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Methenolone

Emerging

Mild DHT-derived AAS with a "clean" reputation — non-aromatizing, low androgenic, decent body comp. | AAS · Oil injectable

Aliases (5)
Primobolan · Primo · Methenolone Enanthate · Methenolone Acetate · Nibal
TYPICAL DOSE
300-700 mg
ROUTE
Intramuscular injection (oil)
CYCLE
8-12 weeks on
STORAGE
Room temp; protect from light
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Vial inspection & sterile draw AAS oil

AAS oil arrives pre-suspended in carrier oil — no BAC water needed. Inspect for clarity, color, and crashed compound (cold storage can crystallize). Warm vial in palm or under hot tap before draw.

Steps
  1. 1 Wipe vial stopper with isopropyl alcohol.
  2. 2 Warm vial 30-60s in palm if oil is cold/cloudy.
  3. 3 Draw with 18g needle into 22-25g pin barrel for IM, or 27-29g for sub-Q.
  4. 4 Tap out air bubbles, expel a small drop, then inject at chosen site.
Open dose calculator for Methenolone
Cycle structure & PCT AAS
Ester
enanthate
Cycle
10-12 week
Frequency
weekly
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).

Overview TL;DR

Mild DHT-derived AAS with a "clean" reputation — non-aromatizing, low androgenic, decent body comp. SKIP at 20: HPG axis still maturing, suppression risk is real, oral form is hepatotoxic, gray-market product is among the most counterfeited steroids in the world. Cost-per-real-mg often exceeds testosterone by 5-10×.

Mechanism of action

Methenolone is a 1-methylated derivative of dihydrotestosterone (DHT). Two relevant facts flow from this:

  1. DHT-derived → not a substrate for aromatase, so it cannot convert to estrogen. No gyno risk, no estrogenic water retention, no estradiol-driven HPG feedback (but androgen-driven HPG suppression still happens via central androgen receptor signaling).
  2. 1-methylation stabilizes the molecule against the 3α-HSD enzyme that normally inactivates DHT in muscle tissue, allowing meaningful AR activity in skeletal muscle (DHT itself is a weak muscle-builder despite being a strong androgen).

Two esters / forms:

  • Methenolone enanthate (injectable) — long ester, ~10 day half-life, weekly dosing, NOT C17α-alkylated → low hepatic burden.
  • Methenolone acetate (oral) — C17α-alkylated to survive first-pass metabolism → meaningful hepatotoxicity, low oral bioavailability (~30-40%), short half-life requires daily dosing.

Anabolic:androgenic ratio commonly cited as ~88:44-57 (vs testosterone 100:100), meaning roughly half the muscle-building potency of testosterone with reduced (not zero) androgenic side effects. As a DHT-derivative it can still drive androgenic hair pattern issues, prostate effects, and skin effects in susceptible users.

Pharmacokinetics No data
Pharmacokinetics data not available for this compound.
No half-life mentions found in the source notes.
Research indications2 use cases

Methenolone enanthate (injectable)

Most effective

long ester, ~10 day half-life, weekly dosing, NOT C17α-alkylated → low hepatic burden.

Methenolone acetate (oral)

Effective

C17α-alkylated to survive first-pass metabolism → meaningful hepatotoxicity, low oral bioavailability (~30-40%), short half-life requires…

Quality indicators5 checks
Clear oil
Yellow tint is normal (carrier oil); cloudiness or sediment is not.
No particulates
Hold the vial up to light. Floaters mean discard, not filter.
!
Color matches ester
Test E is light yellow; Tren A is amber. Off-color suggests under-dosing or wrong compound.
Sterile draw technique
Always swab vial top, fresh needle for draw, fresh needle for injection.
!
Crashed gear is recoverable
Holosteric carrier crashes when cold. Warm to body temp; if still cloudy, discard.
What to expect Generic
  1. 1
    Week 1-2
    Frontload phase. Strength gains start; appetite up.
  2. 2
    Week 3-4
    Visible muscle fullness and recovery acceleration.
  3. 3
    Week 5-8
    Peak performance window. Monitor blood pressure + libido.
  4. 4
    Post-cycle
    PCT week 1-4. Bloodwork at week 6 post-cycle.
Side effects + safety
  • Common (>10% users):
    • HPG axis suppression (always — "mild" suppression is still suppression). LH/FSH drop within weeks.
    • Reduced HDL, raised LDL/ApoB (DHT-class lipid impact, less severe than oral 17α-alkylated 19-nors but still meaningful).
    • Mild androgenic effects: skin (oily, acne-prone in susceptible users), accelerated androgenic alopecia in genetically predisposed users (DHT-class).
  • Less common (1-10%):
    • Mood changes (typically mild — irritability, mild aggression).
    • Hematocrit elevation (red blood cell mass increase) → cardiovascular risk if untreated.
    • Sleep disruption.
  • Rare-serious (<1% but worth knowing):
    • Oral acetate only: hepatic strain (elevated ALT/AST, cholestasis), peliosis hepatis (rare, dose-and-duration dependent).
    • Cardiac remodeling with chronic high-dose use (concentric LV hypertrophy — documented across AAS class, not Primo-specific).
    • Persistent post-cycle hypogonadism — documented in young AAS users with otherwise healthy HPG axes, and risk likely higher when HPG axis is still maturing (late teens / early 20s).
  • Specific watch periods:
    • At age 20: HPG axis is still consolidating final adult set-point. Suppression at this age has higher theoretical risk of permanent change vs same suppression at 30. This is the core SKIP-AT-20 mechanism.
    • Liver markers must be checked at week 4 of any oral cycle (acetate form).
Interactions3 compounds
  • [testosterone-enanthate](testosterone-enanthate.md):Synergistic
    Primo is almost always run with a testosterone base in adult cycles — exogenous test prevents the symptomatic crash from suppression of endogenous T while Pr…
  • Other DHT-derivatives ([oxandrolone](oxandrolone.md), masteron, winstrol):Avoid
    stacking multiple DHT-class compounds compounds androgenic side effects (hair, skin, prostate) and lipid impact without proportional muscle-building gain.
  • Oral 17α-alkylated AAS together:Avoid
    liver burden stacks supralinearly.
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