Trimethyltrienolone (TMT), also known by its developmental code name R-2956 or RU-2956, is an

antiandrogen Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking t ...

medication which was never introduced for medical use but has been used in

scientific research The scientific method is an empirical method for acquiring knowledge that has been referred to while doing science since at least the 17th century. Historically, it was developed through the centuries from the ancient and medieval world. The ...

Side effects

Due to its close relation to metribolone (methyltrienolone), it is thought that TMT may produce

hepatotoxicity Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury (DILI) is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdr ...

Pharmacology

Pharmacodynamics

TMT is a selective and highly potent

competitive Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

antagonist An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.androgen receptor The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...

(AR) with very low

intrinsic In science and engineering, an intrinsic property is a property of a specified subject that exists itself or within the subject. An extrinsic property is not essential or inherent to the subject that is being characterized. For example, mass i ...

partial Partial may refer to: Mathematics *Partial derivative, derivative with respect to one of several variables of a function, with the other variables held constant ** ∂, a symbol that can denote a partial derivative, sometimes pronounced "partial d ...

androgen An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...

ic activity and no

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

ic, antiestrogenic,

progestogen Progestogens, also sometimes written progestins, progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestoge ...

ic, or antimineralocorticoid activity. The drug is a

derivative In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...

of the extremely potent

anabolic steroid Anabolic steroids, also known as anabolic-androgenic steroids (AAS), are a class of drugs that are structurally related to testosterone, the main male sex hormone, and produce effects by binding to the androgen receptor (AR). Anabolism, Anaboli ...

metribolone (R-1881; 17α-methyltrenbolone), and has been reported to possess only about 4-fold lower

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Pa ...

for the AR in comparison. In accordance, it has relatively high affinity for the AR among steroidal antiandrogens, and almost completely inhibits

dihydrotestosterone Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone primarily involved in the growth and repair of the prostate and the penis, as well as the production o ...

(DHT) binding to the AR ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'' at a mere 10-fold molar excess. The AR weak partial agonistic activity of TMT is comparable to that of

cyproterone acetate Cyproterone acetate (CPA), sold alone under the brand name Androcur or Ethinylestradiol/cyproterone acetate, with ethinylestradiol under the brand names Diane or Diane-35 among others, is an antiandrogen and progestin medication used in the tre ...

Chemistry

TMT, also known as 2α,2β,17α-trimethyltrienolone or as δ^9,11-2α,2β,17α-trimethyl-19-nortestosterone, as well as 2α,2β,17α-trimethylestra-4,9,11-trien-17β-ol-3-one, is a

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

estrane

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

and a

testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...

and 19-nortestosterone. It is the 2α,2β,17α-trimethyl derivative of

trenbolone Trenbolone is an androgen and anabolic steroid (AAS) of the nandrolone group which itself was never marketed. Trenbolone ester prodrugs, including trenbolone acetate (brand names Finajet, Finaplix, others) and trenbolone hexahydrobenzylcarbonat ...

(trienolone) and the 2α,2β-dimethyl derivative of metribolone (methyltrienolone), both of which are synthetic

History

TMT was developed by Roussel Uclaf in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

and was first known as early as 1969. It was one of the earliest antiandrogens to be discovered and developed, along with others such as benorterone, BOMT, cyproterone, and

. The drug was under investigation by Roussel Uclaf for potential medical use, but was abandoned in favor of

nonsteroidal antiandrogen A nonsteroidal antiandrogen (NSAA) is an antiandrogen with a nonsteroidal chemical structure. They are typically selective and full or silent antagonists of the androgen receptor (AR) and act by directly blocking the effects of androgens lik ...

s like flutamide and nilutamide due to their comparative advantage of a complete lack of androgenicity. Roussel Uclaf subsequently developed and introduced nilutamide for medical use.

References

{{Androgen receptor modulators Abandoned drugs Tertiary alcohols Estranes Hepatotoxins Ketones Steroidal antiandrogens