Methenolone (Primo / Primobolan)
FROM THE REEL TO THE RESEARCH
The quick answer, with the evidence attached.
Both belong to the anabolic-androgenic steroid family, but their reputations are much more alike than their evidence bases. Methenolone has small human rehabilitation studies relevant to muscle. The drostanolone human studies reviewed here concern other endpoints. Neither provides a reliable healthy-lifter head-to-head comparison of muscle growth.
From Primo vs Masteron · Editorial update 2026-10-16
Related comparisons (1)
- Primo vs Masteron — Similar roots. Different evidence.
What it is & what research shows
Reference overviewMethenolone (metenolone) is a synthetic anabolic-androgenic steroid. Primobolan names are used for methenolone ester and acetate formulations, and the ester or route changes the pharmacokinetic question. A small randomized study in stroke rehabilitation measured greater thigh muscle-area increases with metenolone than control over six weeks. A separate nonrandomized rehabilitation study examined strength. These populations do not establish results in healthy lifters or a benefit from adding Primo to TRT. [1.1][1.2][1.3][1.4]
The cited sources do not establish a human half-life for every formulation, a safe athletic dose or how much muscle an athlete could expect to gain. Anabolic-steroid risks can include adverse lipid, liver, blood, cardiovascular and reproductive effects; Results depend on the formulation studied. See the rehabilitation studies linked above and the separate historical study below. [2.1]
Sources & reading scope
- [1.1] PubMed methenolone literature searchScientific database search · formulation-specific literature varies
- [1.2] WADA Prohibited ListAnti-doping reference · anabolic agents
- [1.3] Okamoto et al., thigh muscle area during stroke rehabilitation (2011)Randomized human study · indexed abstract assessed
- [1.4] Shimodozono et al., strength training after stroke (2010)Nonrandomized human study · abstract assessed
- [2.1] WADA Prohibited ListAnti-doping reference · anabolic agents
Study-summary coverage
No completed study summaries are linked to this compound page yet. This is a coverage gap on PED Evidence, not evidence that human studies or other research do not exist.
Filter, save and compare Methenolone studies →More about Methenolone: identity, safety & reference details
Also known as Metenolone · methenolone enanthate · methenolone acetate · metenolone enanthate · Primobolan · Primobolan Depot · Methenolone enanthate · Methenolone acetate injection · Methenolone acetate
Start with the research
An outcome-specific synthesis has not been prepared for this compound. This is a coverage gap, not evidence that it has no effect.
Open studies and trial records- Uses & research
A small randomized study in stroke rehabilitation measured greater thigh muscle-area increases with metenolone than control over six weeks. A separate nonrandomized rehabilitation study examined strength. These populations do not establish results in healthy lifters or a benefit from adding Primo to TRT. [3][4]
- Known half-life
No source-verified value in this profile yet. A treatment schedule or duration of an effect is not a drug half-life.
Half-life describes how quickly the measured drug concentration falls by half. It does not set a dosing interval.- Evidence & important limits
The cited sources do not establish a human half-life for every formulation, a safe athletic dose or how much muscle an athlete could expect to gain. Anabolic-steroid risks can include adverse lipid, liver, blood, cardiovascular and reproductive effects; Results depend on the formulation studied. [2]
Safety & evidence boundaries
The cited sources do not establish a human half-life for every formulation, a safe athletic dose or how much muscle an athlete could expect to gain. Anabolic-steroid risks can include adverse lipid, liver, blood, cardiovascular and reproductive effects; Results depend on the formulation studied.
Explore safety questions by system
These are literature filters, not claims that this compound causes each effect. A keyword match is not a confirmed adverse reaction.
Identity, names & formulations
Canonical compound: Methenolone · methenolone
Searchable names: Metenolone, methenolone enanthate, methenolone acetate, metenolone enanthate, Primobolan, Primobolan Depot, Methenolone enanthate, Methenolone acetate injection, Methenolone acetate
Names share a parent research page. Different esters, salts, routes and brands are not assumed to have the same half-life, indication or exposure.
- Methenolone enanthateInjectable · Primobolan DepotFind this formulation in the archive
- Methenolone acetate injectionInjectable · Named formulation
Oral acetate and injectable enanthate findings do not validate injectable acetate.
Find this formulation in the archive - Methenolone acetateOral · PrimobolanFind this formulation in the archive
Research subject only. Excluded from evidence-leader and supportive-compound recommendations.
Combination evidence stays attached to the studied combination. It is not automatically assigned to each ingredient.
Understand the evidence types
Read the model and design first, then the population, outcome and limitations. These categories describe evidence, not a best-compound ranking.
- Randomized human trials
- Compare assigned interventions. Randomization does not by itself establish low bias or relevance to every population.
- Controlled human studies
- Use a comparison group; allocation and confounding still matter.
- Prospective human research
- Follows participants forward. It may be observational or interventional, so this is not a separate quality grade.
- Observational human research
- Describes associations. Confounding can explain differences.
- Case reports and series
- Useful for unusual events and safety signals, not reliable rates or effect sizes.
- Animal research
- Can test biology and function in a living model. Human exposure, benefit and safety remain separate questions.
- Cell and tissue research
- Tests responses in a preparation, including human-derived cells. It is not a human participant trial.
- Mechanistic and computational evidence
- Helps explain or predict a pathway; predictions need experimental and clinical testing.
- Anecdotal reports
- Self-reported experiences can generate questions. Product identity, selection bias and other interventions may be uncontrolled.
Systematic reviews synthesize studies and depend on their quality. Preprint status and abstract versus full-paper reading are separate labels. Citation popularity measures attention, not reliability. A study summary is not a formal quality appraisal.
Sources for this profile
- 1. PubMed methenolone literature search Scientific database search · formulation-specific literature varies
- 2. WADA Prohibited List Anti-doping reference · anabolic agents
- 3. Okamoto et al., thigh muscle area during stroke rehabilitation (2011) Randomized human study · indexed abstract assessed
- 4. Shimodozono et al., strength training after stroke (2010) Nonrandomized human study · abstract assessed
Reference facts checked 2026-10-17. Source scope is listed above; this is not a formal quality appraisal. See each label for full prescribing information.
Study model describes the source. Confidence depends on methods, replication, population and outcome.
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