While there has been no definite information published as to who should not take pregnenolone, on theoretical grounds, a few cautions can be suggested. Since pregnenolone (especially at high doses) may (in some people) increase estrogen or testosterone levels, I believe that men with prostate cancer (which may be worsened by testosterone) and women with breast or ovarian cancer (which may be worsened by estrogen) should probably take pregnenolone only with their doctors consent and supervision. Men with high PSA (prostate specific antigen) blood levels (possible indicator for undiagnosed or future prostate cancer) should also proceed with caution with pregnenolone use. Lastly, because of pregnenolones anti-GABA, pro-NMDA action, persons known to suffer from epileptic seizures or who are taking an anti-seizure medication such as Dilantin, Depakote or Tegretol should probably only use pregnenolone with their doctors supervision. Finally, as we age, the body produces ever-less of the enzyme which converts pregnenolone to DHEA. Thus, while supplementary pregnenolone taken during middle age and beyond will produce at least some normalization back toward more youthful (and healthful) levels of other steroid hormones, pregnenolone will not completely substitute for other steroid hormone supplements in those with medically demonstrated needs for various specific steroids ., DHEA, cortisol, estrogen, etc.
Equipoise can produce androgenic side effects such as acne, accelerated hair loss in those predisposed to male pattern baldness and body hair growth. However, the overall androgenicity of this steroid is greatly reduced due to the structural nature that creates EQ in its double bond at the carbon one and two position. Such side effects of Equipoise are still possible, but they will be strongly linked to genetic predisposition, but most will find the threshold is fairly high.
When combating the possible androgenic side effects of Equipoise, it’s important to note they are brought on by the steroid being metabolized by the 5-alpha reductase enzyme. This metabolism will reduce Boldenone to an extremely potent androgen in dihydroboldenone, far more potent than dihydrotestosterone (DHT); however, the total dihydroboldenone activity has proven to be extremely low in human beings. You will further find the androgenic nature of Boldenone will not be significantly affected by 5-alpha reductase inhibitors like Finasteride that are often used to combat the reduction to DHT.
Due to the androgenic nature of Equipoise, women may potentially experience virilization symptoms. Virilization symptoms may include body hair growth, a deepening of the vocal chords and clitoral enlargement. However, the low androgenicity will make this steroid possible to use for some women without such symptoms. At the same time, the extremely slow acting nature of the compound can make it difficult to control regarding blood levels, and alternative steroids may be preferred. Without question, individual sensitivity will dictate a lot. If Equipoise is used and virilization symptoms begin to show, use should be discontinued immediately at their onset and they will fade away. If symptoms begin to show and are ignored, the symptoms may become irreversible.
Sex hormone-binding globulin (SHBG) is thought to mainly function as a transporter and reservoir for the estradiol and testosterone sex hormones. However it has also been demonstrated that SHBG can bind to a cell surface receptor (SHBG-R). The SHBG-R has not been completely characterized. A subset of steroids are able to bind to the SHBG/SHBG-R complex resulting in an activation of adenylyl cyclase and synthesis of the cAMP second messenger.  Hence the SHBG/SHBG-R complex appears to act as a transmembrane steroid receptor that is capable of transmitting signals to the interior of cells.