You can find two ways to get more steroid testosterone into your body. You either stimulate your testicles into producing more, or you take some type of synthetic junk to replace what your body could have made. Typically the negative side effects only are derived from using synthetic human hormones - boosting your testicle's production do not have known part effects whatsoever.
Using man made drugs can cause your body to stop producing testosterone because the brain detects there is already too much. In fact the synthetics will stimulate estrogen production in order to try and balance out the excess of steroids in the body. Taking artificial steroids helmut strebl will also reduce the testicles simply because they are no lengthier being utilized to make ejaculation and testosterone. Which of course causes the other side effect - that being that men on these synthetic drugs typically are infertile; made sterile and clean by the flood of medication in their system which close down the testicles doing anything useful? Lastly, there is a risk of building prostate cancer as it has been known for some time that it is androgenic hormone or testosterone that can make a tiny cancer become quite aggressive. So, besides breaking the law by taking unlawful steroid hormones, there is serious health problems associated with these drugs.
Contrast this with naturally increasing your own body to make the hormones it needs, there is increased fertility because your testicles are always busy being active doing what they should be doing. There is not any disproportionate production of estrogen because the higher level of testosterone is the desired result wanted by the brain, rather than the brain trying to control a overflow of foreign drugs. In addition to no risks of prostatic cancers because the increased testosterone is expected and desired by the natural systems within the body. And because the testicles are busy constantly, there is no shrinkage in size.