Formebolone (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

, BAN) (brand names Esiclene, Hubernol, Metanor), also known as formyldienolone, as well as 2-formyl-11α-hydroxy-17α-methyl-δ¹-testosterone, is an orally active

anabolic-androgenic steroid Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone (medication), testosterone as well as synthetic androgens that are structurally related ...

(AAS) described as an anticatabolic and

anabolic Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-do ...

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...

that is or has been marketed in

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

and

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

. As an AAS, it shows some anabolic activity, though it is inferior to

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

in terms of

potency Potency may refer to: * Potency (pharmacology), a measure of the activity of a drug in a biological system * Virility * Cell potency, a measure of the differentiation potential of stem cells * In homeopathic dilutions, potency is a measure of how ...

, but is said to have virtually no

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

ic activity. Formebolone counteracts the

catabolic Catabolism () is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions. Catabolism breaks down large molecules (such as polysaccharides, lipids, ...

effects (control of

nitrogen balance Nitrogen balance is a measure of nitrogen input minus nitrogen output. Nitrogen Balance = Nitrogen intake - Nitrogen loss Sources of nitrogen intake include meat, fish, dairy foods, eggs, nuts and legumes, and grains and cereals. Examples of nitr ...

) of potent

glucocorticoid Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every vertebr ...

s like

dexamethasone phosphate Dexamethasone is a glucocorticoid medication used to treat rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive lung disease, croup, brain swelling, eye pain following eye surgery, superior vena cava s ...

. A close analogue,

roxibolone Roxibolone (INN) (developmental code name BR-906), also known as 11β,17β-dihydroxy-17α-methyl-3-oxoandrosta-1,4-diene-2-carboxylic acid, is a steroidal antiglucocorticoid described as an anticholesterolemic (cholesterol-lowering) and anabolic ...

(and its long-acting

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

variant decylroxibolone), shows similar antiglucocorticoid activity to formebolone but, in contrast, is devoid of activity as an AAS. Roxibolone has been found not to bind to the

glucocorticoid receptor The glucocorticoid receptor (GR, or GCR) also known as NR3C1 (nuclear receptor subfamily 3, group C, member 1) is the receptor to which cortisol and other glucocorticoids bind. The GR is expressed in almost every cell in the body and regulates ...

, and it has been suggested that the antiglucocorticoid activity of roxibolone and formebolone may instead be mediated by

modulation In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the ''carrier signal'', with a separate signal called the ''modulation signal'' that typically contains informatio ...

enzymatic Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

processes. Indeed, 11α- and

11β-hydroxyprogesterone 11β-Hydroxyprogesterone (11β-OHP), also known as 21-deoxycorticosterone, as well as 11β-hydroxypregn-4-ene-3,20-dione, is a naturally occurring, endogenous steroid and derivative of progesterone. It is a potent mineralocorticoid. Syntheses of 1 ...

(formebolone and roxibolone being 11α- and 11β-hydroxylated (respectively) similarly) are known to be potent

inhibitor Inhibitor or inhibition may refer to: In biology * Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity * Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotra ...

s of 11β-hydroxysteroid dehydrogenase (11β-HSD), which is responsible for the

biosynthesis Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...

of the potent

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...

glucocorticoids

cortisol Cortisol is a steroid hormone, in the glucocorticoid class of hormones. When used as a medication, it is known as hydrocortisone. It is produced in many animals, mainly by the ''zona fasciculata'' of the adrenal cortex in the adrenal gland ...

and

corticosterone Corticosterone, also known as 17-deoxycortisol and 11β,21-dihydroxyprogesterone, is a 21-carbon steroid hormone of the corticosteroid type produced in the cortex of the adrenal glands. It is of minor importance in humans, except in the very rare ...

(from the

precursor Precursor or Precursors may refer to: *Precursor (religion), a forerunner, predecessor ** The Precursor, John the Baptist Science and technology * Precursor (bird), a hypothesized genus of fossil birds that was composed of fossilized parts of unr ...

deoxycortisol Deoxycortisol may refer to: * 11-Deoxycortisol (cortodoxone, cortexolone, Reichstein's Substance; 17α,21-dihydroxyprogesterone) * 17-Deoxycortisol (corticosterone; 11β,21-dihydroxyprogesterone) * 21-Deoxycortisol (11β,17α-dihydroxyprogestero ...

and

deoxycorticosterone Deoxycorticosterone (DOC), or desoxycorticosterone, may refer to: * 11-Deoxycorticosterone (21-hydroxyprogesterone) * 21-Deoxycorticosterone (11β-hydroxyprogesterone) See also * Deoxycortisol * Deoxycortisone * 11-Hydroxyprogesterone {{Che ...

, respectively). However, formebolone was found to be a very weak inhibitor of 11β-HSD type 2 ( IC₅₀ > 10 μM), although this specific

isoenzyme In biochemistry, isozymes (also known as isoenzymes or more generally as multiple forms of enzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. Isozymes usually have different kinetic parameters (e.g. dif ...

of 11β-HSD is responsible for the inactivation of glucocorticoids rather than their production.

References

{{Androgen receptor modulators Antiglucocorticoids Androgens and anabolic steroids Androstanes Conjugated aldehydes Diols Hepatotoxins Enones World Anti-Doping Agency prohibited substances