Hello there Abraham. My doc and you know each other well. We reside in Richmond, VA. Doc told me to inject my weekly Cypionate into sub fat for longer absorption, with reference you shared this info him with him. I have been his TRT patient for 10 years now. He is the best. I wont mention names. Please point me to a study showing the results of testosterone absorption from fat.
Take 1 teaspoon. Incredibly dense in nutrients and feed by bees to the larvae who grows on to be the queen bee. I found one human study where a 4g daily serving led to an small increase in testosterone in older men (ref 78). There are also numerous animal studies (ref 79) showing positive effects. Personally I source NZ manuka royal jelly from Manuka Health.
Such sort of injuries varies in severity and extent of damage markedly from one person to the other and withdrawal of the drug/supplement coupled with proper medical attention suffice in terms of alleviating the symptoms.[8,12] This was observed in the present case. However, the liver injury observed here may not be confidently linked to product consumption as the subject later reported that the following recovery he consumed two more courses of the booster with no side effects. Tests performed following hospital discharge, and repeated use of the product showed AST and ALT to be slightly high, whereas the rest of the blood parameters tested appeared to be normal. The AST/ALT ratio is considered to be a very important parameter for the evaluation of liver diseases, such as non-alcoholic fatty liver disease,[13] though it is rarely considered alone. Overall, the evidence was inconclusive in the present work in terms of linking the use of a testosterone booster with liver injury. However, even though a single case report cannot establish causality with statistical power.[13] Further research on the usage of a commercial testosterone booster within large populations for a long period is necessary to investigate whether the symptoms shown in the present case were significantly present in other athletes consuming the same commercial product or not. To guarantee an optimal outcome with no severe side effects, further research is warranted to confirm the present findings and determine whether the effects observed in this case report would be statistically significant in larger samples.

Low testosterone levels have a dramatic effect on emotional state. The American Academy of Family Physicians lists depression, impaired cognition and increased fatigue as symptoms of low testosterone production, or hypogonadism. Testosterone replacement therapy for hypogonadal men has successfully reduced negative moods relating to fatigue and depression while increasing feelings of self-esteem. Increasing testosterone in eugonadal men has also shown positive emotional benefits such as increased feelings of self-esteem and reduction of fatigue. The intensity of these benefits is dependent on dosage; a wide body of literature on testosterone increase has shown that at higher dosage aggression, and aggressive response, can become pronounced.

Use natural grooming products. Most grooming products these days contain parabens, another type of xenoestrogen. And by most, I mean more than 75% of all products. To reduce my exposure as much as possible, I became a hippy during my experiment and started using all natural, paraben-free grooming products. You can find most of these items at most health food stores:

