Trust Signals
- Written by the FormBlends Medical Team, reviewed against primary case reports and pharmacology literature
- No affiliate links to either compound. Both are Schedule III controlled substances; this page does not facilitate purchase
- Every major claim is graded in the evidence ledger below
- Speculative claims are labeled as such throughout
- Last reviewed and updated: 2026-05-29
Key Takeaways
- Superdrol (methasterone) is a 17-alpha-alkylated oral steroid; that C-17 modification is the direct chemical reason it is hepatotoxic while trenbolone is not
- Trenbolone has never received FDA approval for human use; all human data comes from case reports and observational studies, not controlled trials
- Both compounds suppress endogenous testosterone via HPG axis suppression; recovery can take months and is not guaranteed
- Neither compound aromatizes to estrogen, which removes estrogenic gynecomastia risk but eliminates cardioprotective and joint-supportive estrogen effects, worsening lipid profiles
- Published case reports document acute liver injury, including cholestatic hepatitis and peliosis hepatis, specifically attributed to methasterone use
Direct Answer: Superdrol vs Tren at a Glance
Superdrol and tren are both high-potency anabolic androgens but with completely different toxicity profiles. Superdrol carries acute hepatotoxicity risk because of its oral 17-alkylation. Tren carries greater cardiovascular, neuropsychiatric, and androgenic risk. No human RCT compares them. Both are Schedule III controlled substances. Neither is a safe choice outside tightly monitored clinical use.
Check your GLP-1 eligibility
Use our free BMI Calculator to see if you may qualify for provider-reviewed GLP-1 therapy.
Try the BMI Calculator →Table of Contents
- What are Superdrol and Tren chemically?
- How do they work? Mechanism with numbers
- Evidence ledger: what is actually proven?
- What side effects do each cause?
- What most pages get wrong about Superdrol vs Tren
- Why the rules of thumb exist: the chemistry
- Honest head-to-head comparison table
- Label literacy and sourcing red flags
- Legal status and regulatory history
- Safer alternatives with actual RCT support
- FAQ
- Sources
- Disclaimers
What Are Superdrol and Tren Chemically?
Superdrol is the trade name for methasterone (2alpha-methyl-5alpha-dihydrotestosterone-17beta-ol, or 2alpha,17alpha-dimethyl-5alpha-androstan-17beta-ol-3-one). It was originally synthesized in the 1950s by Syntex but was never approved as a pharmaceutical. It reappeared as an over-the-counter "designer steroid" supplement around 2005 before the DEA scheduled it.
Trenbolone is a 19-nor (19-nortestosterone) derivative. The most commonly encountered forms are trenbolone acetate (short ester, used in veterinary products such as Finaplix) and trenbolone enanthate (longer ester, no approved veterinary or human product). It was developed for veterinary cattle use to promote lean muscle growth before slaughter and has never been approved for human use by any major regulatory agency.
How Do They Work? Mechanism with Numbers
Methasterone binds androgen receptors (AR) with high affinity. Standard preclinical screening uses the rat levator ani and ventral prostate assay to estimate anabolic-to-androgenic ratios relative to a reference androgen such as methyltestosterone. Published pharmacology literature characterizes methasterone as having a markedly high anabolic-to-androgenic ratio in this model, meaning pronounced anabolic activity relative to androgenic activity compared with the reference compound. The specific numerical values reported vary by source and assay conditions, and no single attribution to a named study can be confirmed with confidence; the figures that circulate widely in bodybuilding literature should be treated as approximations from screening assays rather than precise clinical data. Critical caveat: rat bioassay ratios do not reliably predict human tissue selectivity. The androgen receptor is the same protein in both species, but tissue distribution, 5-alpha reductase activity, and metabolic context differ substantially.
Trenbolone binds the androgen receptor with substantially greater affinity than testosterone in competitive binding assays, a finding reported consistently across in vitro receptor studies in the pharmacology literature (exact figures vary by assay conditions and source). Trenbolone is also a potent progestin, binding the progesterone receptor with meaningful affinity, which is the mechanism behind its progestogenic side effects including potential gynecomastia despite no aromatization. Additionally, trenbolone binds glucocorticoid receptors, which is proposed as a mechanism for its anti-catabolic effects, though the clinical significance of this in humans at typical illicit doses is not established by controlled data.
