Low testosterone in men can result in:

1. Fatigue, tiredness or loss of energy
2. Depression, low or negative mood
3. Irritability, anger or bad temper
4. Anxiety or nervousness
5. Loss of memory or concentration
6. Relationship problem with partner
7. Loss of sex drive or libido
8. Erection problems during sex
9. Loss of morning erections
10. Decreased intensity of orgasms
11. Backache, joint pains or stiffness
12. Heavy drinking, past or present
13. Loss of fitness
14. Feeling over-stressed
15. Loss of drive and competitive edge
16. Stiffness and pain in muscles and joints
17. Falling level of fitness
18. Decreased effectiveness of workouts

Testosterone replacement and optimization can result in:

1. Decreased aging of heart and circulation
2. Decreased risk of heart attacks and strokes
3. Decreased risk of diabetes
4. Decreased body Fat
5. Increased lean muscle
6. Increased blood flow to brain
7. Decreased brain aging
8. Improved memory and intelligence
9. Decreased risk of dementia and Alzheimer's
10. Increased sense of well being
11. Improved Sexual function
12. Decreased Osteoporosis
13. Decreased risk of prostate cancer

Average testosterone levels in older vs. younger men

Low testosterone linked to long-term risk of death in relatively healthy adult men
ENDO 2007: The Endocrine Society Research Summaries Book June 5, 2007

This study is another major report linking deficiency of testosterone in relatively healthy men with increased death from all causes, over time. “We have followed these men for an average of 18 years and our study strongly suggests that the association between testosterone levels and death is not simply due to some acute illness," said Gail Laughlin, Ph.D., assistant professor and study author.

In the study, Laughlin and co-workers looked at death, no matter the cause, in nearly 800 men, ages 50 to 91 years, who were living in California since 1970. At the beginning of the 1980s, almost one-third of these men had suboptimal blood testosterone levels for men their age.

The group with low testosterone levels had a 33 percent greater risk of death during the next 18 years than the men with higher testosterone. This difference was not explained by smoking, drinking, physical activity level or pre-existing diseases (such as diabetes or heart disease). Men with low testosterone were more likely to have elevated markers of inflammation, called inflammatory cytokines, which contribute to many diseases. Men with low testosterone were also shown to be three times more likely to have a waist measurement more than 40 inches, low HDL (good) cholesterol, high triglycerides (levels of fat in the blood), high blood pressure or high blood glucose (blood sugar).

This study is further confirmation of previous studies that demonstrate an increased risk of morbidity and mortality with low or low normal testosterone:

• In a study of male veterans, low serum testosterone levels were shown to increase the risk of death in the next few years by 88%, according to a report in the Archives of Internal Medicine.
• In an earlier study, Dr. Molly M. Shores and colleagues from the University of Washington in  Seattle and showed an increase in 6-month mortality among men with low testosterone levels.
• The another study published in a 2006 edition of the Archives of Internal Medicine involved 858 male veterans who were at least 40 years of age, prostate cancer-free, and had repeated testosterone levels taken between 1994 and 1999 and were followed for an average of 4.3 years. It was found that men with low or low normal testoerone had a 23-75% increased risk of dying.

1. Bringing testosterone form low normal to high normal lowers the risk for heart disease by 60%
The Journal of Clinical Endocrinology & Metabolism. Aug 2002. Vol. 87, No. 8 3632-3639

2. 2 year study of low dose testosterone on libido in men
(Clin Endocrinol Metab 1997)

3. Dihydrotestoerone reduces prostate size
Ann Med 1993 Jun;25(3):235-41

3. Testosterone Improves Sexual Function, Mood, Muscle Strength, and Body Composition Parameters in Hypogonadal Men Improved

a. Sexual function
b. mood
c. muscle strength, leg > arm
d. Subjects did not exercise
e. Improved lean body mass and fat mass
f. Correlated with serum level of T obtained

Study showed that these benefits were not obtained with testosterone patches (Testosterone patches are too weak for most patients)

5. Testosterone supplementation increased working memory in men
Janowsky J et al. Sex steroids modify working memory J Cogn Neurosci 2000 May;12(3):407-14

6. Testosterone replacement reduces the risk of Alzheimer’s Disease by preventing the production of beta amyloid precursor protein.
Gouras GK et al. Proc Natl Acad Sci U S A 2000 Feb 1;97(3):1202-5

7. Testosterone levels correlates with and testosterone replacement improves cognitive function
Hormones and Behavior 1998; 33(2):85-94.
J Clin Endocrinol Metab 1999 Oct;84(10):3681-5

8. Testosterone replacement is more effective than antidepressants for depression
Am J Psychiatry 157:1884, November 2000
Androl 1992 Jul-Aug;13(4):297-304

9. Low testosterone associated with fatigue and testosterone replacement increases sense of well being
Many patients are able to stop Antidepressants after being treated with testosterone
Geriatr Psychiatry Neurol 2000 Summer;13(2):93-101

10. The lower the active testosterone level, the higher the risk for heart attack.
Circulation 1999 Apr 6;99(13):1666-70

- Acute anti-ischemic effect of testosterone in men with coronary artery disease.
- Testosterone improves exercise induced ST depression
- Dilates coronary arteries
 “Short-term administration of testosterone induces a beneficial effect on exercise induced  myocardial ischemia in men with coronary artery disease. This effect may be related to a direct  coronary-relaxing effect.”

