^ Jump up to: a b Sapienza P, Zingales L, Maestripieri D (September 2009). "Gender differences in financial risk aversion and career choices are affected by testosterone". Proceedings of the National Academy of Sciences of the United States of America. 106 (36): 15268–73. Bibcode:2009PNAS..10615268S. doi:10.1073/pnas.0907352106. PMC 2741240. PMID 19706398.
Here’s one proof: in a number of British rivers, 50 percent of male fish were found to produce eggs in their testes. According to EurekAlert,3 EDCs have been entering rivers and other waterways through sewage systems for years, altering the biology of male fish. It was also found that fish species affected by EDCs had 76 percent reduction in their reproductive function.
Vitamin D3. Vitamin D3 actually isn’t a vitamin, it’s a hormone — a really important hormone that provides a whole host of health benefits. Our bodies can naturally make vitamin D from the sun, but recent studies have shown that many Westerners are vitamin D3 deprived because we’re spending less and less time outdoors. When we do decide to venture outside, we slather our bodies with sunscreen, which prevents the sun reaching our skin to kick-off vitamin D3 production. If you’re not getting enough sun, you may have a vitamin D3 deficiency, which may contribute to low T levels. If you think you need more vitamin D3, supplement it with a pill. Studies have shown that men who take this supplement see a boost in their testosterone levels. Because I have a darker complexion — which makes me prone to Vitamin D3 deficiency — I took 4,000 IU of vitamin D3 in the morning.
Hypogonadism (as well as age-related low testosterone) is diagnosed with blood tests that measure the level of testosterone in the body. The Endocrine Society recommends testing for suspected low T with a total testosterone test. It may be performed in the morning when testosterone levels tend to be highest in young men, although this isn't necessarily the case in older men. The test may be repeated on another day if the results show a low T level. (5)
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Great article with a lot of useful information. I completely agree with your top three picks. I have done a ton of research as well. Currently I am taking Testogen for over two months and it has worked for me. It has double my low T and I am 61 years old. I do feel better and have more energy. Even have morning wood sometimes and haven’t for a long time.
There is a polymorphic CAG repeat sequence in the androgen receptor gene, which codes for a variable number of glutamine amino acids in the part of the receptor affecting gene transcription. A receptor with a short CAG sequence produces greater activity when androgens attach, and men with shorter CAG polymorphisms exhibit androgenic traits, such as preserved bone density (Zitzmann et al 2001) and prostate growth during testosterone treatment (Zitzmann et al 2003). Indirect evidence of the importance of androgens in the development of prostate cancer is provided by case control study findings of a shorter, more active CAG repeat sequence in the androgen receptor gene of patients with prostate cancer compared with controls (Hsing et al 2000, 2002).

A blood test is the only way to diagnose a low testosterone level or a reduction in the bioavailability of testosterone. Some men have a lower than normal testosterone level without signs or symptoms. For most men, no treatment is needed. But for some others, very low testosterone levels lead to a condition in which bones become weak and brittle (osteoporosis). For others, low testosterone might cause changes in sexual function, sleep patterns, emotions and the body.
Male sex characteristics greatly depend on testosterone synthesis in your body. If you keep the levels of this hormone normal, you will prevent sexual potency issues. Accordingly, the elevation of testosterone levels helps combat the impairment of erectile function. The levels of this hormone also affect male fertility. If these levels grow, fertility improves. Aging has a negative impact on testosterone secretion. Such hormonal imbalance is inevitable and permanent. But it’s still possible to positively change the situation and stimulate hormone production by using the high-quality testosterone boosters.
The aim of treatment for hypogonadism is to normalize serum testosterone levels and abolish symptoms or pathological states that are due to low testosterone levels. The exact target testosterone level is a matter of debate, but current recommendations advocate levels in the mid-lower normal adult range (Nieschlag et al 2005). Truly physiological testosterone replacement would require replication of the diurnal rhythm of serum testosterone levels, but there is no current evidence that this is beneficial (Nieschlag et al 2005).

On the average, you need to sleep at least 8 hours per night to stay healthy. If you want a night sleep to contribute to the maximum testosterone production, it’s important to make your sleep comfortable. Thus, the bedroom temperature shouldn’t exceed 21°C. In addition, you should ventilate your bedroom thoroughly before sleeping. Furthermore, before going to bed, don’t overload your stomach with fatty foods, as well as don’t drink alcohol and caffeinated beverages. Finally, you have to avoid intense physical activity before bedtime.6
The changes in average serum testosterone levels with aging mean that the proportion of men fulfilling a biochemically defined diagnosis of hypogonadism increases with aging. Twenty percent of men aged over 60 have total testosterone levels below the normal range and the figure rises to 50% in those aged over 80. The figures concerning free testosterone are even higher as would be expected in view of the concurrent decrease in SHBG levels (Harman et al 2001).
A loophole in FDA regulations allows pharmaceutical marketers to urge men to talk to their doctors if they have certain "possible signs" of testosterone deficiency. "Virtually everybody asks about this now because the direct-to-consumer marketing is so aggressive," says Dr. Michael O'Leary, a urologist at Harvard-affiliated Brigham and Women's Hospital. "Tons of men who would never have asked me about it before started to do so when they saw ads that say 'Do you feel tired?'"