Metenolone
Methenolone, Methenolone enanthate, Methenolone acetate, Metenolone enanthate, Metenolone acetate, Primobolan, Primobolan Depot, Primo
Forms: Enanthate depot injection (Primobolan Depot) and acetate tablets (Primobolan): one compound, two forms.
Injectable steroidsControlled substanceWADA S1.1 · prohibitedEvidence: approved medicine
A DHT-derived steroid that does not convert to estrogen and is not 17α-alkylated. Sold as the enanthate injection (Primobolan Depot) and the acetate tablet (Primobolan).
Legal status: Controlled anabolic steroid (US Schedule III, UK Class C); the tablets remain a prescription medicine in Japan; status varies by country.
What it gives
What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.
Purpose
Used for slow, lean gains and to keep muscle while dieting; often seen as 'mild'. The tablets are still prescribed in Japan for osteoporosis, wasting and aplastic anemia; the depot injection is largely discontinued.
What people seek and what studies show
In a small randomized trial in stroke rehabilitation, the injectable form enlarged thigh-muscle cross-section by 13–15%, against 3–5% with rehabilitation alone. Its Japanese label describes more protein synthesis with less breakdown, calcium and phosphorus retention, and higher hemoglobin and red cells. Sport doses have not been studied; its reputation for 'quality gains without water' comes from users.
Effects
Evidence: Approved medicine — studied in people for its medical use
Sought effects by goal (as reported)
Mass
Sought for: muscle growth, strength
Cutting
Sought for: keeping muscle in a deficit, hard, dry look
Recomposition
Sought for: muscle growth, keeping muscle in a deficit
Strength
Sought for: strength, muscle growth
Possible side effects
Possible does not mean certain: whether they appear depends on dose, duration, individual response and monitoring. Below — what to watch for and how to notice it early.
14 possible side effects
level · how often it is reportedElevated
Suppression of natural testosterone & fertility
commonSuppresses natural testosterone and sperm production; its label notes reduced sperm with large continuous doses.
How to notice: Lower libido and energy, smaller testicles; low natural testosterone on tests after stopping.
In women: Menstrual changes or missed periods, lower libido and energy; reduced fertility.
Elevated
Black-market quality risk (fakes, contamination)
commonWith the depot largely discontinued, much of what is sold as 'Primobolan' is underground or counterfeit; content and sterility are uncertain.
How to notice: Unexpected effects, pain or infection, a stronger or weaker effect than expected.
Moderate
Worse cholesterol (HDL↓ LDL↑)
commonAs a non-aromatizing androgen it tends to lower HDL; the change is silent and needs a lipid panel.
How to notice: No symptoms — only visible on a lipid panel.
Moderate
Thick blood (hematocrit) / clot risk
possibleIts label reports rises in hemoglobin and red cells; in stacks it adds to hematocrit increases.
How to notice: Often silent; sometimes headaches, flushed face, itch after a hot shower.
Moderate
Androgenic hair loss
possibleA DHT derivative: it can speed up genetic hair loss.
How to notice: More hair in the shower, thinning at the temples or crown.
Moderate
Heart strain / heart-muscle thickening
possibleNo specific data; it adds to the class link between years of AAS use and heart-muscle changes.
How to notice: Shortness of breath on effort, lower endurance, palpitations.
Moderate
Liver strain
rareNot 17α-alkylated, yet its Japanese label warns of liver dysfunction and jaundice and asks for regular liver tests; usually mild and reversible, but a fatal case in a frail patient was described.
How to notice: Usually silent early; later tiredness, nausea, itch, dark urine.
Moderate
Kidney strain
rareNo compound-specific data; long-term heavy AAS use has been linked to protein in urine and kidney scarring (FSGS) in bodybuilders. Cystatin C and a urine test help reveal it.
How to notice: Usually silent; foamy urine or swelling in later stages.