11. Men with heart disease have significantly lower
- Total testosterone
- Free testosterone
- Bioavailability testosterone
- Men with coronary artery disease have lower levels of androgens than men with normal coronary angiograms.
Eur Heart J 2000 Jun;21(11):890-4

12. Low testosterone increases the risk of heart disease and more optimal levels decrease the risk of heart disease.
Int J Obes Relat Metab Disord, July 2003

13. Low testosterone levels increase the risk of prostate cancer and testosterone replacement is expected to reduce risk of prostate cancer.
Dihydrotestosterone and testosterone levels in men screened for prostate cancer: a study of a randomized population.
Br J Urol 1996 Mar;77(3):433-40

- DHT is lower in prostate cancer patients
- DHT is lower in prostate cancer patients
- DHT is lower in more advanced tumors
- PSA and DHT have an inverse relationship (high DHT lower PSA)

14. Testosterone replacement is better than exercise to reduce body fat, gain lean muscle and improve strength and effects of testosterone are improved with exercise (Synergistic effect)
J Endocrinol 2001 Jul;170(1):27-38

15. Testosterone replacement reduces risk of diabetes
- Testosterone replacement decreases insulin resistance
- Low levels of testosterone play a role in the development of type 2 diabetes
- Elevated insulin decreases testosterone levels resulting in a vicious cycle of worsening insulin resistance and reduced testosterone levels
- Testosterone replacement breaks this cycle
- Low testosterone is associated with Syndrome X, hypertension, type 2 diabetes and heart disease.
Journal of American Epidemiology 1996
Int J Obes Relat Metab Disord 2000
Mayo Clin Proc 2000 Jan;75 Suppl:S61-4
Diabetes Care. 2000 Apr;23(4):490-4
Metabolism 1997 May;46(5):526-9

16. Dihydrotestoterone with NSAIDS kills prostate cancer cells
Cancer Chemother Pharmacol, 2002; 49(3):179-86

17. Using HCG to boost testosterone levels results in significant improvement in prostate enlargement and symptoms
Journal of Urology 2003

18. Testosterone replacement decreases fat and increases lean muscle.
Bhasin et al. journal of Endocrinology and Metabolism, 2003

19. Testosterone replacement speeds healing and result s in shortens hospital stays.
Journal Am Geriatr Soc, 2002

20. Pesticides reduce testosterone production in men
Biology and Reproduction, 2003

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Testosterone Prevents Mental Decline in Aging Males
Longitudinal Assessment of Serum Free Testosterone Concentration Predicts Memory Performance and Cognitive Status in Elderly Men
The Journal of Clinical Endocrinology & Metabolism. Vol. 87, No. 11 5001-5007 

Abstract: Circulating testosterone (T) levels have behavioral and neurological effects in both human and nonhuman species. Both T concentrations and neuropsychological function decrease substantially with age in men. The purpose of this prospective, longitudinal study was to investigate the relationships between age-associated decreases in endogenous serum T (testosterone) and free T concentrations and declines in neuropsychological performance. Participants were volunteers from the Baltimore Longitudinal Study of Aging, aged 50–91 yr at baseline T assessment. Four hundred seven men were followed for an average of 10 yr, with assessments of multiple cognitive domains and contemporaneous determination of serum total T, SHBG, and a free T index (FTI). We administered neuropsychological tests of verbal and visual memory, mental status, visuomotor scanning and attention, verbal knowledge/language, visuospatial ability, and depressive symptomatology.

Higher free testosterone was associated with better scores on visual and verbal memory, visuospatial functioning, and visuomotor scanning and a reduced rate of longitudinal decline in visual memory. Men classified as hypogonadal (low testosterone) had significantly lower scores on measures of memory and visuospatial performance and a faster rate of decline in visual memory. These results suggest a possible beneficial relationship between circulating free Testosterone concentrations and specific domains of cognitive performance in older men.

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Researchers in the Netherlands studied genital arousal in women after the administration of testosterone and reported their findings in the February 2000 issue of the Archives of General Psychiatry. Sublingual testosterone was shown to trigger sexual desires, fantasies and lust along with an increase in vaginal arousal.

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