Methenolone (Primobolan)
Also known as: Primobolan, Primo, Methenolone, Primobolan Depot, Methenolon
Mild DHT derivative with a long history in medicine, valued for good tolerability — and the substance most frequently counterfeited on the black market because of its price.
Substance family
Derived from dihydrotestosterone. They do not convert to estradiol, so no water retention — but also no estrogen of their own. Finasteride is useless against their hair loss, because they are already past the step it blocks. Hardest on the lipid profile.
Effects on
Which outcomes this substance acts on — descriptive, not a recommendation.
Strain profile
Where this substance is most likely to hit — a rough orientation, individually dependent on dose, duration and predisposition.
Ester variants
Same active substance, same risk profile — only release rate and injection rhythm differ. The ester determines the timing, not the effect.
| Variant | Half-life | Injection interval |
|---|---|---|
| EnanthatePrimobolan Depot, Primo EThe injectable standard form and the one the dosing figures below refer to. | ~10 days | 1–2× / week |
| Acetate (oral)Primobolan oral, Primo AceNot 17-alpha-alkylated and therefore not liver-toxic — but a large part is broken down on first pass, so far more substance is needed for the same effect. | ~2–3 hours | Daily, split into 2 doses |
The ester also determines how long the substance stays active after the last injection — relevant when planning a recovery phase.
Dosing & protocols by goal
Rough orientation ranges as reported in harm-reduction literature — not an individual treatment plan. Doses are individual and open-ended; frequency depends on the ester or half-life.
Medical (anemia, wasting)
MedicalDose
100 mg / 1–2 weeks
Frequency
Every 1–2 weeks
Cycle length
Time-limited, medically supervised
Historically used for aplastic anemia and in premature infants — one of the few AAS with a paediatric history, which shaped its reputation for tolerability.
Definition phase — Intermediate
IntermediateDose
400–600 mg / week
Frequency
1–2× / week
Cycle length
10–14 weeks
Doses sit higher than with other compounds because the effect is comparatively weak. Below 400 mg / week, little of substance usually happens.
Higher doses
AdvancedDose
> 600 mg / week
Frequency
1–2× / week
Cycle length
Varies
At these quantities the cost is considerable — which is precisely why counterfeits concentrate in this dose range.
Side effect & countermeasure
Typical problems and what you can do to reduce harm — at a glance. Does not replace medical monitoring.
Problem
High risk of counterfeit or underdosed product
Countermeasure
Primobolan is among the most expensive compounds and is correspondingly often faked — frequently relabelled as cheaper substances. An unusually low price is a warning sign, not a bargain. If unexplained side effects appear that do not fit the profile, the actual content is usually the reason.
Problem
Unfavourable lipid profile (HDL drops)
Countermeasure
Milder than with drostanolone, but as a DHTDHTA far more potent androgen the body makes from testosterone — responsible for hair loss and prostate effects. derivative still relevant: cardio, omega-3, possibly citrus bergamot. Check the lipid panel before and during the cycle.
Problem
Suppression of natural testosterone production despite its mild reputation
Countermeasure
Being well tolerated does not mean sparing the hormonal axis. A testosterone base and a post-cycle plan are just as necessary here as with stronger compounds.
Problem
Estradiol falls too low (joint pain, low libido)
Countermeasure
Methenolone does not aromatizearomatizeThe body converting testosterone into estrogen via the aromatase enzyme.. Without a sufficient testosterone base there is no functioning estradiolestradiolThe main estrogen — needed in men too, and damaging in both directions when out of range. level; do not combine with an aromatase inhibitoraromatase inhibitorA drug that blocks the conversion of testosterone to estradiol. unless measurements justify it.
Problem
Accelerated hair loss with a genetic predisposition
Countermeasure
As a DHTDHTA far more potent androgen the body makes from testosterone — responsible for hair loss and prostate effects. derivative it acts on the hair follicle, though less strongly than drostanolone. Finasteride is ineffective here as well. What does apply here is minoxidil, which works independently of DHT, or a topical receptor blocker such as RU58841 or topical spironolactone; ketoconazole treats the scalp inflammation androgens add on top.