Both compounds suppress luteinizing hormone (LH) and follicle-stimulating hormone (FSH) via negative feedback on the hypothalamic-pituitary-gonadal (HPG) axis, suppressing endogenous testosterone production. Trenbolone's suppression is considered particularly severe in observational reports, with some users reporting persistent hypogonadism lasting months to years after cessation.
Evidence Ledger: What Is Actually Proven?
| Claim | Best Evidence Type | Effect Direction | Confidence |
|---|---|---|---|
| Methasterone causes cholestatic liver injury | Case reports (multiple published) | Harmful | Moderate (no RCT, but biologically plausible mechanism, consistent case series) |
| Trenbolone suppresses endogenous testosterone | Animal studies, case reports, pharmacology | Harmful | Moderate to High |
| Both compounds worsen HDL cholesterol | Observational, case reports, class-effect pharmacology | Harmful | Moderate |
| Trenbolone causes left ventricular hypertrophy | Animal studies (rodent), observational human reports | Harmful | Low to Moderate (no human RCT) |
| Trenbolone has neurotoxic effects | Rodent studies (oxidative stress markers in brain tissue) | Harmful (preclinical) | Very Low for humans (mechanism only, no human trial) |
| Methasterone increases lean mass and strength | Anecdotal, case reports (no human RCT) | Positive (anabolic) | Very Low |
| Trenbolone increases lean mass in cattle | Veterinary RCT (bovine) | Positive in cattle | Moderate for bovine; does not translate directly to human dosing or safety |
| Both compounds cause HPG axis suppression | Pharmacology, class effect, case reports | Harmful | High (mechanism is established) |
| Neither compound aromatizes | In vitro enzyme assays, structural chemistry | Neutral/mixed | High |
| PCT with SERMs fully restores hormonal function | No controlled trials | Uncertain | Very Low |
What Side Effects Does Each Cause?
Superdrol (Methasterone):
- Hepatotoxicity: cholestatic jaundice, elevated AST and ALT, peliosis hepatis. Multiple case reports in peer-reviewed literature (Jasiurkowski et al., 2006, American Journal of Gastroenterology; Nasr and Ahmad, Dig Dis Sci, 2009) document acute liver injury attributed to methasterone-containing supplements.
- Severe dyslipidemia: significant HDL reduction consistent with other 17-alpha-alkylated oral androgens
- HPG axis suppression and testicular atrophy
- Androgenic effects: acne, scalp hair thinning in genetically predisposed individuals
- Lethargy and fatigue, reported frequently by users, possibly related to liver stress
Trenbolone:
- Severe HDL suppression and adverse lipid profile changes
- Cardiovascular hypertrophy: rodent studies show myocardial structural changes at anabolic doses; human observational data suggest similar risks
- Androgenic alopecia acceleration in predisposed individuals
- Neuropsychiatric effects: aggression, anxiety, insomnia, night sweats (widely reported in observational literature)
- Progestogenic effects: potential gynecomastia via progesterone receptor activation despite no aromatization
- Tren cough: an acute cough response shortly after injection, thought to result from oil or prostaglandin release into the vasculature
- Persistent hypogonadism post-cessation, documented in case reports
What Most Pages Get Wrong About Superdrol vs Tren
1. The "no aromatization means safer" myth. Both compounds are often marketed or discussed as safer because they do not convert to estrogen. This is backwards for cardiovascular risk. Estrogen plays a meaningful role in maintaining HDL cholesterol and vascular function. Stripping estrogenic activity while adding strong androgenic activity amplifies dyslipidemia. Non-aromatizing androgens consistently produce worse lipid profiles than aromatizing ones at equivalent anabolic doses.
2. Confusing hepatotoxicity mechanisms. Many posts say "tren is not liver toxic because it's injectable." Trenbolone's lower hepatotoxicity relative to Superdrol is not primarily because it is injectable. It is because it lacks the 17-alpha-alkyl group that makes methasterone resistant to hepatic first-pass conjugation. An injectable 17-alkylated steroid would still be hepatotoxic. Conversely, trenbolone is not entirely liver-benign; high-dose use can still elevate liver enzymes in some users, though far less consistently than 17-alkylated orals.
3. Ignoring trenbolone's progestogenic activity. Because tren does not aromatize, many users assume no risk of gynecomastia. Trenbolone binds the progesterone receptor with meaningful affinity. Progesterone receptor activation in breast tissue can promote gynecomastia, particularly when combined with any residual estrogen from co-administered testosterone. Aromatase inhibitors do not block this pathway.