MenLow
WomenHigh
Virilization in women (often irreversible)
possibleIn women its label lists hoarseness that may become irreversible, hair growth, acne, menstrual changes and clitoral enlargement; menstrual changes often come first.
How to notice: Hoarse or deeper voice, new facial or body hair, menstrual changes, clitoral enlargement.
Low
Too-low estrogen (joints, libido, mood, lipids)
possibleDoes not aromatize; when used on its own, low estrogen may show as joint aches, low libido or low mood.
How to notice: Aching, stiff joints, low libido, flat mood, poor sleep.
Low
Acne, oily skin
possibleAcne is listed on its label for both men and women.
How to notice: Oily skin, spots on back, shoulders and face.
Low
Prostate growth / PSA rise
possibleIts label asks for regular prostate checks in men.
How to notice: More frequent urination or a weak stream, especially at night.
Low
Higher blood pressure
possibleSodium and fluid retention can occur, mainly a concern with heart or kidney disease.
How to notice: Often silent; sometimes headaches, flushing, nosebleeds — a home monitor shows it.
Low
Injection pain, infection, oil cough
possibleSoreness after the depot injection is possible; redness, heat or fever suggest infection.
How to notice: Soreness, lumps; a short coughing fit right after an injection.
What the levels mean
Lowbackground — just be aware
Moderatewatch for signs
Elevatedneeds regular control
Highcritical — can be life-threatening or permanent
Level: general category from the literature, not your personal risk
How often
- common
- reported often
- possible
- reported in some people
- rare
- reported occasionally
How to lower the risks
For 12 of 14 possible side effects there are specific ways to lower the chance: everyday measures, supplements and options a doctor may consider. For the rest — general advice. No measure removes a risk completely. Prescription medicines are listed only for a doctor to decide on, after tests — they have side effects of their own.
ElevatedSuppression of natural testosterone & fertility
Check hormones before and after; if they stay low, see an endocrinologist.
Measure
Only if a doctor prescribes
How each option helps (7)
- Regular blood tests — LH, FSH and testosterone show how deep suppression is and whether natural production has recovered afterwards.
- Working with a doctor — Assesses how deep suppression is and guides recovery afterwards, including fertility testing.
- Clomiphene — A doctor may consider it after stopping, guided by hormone tests; recovery after long use can still take months. Risks: vision changes, mood swings, rare clots. Has side effects of its own.
- Human chorionic gonadotropin (hCG) — A doctor may consider it to preserve fertility (in men it keeps the testes working); it does not restart the pituitary, so natural LH still has to recover. Risks: higher estradiol, gynecomastia. Has side effects of its own.
- Tamoxifen — A doctor may consider it after steroids are stopped, guided by hormone tests; it has not been tested for this after steroid use. Risks: blood clots, vision changes. Has side effects of its own. Not offered to women: in the women’s view it adds to a risk this substance already carries.
- Follicle-stimulating hormone (follitropins, menotropins) — A fertility doctor may consider adding it to hCG when semen tests and FSH stay low; it does not restart the pituitary. Risks: gynecomastia, acne. Has side effects of its own.
- Toremifene — A doctor may consider it after steroids are stopped, guided by hormone tests; it raised testosterone in subfertile men but was never tested after steroids. Risks: QT prolongation, clots. Has side effects of its own. Not offered to women: in the women’s view it adds to a risk this substance already carries.
ElevatedBlack-market quality risk (fakes, contamination)
Products obtained without a prescription are often fake, mislabeled or non-sterile, and there is no way to check at home. For legal supplements, look for third-party testing (Informed Sport, NSF).
ModerateWorse cholesterol (HDL↓ LDL↑)
Avoid combining several oral steroids; regular cardio, soluble fiber (psyllium), less saturated fat and alcohol; if LDL/ApoB stay high, a doctor may consider a statin. Omega-3 only lowers triglycerides.
Measure
Supplement or OTC product
How each option helps (8)
- Regular blood tests — A lipid panel with ApoB shows how far HDL has dropped and LDL risen — changes you cannot feel.
