The next addition to the “strange steroids” series focuses on a couple of steroids possessing anabolic and/or androgenic activity despite the lack of a 17b-hydroxyl function.
The 17b-hydroxyl group is the most fundamental commonality between steroids that attach to and activate the androgen receptor, with all commercialised anabolic steroids either containing, or being metabolized to, a steroid that contains a 17b-OH.
“Without any doubt, the attachment of the steroid to the receptor at the 17-hydroxyl group is one of the most important attachments. The presence of oxygen in the form of a 17b-hydroxyl group is more important than the presence of oxygen at carbon-3 and for practical purposes all useful anabolic agents and highly active androgens possess the 17b-hydroxyl group.” 
The key to the significance of this function is hydrogen bonding, an important feature in ligand-receptor interactions. The Asn705 and Thr877 residues of the androgen receptor form hydrogen bonds with the 17β hydroxyl, locking the steroid into the ligand binding pocket of the receptor.  Modification or elimination of the 17β hydroxyl typically ablates anabolic and androgenic action, but not in every case.