Lose some weight – It goes without saying that being overweight is unhealthy for more than one reason. As your weight increases, your testosterone levels decrease inevitably. The good news is that as soon as you start losing weight, you can reverse this process and your testosterone levels will begin rising again. Could you think of a better reason to exercise regularly?
Testosterone is only one of many factors that influence aggression and the effects of previous experience and environmental stimuli have been found to correlate more strongly. A few studies indicate that the testosterone derivative estradiol (one form of estrogen) might play an important role in male aggression.[66][71][72][73] Studies have also found that testosterone facilitates aggression by modulating vasopressin receptors in the hypothalamus.[74]
The sad truth, is that these purported testosterone support products were completely and utterly useless. They did absolutely nothing for testosterone production due to the simple fact that they didn’t contain any ingredients shown in human research trials to actually support testosterone production. Sure, they included all sorts of ancient herbs and botanical extracts that worked well in rats, but nary a compound that would actually benefit a real live human being.
I can report that I saw decreased body fat during my three-month testosterone experiment. I started off with 18% body fat and ended the experiment with 12% body fat. I almost have a six-pack! This is the leanest I’ve ever been in my entire life. The funny thing is, I wasn’t even trying to shed body fat. It just happened. All hail, mighty testosterone!
When the body cannot produce enough testosterone on its own, the term is called hypogonadism.  Testosterone boosters do not give the user actual testosterone (like with steroids), rather, they kickstart the production of this very important hormone.  For that reason, it’s important to find a potent formulation that has one or multiple key ingredients in it.
After 90 days, it seemed like the Andro Gel kind of stopped having it’s effect. Went back to see the doc, and my levels had dropped back to about 198 from high 200’s. Doc said it’s not unusual that the body gets used to it, and maybe I needed to adjust up. I switched to four pumps per day, and I felt immediate effects. Now…there is a period of ultra-horniness, and sometimes, you will feel some of the “roid rage” at some of these levels. It varies from person to person. Generally, if you are an ass, or high strung, this will amplify it. If you are pretty mellow, you may notice that every once in a while you’ll get angry at something that does matter, but again, it’s different person to person.
Dr. Abraham Morgentaler, an associate professor of surgery at Harvard Medical School and the director of Men’s Health Boston, specializes in treating prostate diseases and male sexual and reproductive difficulties. He has developed particular expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment strategies he uses with his own patients, and why he thinks experts should reconsider the possible link between testosterone-replacement therapy and prostate cancer.
A side of garlic knots or onion bread can boost your sex drive … just make sure your date has a slice, too! Studies suggest a compound in the stinking rose triggers the release of luteinizing hormone, which regulates production of testosterone. One study showed supplementing with garlic as part of a high-protein diet could substantially boost testosterone levels. And a recent animal study found just 1 gram of onion per kg of body weight could boost T-levels by over 300 percent in just 20 days. Garlic and onions both contain the chemical diallyl disulfide, which stimulates the release of a hormone that spurs the production of testosterone.

I highly recommend using a great essential amino acid mix post-exercise in order to boost testosterone.  These essential amino acids and especially the concentrated branched chain amino acids leucine, isoleucine and valine stimulate muscle protein synthesis.  Getting these amino acids in the post-workout window dramatically boosts testosterone production (14).  I like using our Amino Strong and will often recommend a scoop pre-workout and post-workout for the best muscle building, testosterone boosting benefits.
If your need is greater though, there are other legal options to consider. DHEA is a precursor steroid hormone that is only available on prescription in the UK, but if taken under close supervision it can have dramatic effects. It must be taken under supervision though because too high a dose can cause mood changes and aggression — roid rage, in other words — as well as all the other unwanted by-products of too much testosterone.

Cholesterol is the building block of testosterone, and eating healthy fats, including saturated fats, helps your body make “good” cholesterol while also supporting healthy hormone balance. Give your body a dose of healthy fats and proteins by consuming moderate amounts of meats from hormone-free animals, grassfed cattle, and wild-caught fish. Nosh on healthy-fat sources such as olives, nuts, seeds, avocados, and coconut oil.