- Working with a doctor — Interprets lipids and ApoB and decides whether a statin or other therapy is warranted.
- Avoiding alcohol and other liver stressors — Alcohol raises triglycerides; its small HDL bump does not lower heart risk.
- Regular cardio training — Raises HDL a little and lowers triglycerides; it cannot offset a steroid-driven fall in HDL on its own.
- Berberine — Placebo-controlled meta-analysis: LDL about 0.5 and triglycerides about 0.4 mmol/L lower; HDL unchanged. Trials are mostly small; no statin substitute.
- Citrus bergamot — Pooled small trials show lower LDL and triglycerides, but certainty is low to very low; it is no replacement for statins.
- Omega-3 (fish oil, EPA/DHA) — Clearly lowers triglycerides but does not fix the steroid HDL drop, the main lipid harm; DHA-containing oils may even raise LDL slightly.
- Psyllium husk fiber — Lowers LDL by about 0.2–0.3 mmol/L (roughly 5–10%), also on top of doctor-prescribed statins; no effect on HDL.
ModerateThick blood (hematocrit) / clot risk
Check the blood count regularly; if hematocrit stays high, a doctor decides — usually stopping or reducing the cause, sometimes therapeutic phlebotomy, never blood-bank donation. Avoid dehydration: it thickens the blood further.
Measure
How each option helps (3)
- Regular blood tests — A blood count shows hematocrit and hemoglobin climbing toward the range where clot and stroke risk rises.
- Therapeutic phlebotomy prescribed by a doctor — Only on a doctor's decision, never at a blood bank. Lowers hematocrit quickly but temporarily; repeated sessions drain iron, and a lower clot risk is unproven.
- Working with a doctor — Manages thick blood by changing what you use or, if justified, by therapeutic phlebotomy.
ModerateAndrogenic hair loss
Ketoconazole shampoo, minoxidil, a dermatologist early if you are prone to it.
Supplement or OTC product
How each option helps (1)
- Minoxidil (topical) — Slows thinning and regrows some hair; scalp itching and early temporary shedding are common, unwanted facial hair possible. Gains fade once stopped.
ModerateHeart strain / heart-muscle thickening
Regular cardio, blood pressure control, an echo as a baseline and then yearly.
Measure
How each option helps (4)
- Heart screening: ECG and echocardiogram — Echocardiography shows wall thickening and reduced pumping early, while stopping AAS and treating BP can still help.
- Working with a doctor — Orders ECG and echocardiography and treats early heart changes.
- Home blood-pressure monitoring — Keeping BP controlled is one of the main ways to limit heart-wall thickening.
- Regular cardio training — Supports heart and vessel function, but does not reverse steroid-related heart thickening or weakening.
ModerateLiver strain
No alcohol, no other liver stressors, limit oral steroids and their combinations, check liver enzymes.
Measure
Supplement or OTC product
How each option helps (5)
- Avoiding alcohol and other liver stressors — Removes a major extra liver stressor during oral steroids and other hepatotoxic drugs.
- Regular blood tests — ALT, AST, GGT and bilirubin show liver strain before symptoms; heavy lifting alone raises AST/ALT for days, and GGT helps tell muscle from liver.
- Ademetionine (SAMe) — Used for intrahepatic cholestasis in some countries, but trials are small and of low quality; untested in steroid users. Stopping the oral steroid matters most.
- N-acetylcysteine (NAC) — Restores glutathione; proven in paracetamol poisoning and helped in early acute liver failure of other causes, but untested in steroid users.
- TUDCA (tauroursodeoxycholic acid) — Improves bile flow in cholestatic disease; in steroid cholestasis only case reports, with failures in severe cases. Stopping the oral steroid matters most.
ModerateKidney strain
Drink enough water, control blood pressure, avoid regular painkillers (NSAIDs).
Measure
How each option helps (3)
- Fluid & electrolyte management — Good hydration eases kidney stress from heavy training and heat; dehydration plus NSAIDs is a classic cause of acute kidney injury.
