4-Chlorodehydromethyltestosterone
4-Chlorodehydromethyltestosterone, sold under the brand name Turinabol, is an anabolic steroid developed in the 1960s, a highly competitive time for the Olympics and national level sports, the East German experts were looking for effective steroids that would circumvent these sports drug testing policies.  What they settled on was the methylated version of 4-chorotestosterone, also called Oral Turinabol.  Oral Turinabol is often described as having properties somewhere between Dianabol, and Anavar. With its moderate anabolic effects, and mild-ish side effects, this isn't a bad description.  The androgenic effect of Turinabol is said to be between 0 to 6 and the anabolic effect is 53.
Because of this slower rate of gain, people who take Turinabol should not expect weight, strength or muscle mass to increase dramatically, but the muscle and strength they do gain will be a quality gain.  People report that Turinabol gives a nice hard look because it lacks the estrogenic properties which can lead to an undesirable puffy look.
One of the other benefits of Turinabol stems from why the East Germans were able to use it undetected for a while: The body quickly breaks it down and excretes it which might make it beneficial for those who will be undergoing drug screening.
Because of the 4-chloro alteration, Oral Turinabol can't interact with the aromatase enzyme, so estrogenic side effects aren't really a concern.  However, it is interesting to note that some users report mild gynocomastia with oral turinabol alone. Whether this is due to the aromatization of a small amount of methyltestosterone left over from the manufacturing process, the effect of androgens on electrolyte balance, or Oral Turinabol possibly having a small amount of direct action at the estrogen receptor, is unclear.  The 4-chloro alteration also prevents Oral Turinabol from interacting with the 5-alpha reductase enzyme, so conversion to a dihydro form is not possible. Even so, androgenic allopecia is still possible with higher doses eg (>40mg/day), and not surprisingly, some erectile dysfunction will be present when Oral Turinabol is used alone dispite a functional, or highly functional sex drive.  Although mild acne, gas, indigestion, elevated liver enzymes, diminished production of leutinizing hormone, and natural testosterone, are all worth noting, the most serious concern is the effect it has on  the blood lipid profile.
Regardless of dosage amounts and length of regimens, Turinabol has one characteristic that should give caution to all of its users:  It is 17-alpha alkylated which makes it hepatoxic because I can't be easily broken down in the liver.  Although some studies show liver enzymes to stay within normal ranges on a dose of ten milligrams per day, people using Oral Turinabol should keep usage limited to about six weeks to avoid liver damage.  Additionally, Turinabol can lower the bloods ability to clot, so special caution should be taken when using this steroid.
While Oral Turnibol has its pros and cons, it does produce quality gains in muscle mass as well as strength, even if these gains are not as dramatic or quick as you might get from an aromatizable, or more androgenic oral steroid.

# Further reading
Roberts, Anthony (January 2006). Anabolic Steroids: Ultimate Research Guide. Anabolic Books, LLC. p. 394. ISBN 1-59975-100-3..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
Daniels, R. C. (February 1, 2003). The Anabolic Steroid Handbook. Richard C Daniels. p. 80. ISBN 0-9548227-0-6.
Roberts, Anthony (May 2006). Beyond Steroids. EF Publishing Inc. p. 250.