Facts

 Testosterone is a hormone produced primarily in the testicles. Testosterone helps maintain men's:  

• Bone density
• Fat distribution
• Muscle strength and mass
• Facial and body hair
• Red blood cell production
• Sex drive
• Sperm production

 Testosterone levels generally peak during adolescence and early adulthood. As you age, your testosterone level gradually declines — typically about 1% a year after age 30 or 40. For older men, it's important to determine if a low testosterone level is due to normal aging or if it is due to a disease (hypogonadism).

Hypogonadism hampers the ability to produce normal amounts of testosterone due to a problem with the testicles or with the pituitary gland that controls the testicles. Testosterone replacement therapy, in the form of injections, pellets, patches or gels, can improve the signs and symptoms of low testosterone in these men.

Not necessarily. Men can have many signs and symptoms as they age. Some that might occur as a result of lower testosterone levels can include:

• Changes in sexual function. This might include reduced sexual desire, fewer spontaneous erections — such as during sleep — and infertility.
• Physical changes. Various physical changes are possible, including increased body fat, reduced muscle bulk and strength, and decreased bone density. Swollen or tender breasts (gynecomastia) and body hair loss are possible. You might have less energy than you used to.
• Emotional changes. Low testosterone can contribute to a decrease in motivation or self-confidence. You might feel sad or depressed, or have trouble concentrating or remembering things.

Some of these signs and symptoms can be caused by other factors, including medication side effects, obstructive sleep apnea, thyroid problems, diabetes and depression. It's also possible that these conditions cause low testosterone levels, so treatment might result in increase of testosterone levels.

A blood test is used to diagnose a low testosterone level.

Testosterone therapy has various risks, including:

• Worsening sleep apnea — a potentially serious sleep disorder in which breathing repeatedly stops and starts.
• Causing acne or other skin reactions.
• Stimulating noncancerous growth of the prostate (benign prostatic hyperplasia) and growth of existing prostate cancer.
• Enlarging breasts.
• Limiting sperm production or causing testicles to shrink.
• Stimulating too much red blood cell production, which contributes to the increased risk of forming a blood clot. A clot could break loose, travel through your bloodstream and lodge in your lungs, blocking blood flow (pulmonary embolism).

Also, some research shows that testosterone therapy can increase your risk of heart disease. More research is needed. 

Retrieved from:

https://www.mayoclinic.org/healthy-lifestyle/sexual-health/in-depth/testosterone-therapy/art-20045728

 Cyanocobalamin is a man-made form of vitamin B12 used to treat low levels (deficiency) of this vitamin. Vitamin B12 helps your body use fat and carbohydrates for energy and make new protein. It is also important for normal blood, cells, and nerves. Most people get enough vitamin B12 in their diet, but a deficiency may occur in certain health conditions (such as poor nutrition, stomach/intestinal problems, infection, cancer). Serious vitamin B12 deficiency may result in anemia, stomach problems, and nerve damage.