Trenbolone

Not to be confused with Trestolone.

Trenbolone is an androgen and anabolic steroid (AAS) of the nandrolone group which itself was never marketed.^{[clarification needed][2][3][4][5][6]} Trenbolone ester prodrugs, including trenbolone acetate (brand names Finajet, Finaplix, others) and trenbolone hexahydrobenzylcarbonate (brand names Parabolan, Hexabolan), are or have been marketed for veterinary and clinical use.^{[2][3][4][6][7][8]} Trenbolone acetate is used in veterinary medicine in livestock to increase muscle growth and appetite, while trenbolone hexahydrobenzylcarbonate was formerly used clinically in humans but is now no longer marketed.^[2][3][4][6] In addition, although it is not approved for clinical or veterinary use, trenbolone enanthate is sometimes sold on the black market under the nickname Trenabol.^[6]

A vial of injectable trenbolone acetate.

Trenbolone

Clinical data
Other names	Trienolone; Trienbolone; RU-2341; Δ9,11-Nandrolone; 19-Nor-δ9,11-testosterone; Estra-4,9,11-trien-17β-ol-3-one
AHFS/Drugs.com	International Drug Names
License data	US DailyMed: Trenbolone
Pregnancy category	X
Routes of administration	Intramuscular injection (as esters)
Drug class	Androgen; Anabolic steroid; Progestogen
ATC code	None
Legal status
Legal status	BR: Class C5 (Anabolic steroids)[1] CA: Schedule IV US: Schedule III
Pharmacokinetic data
Bioavailability	Intramuscular: 80-100%[citation needed]
Metabolism	Liver
Elimination half-life	6–8 hours[citation needed]
Excretion	Urine
Identifiers
IUPAC name (8S,13S,14S,17S)-17-Hydroxy-13-methyl-2,6,7,8,14,15,16,17-octahydro-1H-cyclopenta[a]phenanthren-3-one
CAS Number	10161-33-8 N
PubChem CID	25015
DrugBank	DB11551 Y
ChemSpider	23383 Y
UNII	P53R4420TR
KEGG	D08627
ChEBI	CHEBI:35018
ChEMBL	ChEMBL3182355
CompTox Dashboard (EPA)	DTXSID0034192
ECHA InfoCard	100.127.177
Chemical and physical data
Formula	C18H22O2
Molar mass	270.372 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C4\C=C2/C(=C1/C=C\[C@@]3([C@@H](O)CC[C@H]3[C@@H]1CC2)C)CC4
InChI InChI=1S/C18H22O2/c1-18-9-8-14-13-5-3-12(19)10-11(13)2-4-15(14)16(18)6-7-17(18)20/h8-10,15-17,20H,2-7H2,1H3/t15-,16+,17+,18+/m1/s1 Y Key:MEHHPFQKXOUFFV-OWSLCNJRSA-N Y
NY (what is this?)  (verify)

Uses

Veterinary

Trenbolone, as trenbolone acetate, improves muscle mass, feed efficiency, and mineral absorption in cattle.^[6]

Side effects

See also: Anabolic steroid § Adverse effects

Sometimes human users may experience an event called "tren cough" shortly after or during an injection, where the user experiences a violent and extreme coughing fit, which can last for minutes and in some cases even longer.

"Tren cough", despite its name, is not exclusive to trenbolone. It can occur when injecting any oil-steroid solutions, if the solution accidentally is injected intravenously. When the oil-steroid solution gets into the bloodstream, the steroid oil solution travels into the lungs, therefore causing a coughing fit. There exist several theories on why this phenomenon happens.^[9]

It is possible that the androgenic effect from steroids activates a variety of lipid-like active compounds which are called prostaglandins.^[10] Many of these prostaglandins are inflammatory and vasoconstrictive. Prostaglandins are signalled through two varying pathways cyclooxygenase (COX) (Also known as: prostaglandin-endoperoxide synthase) and lipoxygenases (LOX) (also known as: EC 1.13.11.34, EC 1.13.11.33, etc.).^[11] The bradykinin peptide is well known to promote a cough reaction associated with ACE inhibitor medications prescribed for hypertension.^[12]

