Ethylestrenol (INN, USAN, BAN) (brand names Maxibolin, Orabolin), or ethylnandrol (JAN), is an anabolic-androgenic steroid (AAS) with some progestogenic activity, and low androgenic activity. It is a derivative of nandrolone and lacks the 3-keto group. It was described in the literature in 1959 and approved in 1964 for testosterone deficiency in male patients.

Ethylestrenol:
https://drugs.ncats.io/drug/ADC79EK5Q8

The Chemical name of Orabolin is Ethylestrenol
What we'e looking at with Orabolin is yet another steroid that has been off the market for so long that I haven't been able to actually find someone who's used it. Orabolin is a 19Nor-steroid, meaning it's been derived from nandrolone. We know that 19nor compounds all bind well to the androgen receptor, and that this is part of the reason that Orabolin imparts such a strong anabolic effect. Orabolin has very good androgen binding properties, giving it good enough anabolic effect, but is actually androgenically reduced in androgen responsive tissues like prostate and skin. Orabolin has such a distressingly broad anabolic/androgenic range. There is also a 17-alpha-ethyl group to contend with, and that gives this compound a degree of hepatoxicity that makes the cost/benefit ratio very poor for athletes, and thus it's rarely found on the black market. The weirdest thing about Orabolin is that it comes as some kind of bizarre paste for oral administration I really don't know why this stuff was ever brought to the market, but the fact that it comes as an oral paste is just very bizarre.

Ethylestrenol is an oral anabolic steroid derived from nandrolone. As is typical for many 19-nor steroids, this agent exhibits far greater anabolic properties than androgenic, is only weakly estrogenic, and is strongly progestational. Structurally, ethylestrenol most closely resembles Nilevar (norethandrolone). Although ethylestrenol is strongly anabolic relative to its androgenicity, athletes generally find this steroid to be extremely weak. The level of muscle growth obtained with this steroid is generally much less noticeable than that expected with either Nilevar or Deca-Durabolin, and it is considerably less effective than both stanozolol and oxandrolone on a milligram for milligram basis.

Ethylesterenol became a steroid of great controversy during the early 1980's, when Western media attention was given to the marketing of the drug to malnourished children in Third- World markets such as India, Bangladesh, and the Philippines. Advertising on Fertabolin in India claimed the drug would "help children gain full weight and height," "simulates physiological appetite," and "ensures optimal assimilation of food." It also described a "delicious [raspberry] syrup flavor children love." The main point of contention was the promotion of an anabolic steroid to treat the lack of adequate food supply, the real issue at hand. Many viewed Organon's actions as potentially dangerous and highly unethical, and the company soon discontinued Fertabolin and related marketing practices. Maxibolin and Maxibolin Elixir were voluntarily withdrawn from the U.S. market during the late 1980's as well, and most Western ethylestrenol products from Organon soon followed. Today, Merck/MSD retains only a limited interest in the drug. Ethylestrenol is currently a rare find, as it is only manufactured (as a generic drug or under other brand names) is a select few countries.

Pharmaceutical preparations containing ethylestrenol remain scarce. In reviewing some of the remaining products and changes in the global pharmaceutical market, we have made the following observations. At the present time, the legitimate supply of ethylestrenol appears to be isolated to Australia, where it is found in a small number of veterinary compounds including Nandora tablets and Nitrotain paste.

Durabolin-O is a compressed form of "Durabolin-Oral," noting that the drug is an oral cousin to Durabolin (nandrolone phenylpropionate).

/CASE REPORTS/ Forty-nine patients with decreased fibrinolytic activity in the vessel walls or a decreased release mechanism, or both, were treated with ethylestrenol for three to 17 months. Forty-five of the patients had had recurrent, phlebographically verified, deep venous thrombosis (DVT) and four had arterial thrombosis. Ethyloestrenol 8 mg/day was given to 31 patients and 4 mg/day was given to 12. The remaining six patients had been treated with a combination of phenformin and ethylestrenol. The phenformin was withdrawn but they were kept on ethylestrenol 8 mg/day. Another 15 patients with a normal fibrinolytic system - four with recurrent DVT and 11 with severe arteriosclerosis - were given ethylestrenol 8 mg/day. The spontaneous fibrinolytic activity, local fibrinolytic activity during standardized venous occlusion of the arms, and fibrinolytic activity of the vessel walls increased significantly after treatment with ethylestrenol 8 mg/day for three months. No further increase occurred after three months, and ethyloestrenol 4 mg/day had no effect. No values rose significantly in the patients with a normal fibrinolytic system. One patient suffered a recurrence within three months of treatment, before the fibrinolytic system became normal. In one patient the fibrinolytic defect reappeared after 10 months in spite of continued treatment. Two of the three women of fertile age developed irregular cycles and intermenstrual bleeding, which disappeared when the treatment was withdrawn. No other side effects were observed.

Ethylestrenol is or has been marketed under a variety of brand names including Durabolin O, Duraboral, Fertabolin, Maxibolin, Maxibolin Elixir, Orabolin, Orgabolin, Orgaboral, and Virastine. Durabolin-O is a compressed form of "Durabolin-Oral," noting that the drug is an oral cousin to Durabolin (nandrolone phenylpropionate). Ethylestrenol is or has also been marketed for veterinary use under the brand names Nandoral, Nitrotain, and Oestrotain. The availability of ethylestrenol is very limited. It appears to be available only in Australia and New Zealand and only for veterinary use.