Men’s levels of testosterone naturally decrease 1% after the age of 30 years of age. There is also andropause where men’s hormones are off later in life. There are ways that you can preserve your levels naturally.
The website drmercola.com has great tips about how to boost your testosterone naturally.
There are differences between testosterone cream and injections. Injections shut down the production of testosterone. They also raise the testosterone levels drastically at the time of injection but then decrease during the week. So the levels vary. Creams give more stable levels every day. They also seem to have an effect on lipid levels.