Made many mistakes growing up. Late highschool, small group of guys tried Testosterone and obviously it worked great on all levels especially on the football field etc. College years we did it again and again but not anywhere near the levels of body builders we knew and saw at the gym. When it became harder to find, then….. poof it became “legal” in the form of Pro-hormones. Great right? Not so. It worked but it also worked on everything else in a negative way. Mainly liver toxicity that I noticed and just the general idea of not really knowing what was in it. When I was 38 I had a bad event with diverticulitis. I was hospitalized for 4 days and it was horrible. This is in an infection in a diverticula that forms in your intestines. It was so bad and fast that it spread with a rapid onset of epididymitis ( infection on the epididymis of your testical). After the hospital I went see my gastro who was a board member of a large anti aging group of doctors. We did bloodwork and My testosterone levels were lower than a woman! Like 110. He also explained to me that I had probably never fully recovered normal test levels from my last “get in shape” run with pro hormones 2 years before and it probably played a part in the weakening of my intestinal wall and immune system and after discussion I realized that I had exhibited all of the text book effects of low T to the letter. After spilling my guts to my doctor we decided upon the gel. It worked great but having kids around I was worried about it affecting them so we switched to in ejections taken every 2 weeks of cypionate 200mg and my wife helps me with that at home and I never stray from the regime . My levels are around 700 to 750 and basically PSA that is non existent. I am now 41 and feel great , go to Doctor twice a year for bloodwork and all is well. My doctor also tells me that in his opinion our environmental factors play a huge role in this, meaning hormones in meats, milks, public water etc. and because of that together with “Poor decision making (me in highschool, college etc) America is in the midst of an epidemic that is being under advertised and overlooked. I constantly read up on the latest info I can find and I liked reading this and your posts. Sometimes I feel guilty because I get comments on how I look and my energy levels and I wonder is this too good to be true? But if I am following a strict regiment and bloodwork reports good things…. Do I need to worry about anything else??? This is my story and I have never shared it with ANYONE other than my wife. Big move for me!! Last point……. This is a generalization but…….all women take hormones. It’s is universally accepted and part of a woman’s life without a doubt. Why is it Taboo to publicly discuss men and hormones? I guarantee if you are a man 35 and above and you did dumb things like me and or exhibit symptoms of low T, do yourself a huge favor and go see a doctor and get blood work done. More than likely you have it! I still hide all of this and I don’t want to shout it out because I feel embarrassed. WHY? Enough already!!!!
Transdermal preparations of testosterone utilize the fact that the skin readily absorbs steroid hormones. Initial transdermal preparations took the form of scrotal patches with testosterone loaded on to a membranous patch. Absorption from the scrotal skin was particularly good and physiological levels of testosterone with diurnal variation were reliably attained. The scrotal patches are now rarely used because they require regular shaving or clipping of scrotal hair and because they produce rather high levels of dihydrotestosterone compared to testosterone (Behre et al 1999). Subsequently, non-scrotal patches were developed but the absorptive capacity of non-scrotal skin is much lower, so these patches contain additional chemicals which enhance absorption. The non-scrotal skin patches produce physiological testosterone levels without supraphysiological dihydrotestosterone levels. Unfortunately, the patches produce a high rate of local skin reactions often leading to discontinuation (Parker and Armitage 1999). In the last few years, transdermal testosterone gel preparations have become available. These require daily application by patients and produce steady state physiological testosterone levels within a few days in most patients (Swerdloff et al 2000; Steidle et al 2003). The advantages compared with testosterone patches include invisibility, reduced skin irritation and the ability to adjust dosage, but concerns about transfer to women and children on close skin contact necessitate showering after application or coverage with clothes.
Findings that improvements in serum glucose, serum insulin, insulin resistance or glycemic control, in men treated with testosterone are accompanied by reduced measures of central obesity, are in line with other studies showing a specific effect of testosterone in reducing central or visceral obesity (Rebuffe-Scrive et al 1991; Marin, Holmang et al 1992). Furthermore, studies that have shown neutral effects of testosterone on glucose metabolism have not measured (Corrales et al 2004), or shown neutral effects (Lee et al 2005) (Tripathy et al 1998; Bhasin et al 2005) on central obesity. Given the known association of visceral obesity with insulin resistance, it is possible that testosterone treatment of hypogonadal men acts to improve insulin resistance and diabetes through an effect in reducing central obesity. This effect can be explained by the action of testosterone in inhibiting lipoprotein lipase and thereby reducing triglyceride uptake into adipocytes (Sorva et al 1988), an action which seems to occur preferentially in visceral fat (Marin et al 1995; Marin et al 1996). Visceral fat is thought to be more responsive to hormonal changes due to a greater concentration of androgen receptors and increased vascularity compared with subcutaneous fat (Bjorntorp 1996). Further explanation of the links between hypogonadism and obesity is offered by the hypogonadal-obesity-adipocytokine cycle hypothesis (see Figure 1). In this model, increases in body fat lead to increases in aromatase levels, in addition to insulin resistance, adverse lipid profiles and increased leptin levels. Increased action of aromatase in metabolizing testosterone to estrogen, reduces testosterone levels which induces further accumulation of visceral fat. Higher leptin levels and possibly other factors, act at the pituitary to suppress gonadotrophin release and exacerbate hypogonadism (Cohen 1999; Kapoor et al 2005). Leptin has also been shown to reduce testosterone secretion from rodent testes in vitro (Tena-Sempere et al 1999). A full review of the relationship between testosterone, insulin resistance and diabetes can be found elsewhere (Kapoor et al 2005; Jones 2007).
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.
So much to say, take a look at excelmale.com. it is a resource for men like us that give answers, science and dialogue which addresses our questions. It’s a great resource for men like us. Also, I would say to eliminate blue light before bed from tv and pc screens. Simply use blue light blocking glasses or F.lux from the play store. Also get outside in the sun in the AM. The goal is to restore the circadian rhythm which impacts hormone productiion.