- Regular blood tests — Creatinine reads high in muscular people and with creatine; cystatin C and a urine test give a truer picture of the kidneys.
- Working with a doctor — Investigates protein in the urine or falling kidney function and can start treatment that slows kidney damage.
MenLow
WomenHigh
Stop at the first voice change and see a doctor — early stopping matters.
Measure
How each option helps (1)
- Working with a doctor — Steroid labels say to stop at the first mild signs (hoarse voice, facial hair, clitoral growth) to prevent permanent change; checks catch them early but do not make use safe.
Low-level side effects
Low estrogen
Avoid controlling estrogen blindly; adjust only by blood tests with a doctor.
Measure
How each option helps (1)
- Regular blood tests — Testing ends guesswork use of aromatase inhibitors — prescription drugs that can push estrogen too low and harm joints, libido, mood and lipids.
Acne
Gentle skin care, cleansing after training, a dermatologist if it spreads.
Supplement or OTC product
How each option helps (3)
- Adapalene — Reduces spots in many users. Redness, scaling, dryness and stinging are common early and usually ease; acne may look worse at first. Rarely, allergic swelling.
- Benzoyl peroxide — A first-line acne option. Dryness, redness and peeling are common at first; it bleaches hair and fabric; rarely, serious allergic reactions. Severe steroid acne needs a dermatologist.
- Zinc — Trials show a modest drop in inflamed spots, weaker than antibiotics; steroid acne is driven by androgens.
Prostate
PSA as a baseline, especially after 40; a urologist if urination changes.
Measure
How each option helps (1)
- Regular blood tests — PSA tracks prostate changes on androgens — most relevant after 40 or with urinary symptoms.
Blood pressure
Less salt, regular cardio, good sleep; home readings; a doctor if it stays high.
Measure
Supplement or OTC product
How each option helps (8)
- Home blood-pressure monitoring — Seated, rested readings on several days show your true BP; persistently high values are a signal to see a doctor.
- Regular cardio training — Regular aerobic training lowers resting BP by a few mmHg, more in people with high BP.
- Working with a doctor — Diagnoses persistent hypertension and prescribes treatment when needed.
- Avoiding alcohol and other liver stressors — Regular drinking raises blood pressure; cutting it out lowers it.
- Coenzyme Q10 — Inconsistent: some analyses show a small systolic drop in cardiometabolic disease, but a Cochrane review found no clinically meaningful effect.
- Magnesium — Meta-analysis of trials: about 2 mmHg lower systolic pressure on average.
- Omega-3 (fish oil, EPA/DHA) — Small drop of a few mmHg, mainly in people with untreated high blood pressure.
- Taurine — Meta-analysis of 20 small trials: about 4 mmHg lower systolic pressure on average.
Injection site
Sterile technique, never share needles, vials or pens; see a doctor for a hot, swollen site. If equipment was ever shared, test for HIV and hepatitis B/C and ask about hepatitis B vaccination.
Check-ups and blood tests
Which tests and check-ups to do and when. This is a guide — agree the exact schedule with your doctor.
