This page describes pharmacological agents that may have legal restrictions, side effects, and drug interactions in your jurisdiction. Information is for educational research only — consult a clinician before considering any compound.

Hepatotoxicity warning

Fluoxymesterone is 17α-alkylated for oral bioavailability — a structural feature directly responsible for the most severe hepatotoxic class of AAS. Cholestatic injury, peliosis hepatis, and hepatic adenoma are all class-documented. Cycle length must be capped (typically < 6-8 weeks); LFTs (ALT, AST, GGT, bilirubin) baseline + every 2 weeks on cycle. Stop immediately on ALT/AST > 3× ULN or symptomatic jaundice.

High-risk compound

Surface here is educational only; do not use without medical supervision. Our editorial verdict is SKIP-PERMANENT — risk:benefit fails for the canonical archetype.

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Fluoxymesterone

Emerging

17α-methylated halogenated testosterone derivative — Upjohn-era oral AAS, used historically for combat-sport pre-fight aggression and…

Aliases (5)
Halotestin · Halo · Stenox · Ultandren · Fluoxymesteron
TYPICAL DOSE
Historical clinical (Upjohn label, hypogonadism…
Daily
ROUTE
Oral (tablet)
Oral
CYCLE
None
Cycle length (4-6 wk)
STORAGE
Room temp; original container
Room temp

Overview

What is Fluoxymesterone?

Fluoxymesterone (Halotestin) is a 17-alpha-alkylated synthetic androgen / anabolic steroid. Originally FDA-approved for hypogonadism, breast cancer, and delayed puberty; now rarely prescribed and primarily used in performance contexts.

Key Benefits

High androgenic potency for strength, aggression, and pre-competition cutting. Minimal aromatization and water retention. Used in powerlifting and bodybuilding briefly before competition. Significant hepatotoxicity limits use.

Mechanism of Action

Binds androgen receptors with high affinity. The 17-alpha-methyl group resists hepatic first-pass metabolism, allowing oral activity but causing hepatotoxicity. Does not aromatize to estrogen due to 11-beta-hydroxyl group.

Cycle structure & PCT AAS oral
Ester
enanthate
Frequency
biweekly
PCT
Required
Phase 1 — On cycle

Ramp dose over week 1, hold steady through cycle weeks. Track baseline labs (TT/FT/E2/SHBG/HCT/lipids/LFTs) at week 0; recheck at week 4 and end-of-cycle.

Phase 2 — Bridge / cease

On the last dose, the ester clears over its half-life window (enanthate = est. 7 days). PCT begins after the active compound has cleared.

Phase 3 — PCT (post-cycle therapy)

Standard PCT is enclomiphene 12.5-25 mg/day or clomid 50/50/25/25 over 4 weeks (or nolvadex 20/20/10/10). HCG bridge optional during cycle to preserve testicular volume + faster restart. Bloodwork at PCT week 4 + 8 to confirm HPG axis recovery (LH, FSH, TT back to baseline).

Research Protocols

Disclaimer: These are commonly discussed research protocols and not medical advice.

Goal:No microdose / cycled protocol that is meaningfully safer
Dose:
Frequency:
Solo:
Cycle:

Peptide Interactions

Other 17α-alkylated orals (methyltestosterone, oxandrolone, stanozolol, methandrostenolone):
Avoid

hepatotoxicity additive, often catastrophic.

Alcohol:
Avoid

hepatic stress additive — but a user in this archetype is zero-alcohol so n/a.

NSAIDs (chronic):
Avoid

hepatic + renal stress additive.

Other CNS stimulants at high dose (modafinil, amphetamines):
Avoid

insomnia + aggression amplified.

Quality Indicators

Pharmacy-dispensed, intact packaging

Prescription tablets in original sealed packaging from a licensed pharmacy.

!

Generic vs branded

Generics are usually fine but bioavailability can vary slightly; track if you switch.

Unbranded blister or counterfeit risk

Counterfeit pharmaceuticals are a known issue; verify pharmacy and lot if buying internationally.

What to Expect

  • Onset
    ~1-2 hr oral
  • Peak
    effects: 2-4 hr (halflife ~9.5 hr)

Side Effects & Safety

  • Common (>10% users):
    • HDL crash (often >40% reduction) and LDL/ApoB elevation
    • Acne (severe, often back/shoulder)
    • Aggression / irritability / short fuse
    • Insomnia
    • Headache
    • Elevated liver enzymes (ALT/AST/GGT) within first 2-4 weeks
    • HPG suppression (LH/FSH crash → low natural T)
    • Water retention (modest, less than aromatizing AAS)
  • Less common (1-10%):
    • Cholestatic jaundice (yellowing, dark urine, pale stool, pruritus)
    • Hypertension
    • Hematocrit/erythrocytosis elevation
    • Accelerated androgenic alopecia in genetically predisposed
    • Prostate symptoms (urinary changes)
    • Gynecomastia rare (no aromatization) but possible via prolactin pathway
  • Rare-serious (<1% but worth knowing):
    • Peliosis hepatis — blood-filled cystic lesions in the liver that can rupture catastrophically. 17α-AAS (halo, methyltest, stanozolol) are the primary pharmacologic causes. May persist after cessation.
    • Hepatocellular adenoma / hepatocellular carcinoma — documented with prolonged use of 17α-AAS; halo is among the highest-risk in the class.
    • Cardiovascular events — MI, stroke, cardiomyopathy; HDL crash + hypertension + erythrocytosis stack to elevate risk acutely on-cycle.
    • Severe psychiatric reactions — manic episodes, violent behavior, psychotic features in vulnerable users.
  • Specific watch periods: Liver enzymes within first 2 weeks; lipids within 3-4 weeks; any RUQ pain, jaundice, or unexplained fatigue is an emergency stop.
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