CALUSTERONE is a 17-alkylated androgenic steroid. It may alter the metabolism of estradiol and reduce estrogen production. As an androgen, CALUSTERONE was used as a therapeutic agent in postmenopausal women with metastatic breast cancer.

Calusterone:
https://drugs.ncats.io/drug/0678G6Q58A

Methosarb, a.k.a. calusterone, is a uniquely modified version of testosterone with dual alterations. It possesses one added methyl group at carbon 7-beta which essentially deactivates its anabolic and androgenic effects, and another one at carbon 17-alpha which permits it to pass through the liver undisturbed.

Methosarb was developed as a less (near non-toxic) alternative to traditional anabolic steroids for the treatment of inoperable and metastatic breast cancer in both men and postmenopausal women.

This steroid came in 50 mg tablets, but is no longer manufactured as a prescription medication.

This extremely unique drug, barely even warrants being described as an anabolic steroid or androgen. Its substantial alteration at carbon 7-beta, renders it virtually ineffectual for anabolic and performance enhancement purposes. It is therefore not recommended for such uses, even as a supporting anabolic cycle ingredient with legendary anabolic compounds like Dianabol, Deca-Durabolin, Trenbolone, testoserone.This extremely unique drug, barely even warrants being described as an anabolic steroid or androgen. Its substantial alteration at carbon 7-beta, renders it virtually ineffectual for anabolic and performance enhancement purposes. It is therefore not recommended for such uses, even as a supporting anabolic cycle ingredient with legendary anabolic compounds like Dianabol, Deca-Durabolin, Trenbolone, Testoserone.

Excerpt from steroid.com:
https://www.steroid.com/Methosarb.php

Calusterone is an androgenic steroid. Calusterone may alter the metabolism of estradiol and reduce estrogen production.

Calusterone given orally induce a marked decrease (between 30 and 70% depending on the dose) in the binding capacity of oestradiol-17beta to specific uterine receptors in vivo. As an androgen, calusterone has been used as a therapeutic agent in postmenopausal women with metastatic breast cancer; the addition of a potent hormonal agent to effective cytotoxic chemotherapy improves the results of treatment of women with metastatic breast cancer. Calusterone is tested in sport screening;

belongs to the class of organic compounds known as androgens and derivatives. These are 3-hydroxylated C19 steroid hormones. They are known to favor the development of masculine characteristics. They also show profound effects on scalp and body hair in humans.

Excerpt from hmdb.ca:
http://www.hmdb.ca/metabolites/HMDB0004627

Calusterone:

• An orally active anabolic-androgenic steroid
• Used as an antineoplastic agent
• Similar in structure to bolasterone

Calusterone is on the World Anti-Doping Agency's list of prohibited substances