Baseline tests
your own starting values — every later result is compared with them
Lipid panel (HDL, LDL, triglycerides, ApoB)low estrogen, cholesterol
Liver panel (ALT, AST, GGT, bilirubin)liver
Complete blood count (hematocrit, hemoglobin)hematocrit
Kidney panel (creatinine, eGFR, cystatin C)kidneys
Testosterone (total, free), LH, FSH, SHBGnatural testosterone
Estradiol (sensitive assay)low estrogen
PSA
Home blood-pressure logheart, kidneys
ECGheart
Echocardiogram (heart ultrasound)heart
Urinalysiskidneys
While taking
about 4–6 weeks in, then every 6–8 weeks — agree the exact schedule with your doctor
Lipid panel (HDL, LDL, triglycerides, ApoB)low estrogen, cholesterol
Liver panel (ALT, AST, GGT, bilirubin)liver
Complete blood count (hematocrit, hemoglobin)hematocrit
Kidney panel (creatinine, eGFR, cystatin C)kidneys
Estradiol (sensitive assay)low estrogen
Home blood-pressure logheart, kidneys
Urinalysiskidneys
After stopping
4–8 weeks after stopping (later after long-acting injections), then until values return to baseline
Lipid panel (HDL, LDL, triglycerides, ApoB)low estrogen, cholesterol
Liver panel (ALT, AST, GGT, bilirubin)liver
Complete blood count (hematocrit, hemoglobin)hematocrit
Kidney panel (creatinine, eGFR, cystatin C)kidneys
Testosterone (total, free), LH, FSH, SHBGnatural testosterone
Semen analysisnot earlier than 3 months after stopping, then every 3 months until normalnatural testosterone
Every year
with regular or repeated use
ECGheart
Echocardiogram (heart ultrasound)heart
Which doctors can help
Sports physiciancoordinates everything
Cardiologistcholesterol, hematocrit, heart
Endocrinologistnatural testosterone, low estrogen
Gastroenterologist / hepatologistliver
Nephrologistkidneys
Dermatologisthair loss
Gynecologistvirilization, natural testosterone (women)
At home
- Home blood pressure: 2–3 times a week in the morning, keep a log
Get medical help at once if
- Swelling, pain or redness in one leg; sudden shortness of breath or chest pain; sudden one-sided weakness or numbness, trouble speaking or seeing — seek urgent care.
- Chest pain or pressure, breathlessness on light effort, swollen ankles, fainting — seek urgent care.
- Yellow skin or eyes, dark urine, pale stools, intense itching, pain under the right ribs — see a doctor now; sudden severe abdominal pain with dizziness or fainting — call emergency services.
- Much less urine than usual, cola-colored urine, new swelling, flank pain — see a doctor now.
- Deepening voice, new facial hair, clitoral enlargement — stop and see a doctor: changes can become permanent. (women)
In an emergency, call your local emergency number.
For women
Popular among women as 'mild', but its label warns that hoarseness may become irreversible and lists hair growth and clitoral enlargement. Menstrual changes often come first — an early sign of androgen excess.
Myth & fact
Myth
“Primobolan doesn't touch the liver.”
Fact
It is not 17α-alkylated and is gentler than most oral steroids, yet its Japanese label warns of liver dysfunction and jaundice and asks for periodic liver tests.
Combinations
Overlap5α-reductase inhibitor with steroids it cannot affect
DHT-derived steroids, trenbolone and trestolone act without 5α-reductase, so finasteride and dutasteride do not lower their effect on hair or prostate; they only reduce DHT made from testosterone, while finasteride and dutasteride keep their own side effects.
Drostanolone1-TestosteroneOxandroloneStanozololOxymetholoneMesteroloneMethasteroneTrenboloneTrestoloneMethyl-1-testosterone (M1T)Desoxymethyltestosterone (DMT, Madol, Pheraplex)Epistane (methylepitiostanol, Havoc)ProstanozolMestanoloneStenbolone1-Andro (1-androsterone) and related prohormonesEpiandrosterone (Epi-Andro)Androstanolone (dihydrotestosterone, DHT)Sources
Primobolan tablets (metenolone acetate) — Japanese prescribing information, Bayer, rev. Aug 2020 (KEGG MEDICUS) (opens in a new tab)Okamoto S et al. Change in thigh muscle cross-sectional area through administration of an anabolic steroid during routine stroke rehabilitation in hemiplegic patients. Am J Phys Med Rehabil 2011 (opens in a new tab)Tsukamoto N et al. Fatal outcome of a patient with severe aplastic anemia after treatment with metenolone acetate. Ann Hematol 1993 (opens in a new tab)
Check how Metenolone combines with your stack
Possible side effects by body system, combinations, how to lower the risks and which tests to do — free.
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