I disagree with 4 weeks on being due to the toxic levels of some products! "Long steroid cycles can cause a host of problems. For this reason, a steroid cycle should not go beyond 4 weeks
The most important reason why you should keep your cycles short is because of the side effects that are associated with long cycles. For one, there will be a drastic shift in your lipid profile. Your levels of HDL (good cholesterol) will come down while the level of LDL (bad cholesterol) goes up. This can increase the risk of heart disease.
As the cycle progresses, the body's own production of hormones such as Follicle Stimulating Hormone, Luteinizing Hormone and Testosterone slow down and eventually shut down all together. But there will be a fairly high level of Estrogen (from the aromatization of Testosterone) and a normal level of Cortisone.
There is an enzyme called aromatase, whose main purpose is to catalyze the conversion of Testosterone into Estrogen. The male body needs Estrogen, which plays an important role in the maturation of sperms but too much of it can have negative effects. It can lead to testicular atrophy, low libido, enlarged nipples, muscle mass loss and even potentially fatal health issues such as stroke, hormonal cancers and heart attack.
Cortisone, an anti-stress hormone has a catabolic effect on muscle mass but it is usually suppressed by Testosterone. When adequate amounts of Testosterone are not present, Cortisone has a free hand and it starts liquidating the muscle mass that you may have developed through the use of a synthetic anabolic steroid.
The longer your steroid cycle, longer will be the time it will take for your body to renew its production of natural Testosterone. One of the side effects of long term steroid use is an atrophication of the Leydig cells of the testes. When the steroid cycle ceases, the Leydig cells are not able to restart the production of Testosterone immediately because at this point they are desensitized to the effect of the gonodotrophins.
Eventually they will respond and the body will kick start its production of Testosterone but not before you have been through a lot of discomfort. This is the reason why post-cycle therapy is an absolute must after the end of a cycle."
Obviously I'm not talking about andros, more DS and strong bouts of gear! True solidifying the end part of your gains is nice but every week on makes it harder for your body to recover fully! With diet and training on point I wouldn't see why you'd lose anything other than glycogen and water storage anyways