Testosterone is the primary male sex hormone and an anabolic steroid. In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair.[2] In addition, testosterone is involved in health and well-being,[3] and the prevention of osteoporosis.[4] Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss.

Low Testosterone has a big impact on men. Some males suffer debilitating symptoms when their bodies produce insufficient levels of testosterone, resulting in a condition called hypogonadism. Hypogonadism is the decreased functionality of the testes in producing an adequate amount of testosterone. Hypogonadism is not permanent, and can be treated with hormone replacement therapy, specifically Low Testosterone Therapy.
In non-human primates, it may be that testosterone in puberty stimulates sexual arousal, which allows the primate to increasingly seek out sexual experiences with females and thus creates a sexual preference for females.[39] Some research has also indicated that if testosterone is eliminated in an adult male human or other adult male primate's system, its sexual motivation decreases, but there is no corresponding decrease in ability to engage in sexual activity (mounting, ejaculating, etc.).[39]
In effect, older men with low testosterone and age-associated memory impairment (AAMI) did not benefit from short-term treatment with testosterone, as reported in the current issue of the Journal of the American Medical Association (JAMA),1 by Susan M. Resnick, PhD, a senior investigator at the National Institute on Aging in Baltimore, Maryland, and colleagues.
An added testosterone benefit of my high fat and balanced protein and carb diet was that it probably helped me lose some body fat (I went from 18% to 12% body fat). Studies show that high fat diets actually contribute to increased body fat loss. And as we discussed earlier, as you lose body fat, your T production ramps up. Virtuous cycle for the win!
Rest and recovery is just as important as exercise, if not more so. Every time you do an intense workout, give yourself a minimum of 2 days to recuperate afterward, if not more. And don’t mix exercise with sleep hacking. If you’re exercising, get at least 8 hours of sleep every night. Your body uses it to rebuild, and you can throw your hormones out of whack if you don’t rest up properly. Here’s a more in-depth guide to Bulletproof weight training, complete with sample workouts.
Testosterone may prove to be an effective treatment in female sexual arousal disorders,[52] and is available as a dermal patch. There is no FDA approved androgen preparation for the treatment of androgen insufficiency; however, it has been used off-label to treat low libido and sexual dysfunction in older women. Testosterone may be a treatment for postmenopausal women as long as they are effectively estrogenized.[52]
In fact, high cortisol deals a crushing blow to testosterone in two ways. During, long-lasting stress, high amounts of cortisol release very often and have a direct negative influence on T levels. Thus, cortisol inhibits testosterone synthesis in the testes and hypothalamus. In addition, the production of cortisol is impossible without cholesterol. But testosterone synthesis also demands cholesterol. Since during stress cholesterol is first of all used for making cortisol, T levels simply plummet.
Keep in mind that you can use virtually any type of equipment you want for this – an elliptical machine, a treadmill, swimming, even sprinting outdoors (although you will need to do this very carefully to avoid injury) -- as long as you're pushing yourself as hard as you can for 30 seconds. But do be sure to stretch properly and start slowly to avoid injury. Start with two or three repetitions and work your way up, don't expect to do all eight repetitions the first time you try this, especially if you are out of shape.
In addition to that, one positive benefit that this product offers that not all natural testosterone boosters do is that it can help to improve your overall mood state. While maintaining a better mood is clearly a favorable thing, it also helps out in terms of your muscle building results because the better your mood is, the higher your motivation tends to be, which then means more effort put forth in the gym.
Well, this is another area of confusion and great debate, but I don’t think it’s as confusing as it appears to be in the literature. When most doctors learned about testosterone in medical school, they learned about total testosterone, or all the testosterone in the body. But about half of the testosterone that’s circulating in the bloodstream is not available to the cells. It’s tightly bound to a carrier molecule called sex hormone–binding globulin, which we abbreviate as SHBG.
"I am only 10 weeks into taking your product and I have lost 12 pounds and three inches from my waist. Normally I scoff at radio or TV ads promising results like this. But in this case, my results have far exceeded my expectations. My energy level has increased and my appetite has decreased! All this without any extra exercise program. Thanks from a very satisfied customer!"
The rise in testosterone levels during competition predicted aggression in males but not in females.[90] Subjects who interacted with hand guns and an experimental game showed rise in testosterone and aggression.[91] Natural selection might have evolved males to be more sensitive to competitive and status challenge situations and that the interacting roles of testosterone are the essential ingredient for aggressive behaviour in these situations.[92] Testosterone produces aggression by activating subcortical areas in the brain, which may also be inhibited or suppressed by social norms or familial situations while still manifesting in diverse intensities and ways through thoughts, anger, verbal aggression, competition, dominance and physical violence.[93] Testosterone mediates attraction to cruel and violent cues in men by promoting extended viewing of violent stimuli.[94] Testosterone specific structural brain characteristic can predict aggressive behaviour in individuals.[95]