Pharmacology

Pharmacodynamics

Trenbolone has both anabolic and androgenic effects.^[6] Once metabolized, trenbolone esters have the effect of increasing ammonium ion uptake by muscles, leading to an increase in the rate of protein synthesis. It may also have the secondary effects of stimulating appetite and decreasing the rate of catabolism, as all anabolic steroids are believed to; however, catabolism likely increases significantly once the steroid is no longer taken.^[13] At least one study in rats has shown trenbolone to cause gene expression of the androgen receptor (AR) at least as potent as dihydrotestosterone (DHT). This evidence tends to indicate trenbolone can cause an increase in male secondary sex characteristics without the need to convert to a more potent androgen in the body.^[14]

Studies on metabolism are mixed, with some studies showing that it is metabolized by aromatase or 5α-reductase into estrogenic compounds, or into 5α-reduced androgenic compounds, respectively.^[15][16]

The potency of Trenbolone is not known, although it's often falsely believed to be five times high as that of testosterone.^[17][18] This is based on a book by William Llewellyn but has not been definitively proven. Trenbolone was never approved for human use, and therefore limited data on the subject exists. The relevant literature, is usually done in rats, which makes the 500/100 potency number inaccurate. Rats respond differently to androgens and are less sensitive to androgens. While some literature report a 5 fold higher potency, two other scientific reviews report a 3 fold higher potency, which makes it unclear as to how large the relative potency actually is.^[19][20] Trenbolone also binds with high affinity to the progesterone receptor,^{[6][21][22][23]} and binds to the glucocorticoid receptor as well.^[22]

Pharmacokinetics

To prolong its elimination half-life, trenbolone is administered as a prodrug as an ester conjugate such as trenbolone acetate, trenbolone enanthate, or trenbolone hexahydrobenzylcarbonate.^[2][3][4][6] Plasma lipases then cleave the ester group in the bloodstream leaving free trenbolone.^{[citation needed]}

Trenbolone and 17-epitrenbolone are both excreted in urine as conjugates that can be hydrolyzed with beta-glucuronidase.^[24] This implies that trenbolone leaves the body as beta-glucuronides or sulfates.

Chemistry

See also: List of androgens/anabolic steroids

Trenbolone, also known as 19-nor-δ^9,11-testosterone or as estra-4,9,11-trien-17β-ol-3-one, is a synthetic estrane steroid and a derivative of nandrolone (19-nortestosterone).^[2][3][6] It is specifically nandrolone with two additional double bonds in the steroid nucleus.^[2][3][6] Trenbolone esters, which have an ester at the C17β position, include trenbolone acetate, trenbolone enanthate, trenbolone hexahydrobenzylcarbonate, and trenbolone undecanoate.^{[2][3][6][25]}

Basic information about different types steroids included base trenbolone inside structure.

Name:	Trenbolone	Trenbolone acetate	Trenbolone enanthate	Trenbolone hexahydrobenzylcarbonate (cyclohexylmethylcarbonate)
Structural[25]
Formula	C18H22O2	C20H24O3	C25H34O3	C26H34O4
Crystal system[25]		monocrystalic	monocrystalic	monocrystalic
Elimination half life	48–72 hours[citation needed]	short 1–2 days;[25] 3 days[26]	long 11 days[25]	8 days[25]

History

Trenbolone was first synthesized in 1963.^[27]

Society and culture

Generic names

Trenbolone is the generic name of the drug and its INNTooltip International Nonproprietary Name and BANTooltip British Approved Name.^[2][3][4] It has also been referred to as trienolone or trienbolone or tren.^{[2][3][4][28]}

Legal status

Some bodybuilders and athletes use trenbolone hexahydrobenzylcarbonate and other esters (acetate, enanthate) for their muscle-building and otherwise performance-enhancing effects.^[29][6] Such use is illegal in the United States and several European and Asian countries. The DEA classifies trenbolone and its esters as Schedule III controlled substances under the Controlled Substances Act.^[30] Trenbolone is classified as a Schedule 4 drug in Canada^[31] and a class C drug with no penalty for personal use or possession in the United Kingdom.^[32] Use or possession of steroids without a prescription is a crime in Australia.^[33]

Doping in sports

See also: List of doping in sport cases § Trenbolone esters

There are known cases of doping in sports with trenbolone esters by professional athletes.

