Anabolic steroidAndrogenInjectableOral17-alkylatedMethandienone derivative

Formebolone (Esiclene)

Also known as Formyldienolone · Esiclene · Hubernol · Metanor

Written by enwyReviewed 5 Aug 20261 sources0 comments

Formyldienolone, a methandienone-derived steroid marketed in Italy and Spain (Esiclene, Hubernol). Injected locally by bodybuilders to create short-term muscle swelling for stage cosmetics rather than for real mass, because it induces local inflammation.

01 Overview

Formebolone (2-formyl-11α-hydroxy-17α-methyl-δ1-testosterone) is an orally active AAS first produced in Italy in 1969 and used clinically for childhood growth deficiency and malnutrition. It is structurally a methandienone (Dianabol) derivative.

Its notoriety in bodybuilding comes from the injectable Esiclene: injected into small muscles (biceps, calves, delts) shortly before a contest, it produces localised inflammation and temporary swelling, cosmetically "filling out" lagging muscle groups. It builds little genuine muscle, so it is a niche pre-contest cosmetic agent rather than a true anabolic.

02 Mechanism

Androgen receptor agonist derived from methandienone; the injectable form additionally causes a local inflammatory reaction at the injection site, producing transient swelling independent of true hypertrophy.

03 Dosing

Tier	Dose	Route	Notes
Historical	5–20 mg/day	Oral	Former clinical oral dosing.
Local cosmetic	25–50 mg	IM	Injected into target muscle pre-contest; effect is swelling, not growth.

Ester comparison

Ester	Half-life	Injection freq.	Testosterone by mass

04 Effects

Effect	Magnitude	Evidence
Localised muscle swellingLocal injection swells the target muscle for days via inflammation; prized for stage presentation.	Temporary, cosmetic	Anecdotal
Mild systemic anabolismWeak true muscle-building relative to its cosmetic use.	Low	Preclinical

05 Side effects

Effect	Severity	Frequency	Evidence	Countermeasures
Injection-site pain and inflammationThe swelling mechanism is itself painful local inflammation; some formulations included a local anaesthetic.	Moderate	Very common	Anecdotal
Hepatotoxicity17α-alkylated structure carries oral-steroid liver risk.	Moderate	Common	Preclinical

06 Legal status

United States

Schedule III controlled

as of Jan 2026

WADA S1 anabolic agent

as of Jan 2026

07 References

FormeboloneWikipedia / CAS 2454-11-7 monograph

08 Discussion0 comments

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This page is reference information, not medical advice. Doses and protocols are documented as they appear in the clinical literature and in practice — describing them is not a recommendation to use them. Countermeasures listed here are not a substitute for a physician. Legal status varies by jurisdiction and changes.