In high-fat high-furctose fed rats, ginger neutralized diet induced impairment in glucose regulation, dyslipidemia, and oxidative stress [28]. This observed anti-diabetic activity of ginger powder is credited to two active components: 6-paradol and 6-shogaol [29]. They both exhibit potent activity in stimulating glucose utilization by 3T3-L1 adipocytes and C2C12 myotubes. In the high-fat diet mouse model, 6-paradol decreased blood glucose, cholesterol and body weight.

I have been on testosterone injections for about six months now. My urologist has me taking 50mg a week. I noticed that when I take the injection my normal resting heart rate is about 61 beats a minute, on the day of the injection it goes up to about 84 BPM. I also notice a tightness in my chest/esophagus area for about 24-48 hours and than it subsides. I have also noticed it appears to make my eyes water on the day of the injection. I have gotten off the injections because that is the obvious thing to do, but the dillema is than my personal life with the wife suffers. I am in great shape and work out all the time. Is there anything you can recommended I do to mitigate the increased blood pressure and increased heart beat? My last blood test showed normal except my estrogen was right at the recommended max but still with in limits. Any advice would be appreciated.

I used to give a duration of 9 weeks between shots during early days when I commenced this form of medication. Which then, gradually made me reduce to 8 weeks, then 7 weeks since last year and now I had to intake this after 4th week which is the least duration I gave. I have started to find this pattern risky for the other health hazards due to over dosage.

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.
during therapy. It is very hard to find a local endo who is thinking with his head vs complying with old trt programs. I tool clomid in the past to see what it would do and it elevated my t level to 520 in 2 weeks from low 220. Aromason will do same but clomid is more potent. Not sure what the long effect would be since you tend to get bit moody on clomid after 2 months. LH is also being affected in negative way since the lh receptors can burn out to a degree. I will contact the trt clinic in order to start my trt as they have much more experience with these things.

“Before taking Andro400, my husband weighed 290 lbs. He's a diabetic and his blood pressure was through the roof. I purchased Andro based on the reviews, and he's lost 60 - 70 lbs! ​It's enhanced him health-wise in a lot of aspects too. He used to be depressed because of his weight. The fact that he was losing weight like crazy gave him a lot of relief. He's not depressed now, he's really happy. He's more loving. And it's so exciting for me as a wife to see him happier -- it made me happier​! ​ So I'm really grateful. Andro400 gave him a lot of ​energy ​ too because of the testosterone boost.​ The 3 main things everybody's noticing are: no more​ depression, a lot more energy and ​the huge weight loss. He went from size 42 to 38, so it's like, oh my God it's WORKING!! Trust me, we've tried a lot of other things that didn't work. And that's why I'm so excited because it's actually, literally changing our lives!”