See also

• Metribolone

References

1. Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-15.
2. Elks J (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. ISBN 978-1-4757-2085-3. Archived from the original on 11 January 2023. Retrieved 11 November 2017.
3. Index Nominum 2000: International Drug Directory. Taylor & Francis. January 2000. p. 1591. ISBN 978-3-88763-075-1.
4. Morton IK, Hall JM (6 December 2012). Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer Science & Business Media. pp. 279–. ISBN 978-94-011-4439-1. Archived from the original on 11 January 2023. Retrieved 11 November 2017.
5. "Trenbolone". Archived from the original on 2020-07-07. Retrieved 2017-11-11.
6. Llewellyn W (2011). Anabolics. Molecular Nutrition Llc. pp. 491–499, 618–, 724–. ISBN 978-0-9828280-1-4.
7. Nichols W, Hutcheson J, Streeter M, Corrigan M, Nuttelman B. "Implant Strategies for Finishing Cattle using Revalor® (trenbolone acetate and estradiol), Finaplix® (trenbolone) and/or Ralgro® (zeranol)" (PDF). Merck Animal Health. Archived (PDF) from the original on 2012-10-13. Retrieved 2011-08-22.
8. Kicman AT (June 2008). "Pharmacology of anabolic steroids". British Journal of Pharmacology. 154 (3): 502–521. doi:10.1038/bjp.2008.165. PMC 2439524. PMID 18500378.
9. Russell M, Storck A, Ainslie M (2011). "Acute respiratory distress following intravenous injection of an oil-steroid solution". Canadian Respiratory Journal. 18 (4): e59–e61. doi:10.1155/2011/743151. PMC 3205107. PMID 22059184.
10. Notelovitz M (April 2002). "Androgen effects on bone and muscle". Fertility and Sterility. 77 (Suppl 4): S34–S41. doi:10.1016/s0015-0282(02)02968-0. PMID 12007900.
11. Kam PC, See AU (May 2000). "Cyclo-oxygenase isoenzymes: physiological and pharmacological role". Anaesthesia. 55 (5): 442–449. doi:10.1046/j.1365-2044.2000.01271.x. PMID 10792135.
12. Fox AJ, Lalloo UG, Belvisi MG, Bernareggi M, Chung KF, Barnes PJ (July 1996). "Bradykinin-evoked sensitization of airway sensory nerves: a mechanism for ACE-inhibitor cough". Nature Medicine. 2 (7): 814–817. doi:10.1038/nm0796-814. PMID 8673930.
13. Fahey TD (March 1998). "Anabolic Steroids: Mechanisms and Effects". Encyclopedia of sports medicine and science. Internet Society for Sport Science. Archived from the original on 2011-08-23. Retrieved 2011-08-23.
14. Wilson VS, Lambright C, Ostby J, Gray LE (December 2002). "In vitro and in vivo effects of 17beta-trenbolone: a feedlot effluent contaminant". Toxicological Sciences. 70 (2): 202–211. doi:10.1093/toxsci/70.2.202. PMID 12441365.
15. Yarrow JF, McCoy SC, Borst SE (June 2010). "Tissue selectivity and potential clinical applications of trenbolone (17beta-hydroxyestra-4,9,11-trien-3-one): A potent anabolic steroid with reduced androgenic and estrogenic activity". Steroids. 75 (6): 377–389. doi:10.1016/j.steroids.2010.01.019. PMID 20138077. S2CID 205253265.
16. Gettys TW, D'Occhio MJ, Henricks DM, Schanbacher BD (January 1984). "Suppression of LH secretion by oestradiol, dihydrotestosterone and trenbolone acetate in the acutely castrated bull". The Journal of Endocrinology. 100 (1): 107–112. doi:10.1677/joe.0.1000107. PMID 6361192.
17. Llewellyn W (2011). Anabolics. Molecular Nutrition Llc. ISBN 978-0-9828280-1-4.
