The structure of cyclocreatine is fairly flat (planar), which aids in passive diffusion across membranes. It has been used with success in an animal study, where mice suffered from a SLC6A8 (creatine transporter at the blood brain barrier) deficiency, which is not responsive to standard creatine supplementation.  This study failed to report increases in creatine stores in the brain, but noted a reduction of mental retardation associated with increased cyclocreatine and phosphorylated cyclocreatine storages.  As demonstrated by this animal study and previous ones, cyclocreatine is bioactive after oral ingestion   and may merely be a creatine mimetic, able to phosphorylate ADP via the creatine kinase system. 
A cutting Deca Durabolin cycle will normally not be built around this Nandrolone hormone, but rather it is a secondary addition. In the cutting phase, this steroid may be added to a total plan in order to promote muscle tissue preservation, but it is most commonly added for the therapeutic effects this steroid can provide. If a cutting Deca Durabolin cycle is implemented, especially if you’re a competitive bodybuilder, you will more than likely want to keep its use at the front end of the total plan and rely solely on hardening agents towards the end. This type of Deca Durabolin cycle cannot be recommended to new steroid users . This type of use will normally be extended beyond what a new steroid user will be comfortable with.
AI’s are also sometimes used during PCT because of their ability to stimulate LH and FSH. However, they also lower estrogen levels and often too much during this phase. Part of the PCT plan is to allow the body to normalize and part of that is maintaining normal estrogen levels. Estrogen is not an evil hormone many men, especially steroid users often believe it is. Estrogen is extremely important for muscle building, sexual health, mental health and a host of other areas. Estrogen levels that are too high or too low, both can be very problematic.