4. Treating rat bioassay ratios as human outcome predictors. The anabolic-to-androgenic ratio figures that circulate widely (often listed as exact numbers) come from the rat levator ani/ventral prostate assay. These are screening tools developed for drug development, not clinical dose-prediction instruments. Human tissue responses reflect different 5-alpha reductase distribution, receptor isoforms, and metabolic context. Precise ratio figures attributed to specific historical studies should be treated with caution; many cannot be traced to a verifiable primary source.
Why the Rules of Thumb Exist: The Chemistry
Why is Superdrol liver toxic but Trenbolone is not (or far less so)?
The 17-alpha-alkylation in methasterone places a methyl group at carbon 17 of the steroid backbone. The liver primarily inactivates steroids via conjugation (glucuronidation and sulfation) at the 17-beta hydroxyl group. The 17-alpha methyl group creates steric hindrance that slows this conjugation, allowing the compound to survive hepatic first pass and reach systemic circulation orally. The cost is prolonged hepatic exposure to an active, lipophilic steroid that disrupts bile acid transport proteins (particularly BSEP, the bile salt export pump), impairs canalicular bile flow, and produces intrahepatic cholestasis. This is the same mechanism behind cholestatic jaundice seen with other 17-alkylated oral steroids such as methyltestosterone and stanozolol.
Trenbolone has no alkylation at C-17. Injectable administration also bypasses hepatic first pass entirely (the ester is cleaved in peripheral tissue), further reducing the hepatic concentration gradient.
Why does trenbolone cause night sweats? This is not fully established mechanistically. The most cited hypothesis involves trenbolone's glucocorticoid receptor partial agonism and its effects on hypothalamic thermoregulation. Some researchers have proposed it relates to elevated metabolic rate from androgenic stimulation. No human study has definitively resolved this. It is a real and commonly reported phenomenon, but the exact mechanism remains speculative.
Honest Head-to-Head Comparison
| Parameter | Superdrol (Methasterone) | Trenbolone | Who "Wins" (with honest caveat) |
|---|---|---|---|
| Route of administration | Oral | Injectable (IM) | Tren for convenience to some; Superdrol for needle-averse (both carry harm) |
| Hepatotoxicity | High risk (17-alpha-alkylation) | Low to moderate risk | Tren: lower acute liver risk |
| Cardiovascular risk | High (dyslipidemia, LVH risk) | High (severe dyslipidemia, LVH, reported in rodents and observations) | Roughly equal, both poor |
| HPG suppression | Significant | Severe, often described as among the worst of common androgens | Superdrol: slightly less suppressive per reports (no RCT) |
| Aromatization | None | None | Neither; both lose estrogen's protective effects |
| Progestogenic activity | Low | High | Superdrol: lower gyno risk via this pathway |
| Neuropsychiatric risk | Moderate (reported fatigue, mood) | High (aggression, insomnia, anxiety widely reported) | Superdrol: probably lower |
| Androgenic (hair, skin) | Moderate | High (does not reduce via 5AR; no DHT conversion) | Superdrol: possibly lower scalp risk; both cause acne |
| Human RCT efficacy data | None | None for humans | Neither: both lose to any intervention with actual trial data |
| Legal status (US) | Schedule III | Schedule III | Both illegal without prescription |
| FDA approval (human) | Never approved | Never approved | Both fail; no approved human use |
| vs. Creatine + resistance training | More risk, better short-term mass (anecdote) | More risk, better short-term mass (anecdote) | Creatine wins on safety with meaningful RCT efficacy data |
Label Literacy and Sourcing Red Flags
Because neither compound is approved for human use, products sold online or in some supplement markets are either veterinary diversion (trenbolone) or grey-market/illicit synthesis (methasterone). Neither category has pharmaceutical quality standards applied. Key red flags:
- No Certificate of Analysis (COA) from an independent third-party lab: Without HPLC-verified potency and purity data, the stated dose is unverified. Underground lab products have been found to contain anywhere from zero active compound to multiples of the stated dose.
- Undeclared compounds: Cross-contamination or deliberate adulteration with other androgens, including ones not on the label, has been documented in analytical testing of underground lab products.
- Ester length matters for trenbolone dosing: Trenbolone acetate has a very short half-life (roughly 1 to 3 days), meaning injection frequency must be high for stable blood levels. Trenbolone enanthate is slower (roughly 5 to 7 days). Misidentified ester leads to incorrect dosing schedules and unpredictable blood level swings.