18. Wiebe JP (2011-01-13). "The microenvironment in health and cancer of the mammary gland". In Mascie-Taylor CG, Rosetta L (eds.). Reproduction and Adaptation: Topics in Human Reproductive Ecology. Cambridge University Press. p. 69. ISBN 978-1-139-49430-4.
19. Neumann F (1976). "Pharmacological and endocrinological studies on anabolic agents". Environmental Quality and Safety. Supplement (5): 253–264. PMID 782871.
20. Yarrow JF, McCoy SC, Borst SE (June 2010). "Tissue selectivity and potential clinical applications of trenbolone (17beta-hydroxyestra-4,9,11-trien-3-one): A potent anabolic steroid with reduced androgenic and estrogenic activity". Steroids. 75 (6): 377–389. doi:10.1016/j.steroids.2010.01.019. PMID 20138077.
21. Nicholas Mascie-Taylor CG, Rosetta L (13 January 2011). Reproduction and Adaptation: Topics in Human Reproductive Ecology. Cambridge University Press. pp. 69–. ISBN 978-1-139-49430-4.
22. APMIS.: Supplementum. Munksgaard. 2001. p. 5339. ISBN 9788716164575.
23. McKerns KW (13 March 2013). Reproductive Processes and Contraception. Springer Science & Business Media. pp. 171–. ISBN 978-1-4684-3824-6.
24. Schänzer W (July 1996). "Metabolism of anabolic androgenic steroids". Clinical Chemistry. 42 (7): 1001–1020. doi:10.1093/clinchem/42.7.1001. PMID 8674183.
25. Borodi G, Turza A, Camarasan PA, Ulici A (2020). "Structural studies of Trenbolone, Trenbolone Acetate, Hexahydrobenzylcarbonate and Enanthate esters". Journal of Molecular Structure. 1212: 128127. Bibcode:2020JMoSt121228127B. doi:10.1016/j.molstruc.2020.128127. ISSN 0022-2860. S2CID 216299984.
26. Ruiz P, Strain EC (2011). Lowinson and Ruiz's Substance Abuse: A Comprehensive Textbook. Lippincott Williams & Wilkins. ISBN 978-1-60547-277-5.
27. Schänzer W (July 1996). "Metabolism of anabolic androgenic steroids". Clinical Chemistry. 42 (7): 1001–1020. doi:10.1093/clinchem/42.7.1001. PMID 8674183.
28. Food and Agriculture Organization of the United Nations (1990). Residues of Some Veterinary Drugs in Animals and Foods: Monographs Prepared by the Thirty-Fourth Meeting of the Joint FAO/WHO Expert Committee on Food Additives, Geneva, 30 January-8 February 1989. Food & Agriculture Org. pp. 88–. ISBN 978-92-5-102933-6.
29. "Trenbolone hexahydrobenzylcarbonate use in bodybuilding". 20 November 2021. Archived from the original on 24 November 2021. Retrieved 24 November 2021.
30. "Controlled Substances Act". United States Food and Drug Administration. 11 June 2009. Archived from the original on 2 March 2017. Retrieved 17 June 2016.
31. "Controlled Drugs and Substances Act". laws-lois.justice.gc.ca. Archived from the original on 2012-09-15.
32. "Consideration of the Anabolic Steroids". London: Advisory Council on the Misuse of Drugs. September 2010. Archived from the original on 2011-09-22.
33. "Australian Institute of Criminology - Steroids". Archived from the original on 2012-03-23. Retrieved 2011-08-22.

Further reading

• Meyer HH (January 2001). "Biochemistry and physiology of anabolic hormones used for improvement of meat production". APMIS. 109 (1): 1–8. doi:10.1111/j.1600-0463.2001.tb05785.x. PMID 11297191. S2CID 23149070.
• Yarrow JF, McCoy SC, Borst SE (June 2010). "Tissue selectivity and potential clinical applications of trenbolone (17beta-hydroxyestra-4,9,11-trien-3-one): A potent anabolic steroid with reduced androgenic and estrogenic activity". Steroids. 75 (6): 377–389. doi:10.1016/j.steroids.2010.01.019. PMID 20138077. S2CID 205253265.