A man with shrinking levels of testosterone actually may lose some body hair. Testosterone replacement therapy comes with a few potential side effects, including acne and breast enlargement. Testosterone patches may cause minor skin irritation. Topical gels may be easier to use, but great care must be taken to avoid transferring testosterone to someone else though skin-to-skin contact.
A: Depo-Testosterone is a brand name medication that contains testosterone cypionate. Depo-Testosterone is given as an intramuscular injection. The medication is indicated for replacement therapy for men that have conditions associated with symptoms of deficiency in the hormone or absence of testosterone produced in the body. Conditions that can be associated with low testosterone include: delayed puberty, impotence and hormonal imbalances. Testosterone is a sex hormone that is naturally produced in the male testicles. In women, small amounts of testosterone is produced in the ovaries and by the adrenal system. Testosterone is available in various medications for testosterone replacement therapy. Different forms of testosterone (e.g. cypionate, enanthate etc) are contained in different brand name medications. Jen Marsico, RPh
I am 51 male. I have had low T for a few years now. I was using Testim for a few years, but I hated the smell and mostly feared getting thus stuff on the kids. The reason I stopped with all that nasty gel is because my T levels weren’t improving. So, why bother using anything that is not working, so I stopped. Apparently I am one of those men who do not absorb the gel very well. My T levels dropped from a low of around 200 on a 800+ scale to under 100 after I stopped using the gel.
In this study, an ethical approval No. 20171008 was obtained from Ethical Committee of Qassim province, Ministry of Health, Saudi Arabia. At the beginning, a written informed consent was taken from a 30-year-old man for participation in this study. The patient came to the King Saud Hospital, Unaizah, Qassim, Saudi Arabia, with abdominal pain. He looked pale and hazy, hence, immediately admitted. A battery of lab tests was ordered by the attending physician. Moreover, abdominal ultrasound imaging was performed. The results of the tests showed high levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indicating liver injury. Other serum parameters, such as total proteins, albumin, and iron, in addition to the levels of kidney and heart enzymes were all found to be in the normal range. A complete blood count showed normal levels of red blood cells, white blood cells, and platelets. The ultrasound images of the man’s abdomen were all found to be normal as well [Figure 2]. The patient, a sportsman, described that he was taking a testosterone commercial booster product called the Universal Nutrition Animal Stak for the purpose of enhancing his testosterone profile to achieve a better performance and body composition. The attending physician decided to admit the man for 1 week. Some medications were prescribed, and the patient was discharged later after having fully recovered.

So, this past summer I talked with my doctor about starting T injections to see if that would work. I started injection 1 small bottle every 2 weeks. I started some time in later July, 2016. After around the 3 injection I had a blood test and my T level was OVER 800, something like 832. Apparently, my body reacted and took to it very quickly and easily, but the T level was now TOO high. So, I extended the injection interval to 18 days instead of 15 days. I just had another blood test last week and my T level was in the mid 600’s. It’s better now, but my doctor and I want to get that down to around 500, so I’m going to 20-21 days and see what happens.

As with cognitive effects, previous studies examining CVD changes following testosterone treatment have been conflicting and inconclusive. Dr. Budoff and his research team used coronary computed tomographic angiography (CCTA) to assess 138 men, including 73 treated with testosterone and 65 receiving placebo, for changes in coronary artery plaque volume after 1 year.

• 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.
Before assessing the evidence of testosterone’s action in the aging male it is important to note certain methodological considerations which are common to the interpretation of any clinical trial of testosterone replacement. Many interventional trials of the effects of testosterone on human health and disease have been conducted. There is considerable heterogenicity in terms of study design and these differences have a potential to significantly affect the results seen in various studies. Gonadal status at baseline and the testosterone level produced by testosterone treatment in the study are of particular importance because the effects of altering testosterone from subphysiological to physiological levels may be different from those of altering physiological levels to supraphysiological. Another important factor is the length of treatment. Randomised controlled trials of testosterone have ranged from one to thirty-six months in duration (Isidori et al 2005) although some uncontrolled studies have lasted up to 42 months. Many effects of testosterone are thought to fully develop in the first few months of treatment but effects on bone, for example, have been shown to continue over two years or more (Snyder et al 2000; Wang, Cunningham et al 2004).