- Oil quality for injectables: Pharmaceutical injectable vehicles use sterile, pyrogen-tested carrier oils. Underground preparations vary widely. Post-injection infections, abscesses, and sterile abscesses from oil impurities are documented in the medical literature.
- Superdrol sold as "prohormone" or "dietary supplement": After DEA scheduling in 2012, methasterone was removed from legal sale. Products appearing to contain it are illicit. Any supplement label claiming "methasterone" or known synonyms is an illegally marketed controlled substance.
Legal Status and Regulatory History
In the United States, anabolic steroids are classified as Schedule III controlled substances under the Anabolic Steroid Control Act of 1990, expanded by the Anabolic Steroid Control Act of 2004, and further amended by the Designer Steroid Control Act. Trenbolone was explicitly named in scheduling. Methasterone was added to Schedule III by the DEA effective 2012 following its appearance as a designer supplement ingredient.
Trenbolone holds a European Medicines Agency authorized veterinary marketing authorization (as a growth promoter in some territories historically), but its use as a growth promoter in food animals is banned in the European Union. It has never had human pharmaceutical approval anywhere. The World Anti-Doping Agency (WADA) prohibits both compounds in and out of competition under the S1 Anabolic Agents category.
Safer Alternatives with Actual RCT Support
This is the section commodity pages omit because it requires conceding the peptide or compound under review does not win every comparison.
| Intervention | Best Evidence Level | Effect on Lean Mass / Strength | Safety Profile |
|---|---|---|---|
| Progressive resistance training | Multiple large RCTs and meta-analyses | Consistent lean mass and strength gains | Excellent; risks are musculoskeletal with poor form |
| Creatine monohydrate | Multiple RCTs, Cochrane-level evidence | Modest but real strength and power gains (roughly 5 to 15% in trained individuals across trials) | Very good; no serious adverse events in reviewed trial data |
| Adequate dietary protein (1.6 to 2.2 g/kg/day) | Meta-analyses of RCTs (Morton et al., 2018, BJSM) | Maximizes muscle protein synthesis response to training | Excellent in healthy individuals |
| Testosterone (prescribed, monitored) | Multiple RCTs in hypogonadal men | Significant lean mass increase and strength at therapeutic doses | Moderate risk with monitoring; known profile, FDA-approved |
| Superdrol (methasterone) | No human RCT | Likely significant (anecdote, preclinical) | Poor: hepatotoxicity, cardiovascular, illegal |
| Trenbolone | No human RCT; veterinary RCT only | Likely significant (observational) | Poor: cardiovascular, neuropsychiatric, illegal |
FAQ
What is the main difference between Superdrol and Tren?
Superdrol (methasterone) is a 17-alpha-alkylated oral anabolic steroid with significant hepatotoxicity risk. Trenbolone is an injectable veterinary-derived androgen with no liver alkylation but severe neurological, cardiovascular, and androgenic side effects. Both are Schedule III controlled substances in the US and illegal without a prescription.
Is Superdrol or Tren more dangerous?
They carry different danger profiles. Superdrol poses acute hepatotoxicity risk including cholestatic jaundice and peliosis hepatis documented in case reports. Tren carries higher cardiovascular, neuropsychiatric, and androgenic risks. Neither has an established safe dose in humans outside clinical settings.
Does Superdrol convert to estrogen?
No. Methasterone is not a substrate for aromatase and does not convert to estrogen. This means no aromatase inhibitor is needed for estrogenic gynecomastia, but it also means users get no estrogen-mediated cardiovascular or joint-protective effects, which may worsen lipid profiles and joint discomfort.
Does Trenbolone convert to estrogen?
Trenbolone itself does not aromatize. However, if stacked with testosterone (common practice), the testosterone component does aromatize. Trenbolone is a potent progestin, which can contribute to gynecomastia through a separate hormonal pathway independent of estrogen.
How does Superdrol work for muscle building?
Methasterone binds androgen receptors and increases nitrogen retention and protein synthesis. Preclinical rat bioassay data indicate a high anabolic-to-androgenic ratio relative to methyltestosterone, though these animal-derived ratios do not reliably predict human outcomes.
What are Trenbolone's known side effects?
Documented effects in case reports and observational studies include severe suppression of endogenous testosterone, adverse lipid changes (HDL reduction), left ventricular hypertrophy, androgenic alopecia, aggressive mood changes, insomnia, night sweats, and persistent hypogonadism after cessation. Neurotoxicity has been shown in rodent studies.
Is Superdrol liver toxic?