Problem
Overestimation of the effect at high cost
Countermeasure
Weigh the expected benefit against the price honestly. The comparatively weak effect means high doses over long periods, which raises both cost and cumulative burden.
Overview
Methenolone enanthate, known everywhere as Primobolan, is one of the few anabolic steroids with a genuine and long medical history. It was used for aplastic anemia, in wasting conditions and even in premature infants — an application that says a great deal about its tolerability profile and shaped the reputation it still carries in the bodybuilding scene today.
That reputation is largely justified: the liver remains unaffected, blood pressure and water retention are barely issues. But two aspects are consistently underestimated. Primobolan suppresses the hormonal axis just as reliably as much harsher substances, and it is the compound most frequently counterfeited on the black market.
Mechanism of Action
Methenolone is a DHT derivative with an additional methyl group at position 1, which protects it from breakdown without requiring 17-alpha-alkylation — the modification that makes oral steroids liver-toxic. This is exactly why the injectable form is well tolerated: it delivers the stability without the hepatic cost.
The compound does not aromatize, so no estradiol arises from it. Its binding to the androgen receptor is comparatively weak, which explains both the mild side-effect profile and the modest effect. The higher doses commonly used are a direct consequence of that weak binding.
The orally available acetate form exists but is inefficient: a large part is broken down on first pass through the liver, so significantly more substance is needed for the same effect.
Typical Context
Primobolan is used in definition phases and by people who prioritise tolerability, often over ten to fourteen weeks alongside a testosterone base. Doses sit noticeably higher than with other compounds because the effect per milligram is lower.
This is where the practical problem arises. Four hundred to six hundred milligrams per week over three months is a considerable amount of an expensive substance — and that price pressure is precisely what makes Primobolan the most attractive target for counterfeiting. Analyses of black-market samples repeatedly find other, cheaper steroids in vials labelled as Primobolan, or substantially less content than declared. Anyone experiencing side effects that do not fit the mild profile should consider the actual contents as the most likely explanation.
Side Effects & Risks
- High probability of counterfeit or underdosed product on the black market
- Suppression of natural testosterone production, comparable to stronger compounds
- Shift in the lipid profile (HDL drops), moderate but present
- Estradiol too low without a sufficient testosterone base
- Accelerated hair loss with a genetic predisposition
- Moderate rise in hematocrit
- Acne, oily skin — less pronounced than with other DHT derivatives
Blood Work & Monitoring
- Lipid profile (LDL, HDL, triglycerides) — baseline and during the cycle
- Total/free testosterone — to check the base and the degree of suppression
- Estradiol (sensitive) — watch for levels that are too low
- Hematocrit & hemoglobin
- Blood pressure — usually unremarkable, still worth tracking
- Liver values (ALT, AST, GGT) — as a baseline; the injectable form is not liver-toxic
Harm-Reduction Notes
- Take the counterfeit risk seriously: a low price for Primobolan almost always means it is not Primobolan
- Side effects that do not match the mild profile point to a different substance in the vial
- Being well tolerated does not mean the axis is spared — a post-cycle plan is just as necessary here
- Without a testosterone base there is no functioning estradiol level; do not add an aromatase inhibitor blindly
- Weigh cost against expected benefit honestly; the weak effect requires long, expensive cycles
- Sterile single-use needles, rotate injection sites
Legal status by region
Regulation differs considerably between jurisdictions and changes over time. This is a rough orientation, not legal advice — check the rules that apply where you are.
| Region | Regulatory status |
|---|---|
| United States | Schedule III controlled substancePrescription required; possession without one is a federal offence. |
| EU / UK | Prescription-only medicineApproved for defined medical indications; supply without prescription is an offence. |
| Canada / Australia | Controlled substance, prescription-onlyImport for personal use is restricted. |
| Parts of Asia & Latin America | Pharmacy availability variesSome countries treat it as pharmacy-dispensed rather than strictly prescription-bound. Enforcement is inconsistent and rules change. |
| Competitive sport | Prohibited at all timesListed by WADA; national anti-doping law applies in addition. |