosterone on many aspects of aging male health including cardiovascular health, psychiatric health, prostate cancer and functional capacity. In the absence of such studies, it is necessary to balance risk and benefit on the best available data. At the present time the data supports the treatment of hypogonadal men with testosterone to normalize testosterone levels and improve symptoms. Most men with hypogonadism do not have a contraindication to treatment, but it is important to monitor for adverse consequences including prostate complications and polycythemia.
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).
×