Anabolic Steroids/Hormones Human clinical data

Primobolan (Oral)

Methenolone Acetate · Primo Oral

5.0 hours

Half-life

25–100 mg

Typical dose

Oral, daily

Frequency

6–8 weeks

Cycle length

Oral methenolone acetate; mild, low-side, short half-life. Simple model — peak calibrated.

Key takeaways

Oral DHT derivative (methenolone acetate); mild, non-aromatizing, 1-methyl rather than 17-aa.
~5-hour half-life; daily dosing, often split.
Plotter bioavailability (88%) is extrapolated from injectable data — real oral availability is poor.
Gentle on the liver for an oral; still suppressive and frequently counterfeited.

🚧 Expanded guide coming soon. This compound has PK data and a source — a full overview, mechanism, and dosing guide is pending editorial review.

Reported dosing protocols

Protocols reported in research literature and clinic/community use — informational context, not a dosing recommendation.

Use case	Dose	Route	Frequency	Duration
Wasting / underweight (historical label)	50–100 mg daily	Oral	Daily (split)	Weeks–months
Cutting (community)	50–100 mg daily	Oral	Split 2× daily	6–8 weeks

Pharmacokinetic summary

Model tier: Simple (t½ + F, Tmax estimated)
Half-life: 5.0 hours
Cmax: 56.7 ng/dL
Bioavailability: 88%
Typical dose: 25–100 mg

Harm reduction

Aromatizes: No
DHT derivative: Yes
Hepatotoxicity: mild
Injection frequency: Oral, daily

Frequently asked questions

Oral vs injectable Primobolan?

Same hormone. The injectable (enanthate) has a ~10.5-day half-life and twice-weekly dosing; the oral acetate clears in ~5 hours and needs daily dosing. Critically, the oral isn't 17-alpha-alkylated, so much of each dose never reaches circulation — expect a weaker effect per milligram.

Is oral Primo liver-safe?

Safer than alkylated orals, not free of risk. The 1-methyl structure avoids the severe hepatotoxicity of 17-alpha-alkylated compounds, so it rates mild here, but any oral AAS can still move liver enzymes and lipids.

Why is oral Primobolan expensive to run?

Poor oral bioavailability. Without 17-alpha-alkylation the liver clears most of each dose, so reported protocols use 50–100 mg daily for effects the injectable matches at a fraction of the milligrams.

References

Llewellyn Anabolics (11th ed.) — Cmax calibrated to ng/dL serum peak. Oral methenolone acetate PK extrapolated from injectable.
Llewellyn, ANABOLICS (methenolone reference) — Reference text behind the PK calibration; human PK literature on oral methenolone is otherwise sparse.

Primobolan (Methenolone): The Mildest Injectable

8 min read

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