Testosterone is a steroid from the androstane class containing a keto and hydroxyl groups at the three and seventeen positions respectively. It is biosynthesized in several steps from cholesterol and is converted in the liver to inactive metabolites.[5] It exerts its action through binding to and activation of the androgen receptor.[5] In humans and most other vertebrates, testosterone is secreted primarily by the testicles of males and, to a lesser extent, the ovaries of females. On average, in adult males, levels of testosterone are about 7 to 8 times as great as in adult females.[6] As the metabolism of testosterone in males is more pronounced, the daily production is about 20 times greater in men.[7][8] Females are also more sensitive to the hormone.[9]
The Organon group in the Netherlands were the first to isolate the hormone, identified in a May 1935 paper "On Crystalline Male Hormone from Testicles (Testosterone)".[180] They named the hormone testosterone, from the stems of testicle and sterol, and the suffix of ketone. The structure was worked out by Schering's Adolf Butenandt, at the Chemisches Institut of Technical University in Gdańsk.[181][182]
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).
It is important to note that you can certainly boost testosterone naturally without supplementation. Supplements are expensive now a days and a lot of people do not like taking tons of pills. Plus, a lot of these vitamins and minerals are only needed if deficient, so I recommend getting routine blood work done to see where you are short. I can almost guarantee you will come out vitamin D deficient, so while you don’t have to take these, they will certainly help.
Any day that you don’t get 20 minutes of direct sunlight on your skin, you want to supplement with 5,000 IUs of vitamin D3. If you get your blood levels tested and you’re extremely low — below 50 IUs — you typically want to do 5,000 IUs twice a day for three months until you get those numbers up. You can do everything in the world, but if your vitamin D levels aren’t right, your testosterone levels will stay low.
Grape seed extract is another ingredient with not enough research to suggest a dosage. Grape seed extract can interact with drugs like “blood thinners, NSAID painkillers (like aspirin, Advil, and Aleve), certain heart medicines, cancer treatments, and others.” If this sounds like you (or if you ever pop an Advil to clear off a headache), you’ll need to speak with a doctor to make sure this supplement is safe to take.
Other side effects include increased risk of heart problems in older men with poor mobility, according to a 2009 study at Boston Medical Center. A 2017 study published in JAMA found that treatments increase coronary artery plaque volume. Additionally, the Food and Drug Administration (FDA) requires manufactures to include a notice on the labeling that states taking testosterone treatments can lead to possible increased risk of heart attacks and strokes. The FDA recommends that patients using testosterone should seek medical attention right away if they have these symptoms:
5. Beef.  Is there a manlier food than steak? Release your inner carnivore if you want to boost your testosterone level. Lean beef is rich with zinc, saturated fat, iron, protein and magnesium. We’ve already mentioned earlier on how zinc can enhance the production of testosterone. Lean beef can be an excellent food choice, since you can increase your testosterone level and muscle mass at the same.

‘Testosterone boosting’ products  - found online, or in health food or body-building shops, these products claim to boost testosterone levels if you buy them. The majority of these products will not have the effect you want and are not worth spending money on. Any of these products that do have a real effect may have a form of prescription medication in which is both dangerous and illegal.

Overall, it seems that both estrogen and testosterone are important for normal bone growth and maintenance. Deficiency or failure of action of the sex hormones is associated with osteoporosis and minimal trauma fractures. Estrogen in males is produced via metabolism of testosterone by aromatase and it is therefore important that androgens used for the treatment of hypogonadism be amenable to the action of aromatase to yield maximal positive effects on bone. There is data showing that testosterone treatment increases bone mineral density in aging males but that these benefits are confined to hypogonadal men. The magnitude of this improvement is greater in the spine than in the hip and further studies are warranted to confirm or refute any differential effects of testosterone at these important sites. Improvements seen in randomized controlled trials to date may underestimate true positive effects due to relatively short duration and/or baseline characteristics of the patients involved. There is no data as yet to confirm that the improvement in bone density with testosterone treatment reduces fractures in men and this is an important area for future study.

If a young man's low testosterone is a problem for a couple trying to get pregnant, gonadotropin injections may be an option in some cases. These are hormones that signal the body to produce more testosterone. This may increase the sperm count. Hedges also describes implantable testosterone pellets, a relatively new form of treatment in which several pellets are placed under the skin of the buttocks, where they release testosterone over the course of about three to four months. Injections and nasal gels may be other options for some men.