Yes. As a 17-alpha-alkylated oral steroid, methasterone resists hepatic first-pass metabolism via the C-17 modification, which impairs conjugation and leads to intrahepatic cholestasis. Published case reports describe cholestatic jaundice, elevated transaminases, and at least one case of peliosis hepatis attributed to Superdrol use.
Can you stack Superdrol and Trenbolone?
Some users do combine them, but the combination compounds cardiovascular risk (severe dyslipidemia from two non-aromatizing androgens), does not reduce hepatotoxicity from Superdrol, and adds trenbolone's neuropsychiatric and androgenic burden. There is no human safety or efficacy data for this combination.
Are Superdrol and Trenbolone legal?
In the United States, both are Schedule III controlled substances under the Anabolic Steroid Control Acts. Trenbolone has never been approved for human use by the FDA. Methasterone was sold briefly as a supplement before the DEA scheduled it in 2012. Possession without a prescription is a federal offense.
What does Post Cycle Therapy (PCT) look like after Superdrol or Tren?
Both compounds cause significant suppression of the hypothalamic-pituitary-gonadal axis. Recovery of endogenous testosterone can take months and may be incomplete, particularly after trenbolone. PCT protocols typically involve SERMs such as clomiphene or tamoxifen, but there are no controlled trials confirming these protocols restore fertility or long-term hormonal health.
Which is better for strength, Superdrol or Tren?
No head-to-head human RCT exists. Observational bodybuilding reports consistently rate both as high-potency compounds for strength and mass. Superdrol is often described as producing rapid, water-free strength gains within weeks. Trenbolone is associated with greater body composition changes over a cycle. All comparisons rest on anecdote, not controlled data.
What are safer, evidence-backed alternatives for muscle building?
Progressive resistance training combined with adequate protein intake (1.6 to 2.2 g per kg body weight per day, per meta-analyses) is the only intervention with robust human RCT evidence for lean mass gain without the harm profiles of either compound. Creatine monohydrate has a strong safety profile and consistent RCT support for strength and power output.
Sources
- Jasiurkowski B, Raj J, Wisinger D, Carlson R, Zou L, Nadir A. Cholestatic jaundice and IgA nephropathy induced by OTC muscle building agent Superdrol. Am J Gastroenterol. 2006;101(11):2659-2662.
- Nasr J, Ahmad J. Severe cholestasis and renal failure associated with the use of the designer steroid Superdrol (methasteron): a case report and literature review. Dig Dis Sci. 2009;54(5):1144-1147.
- United States Drug Enforcement Administration. Schedules of Controlled Substances: Placement of methasterone into Schedule III. Federal Register, 2012.
- Anabolic Steroid Control Act of 2004. Pub.L. 108-358. United States Congress.
- Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384.
- World Anti-Doping Agency. Prohibited List 2024. S1 Anabolic Agents. wada-ama.org.
- Parr MK, Schmidtsdorff S, Michels G. Anabolic steroids and the heart: a literature review. Herz. 2020;45(7):683-692. (Reviews cardiovascular effects of anabolic androgens including trenbolone class compounds.)
- Basaria S, Wahlstrom JT, Dobs AS. Clinical review 138: anabolic-androgenic steroid therapy in the treatment of chronic diseases. J Clin Endocrinol Metab. 2001;86(11):5108-5117.
- Hartgens F, Kuipers H. Effects of androgenic-anabolic steroids in athletes. Sports Med. 2004;34(8):513-554.
- Penatti CA, Oberlander JG, Davis MC, Porter DM, Henderson LP. Chronic anabolic androgenic steroid exposure alters corticotropin releasing factor expression and anxiety-like behaviors in the female mouse. Psychoneuroendocrinology. 2011;36(9):1478-1488. (Rodent neuropsychiatric model.)
Footer Disclaimers
Platform: FormBlends is an informational platform. Nothing on this page constitutes medical advice, a diagnosis, or a treatment recommendation. Consult a licensed healthcare provider before making any decisions related to the compounds discussed here.
Research and Legal Status: Methasterone (Superdrol) and trenbolone are Schedule III controlled substances in the United States. Neither has FDA approval for human use. This page does not facilitate, encourage, or endorse the purchase, possession, or use of either compound. Discussing a compound's pharmacology is not an endorsement of its use.
Results Disclaimer: Any anabolic or performance effects attributed to these compounds in this article are drawn from preclinical data, veterinary studies, or uncontrolled human observations. Individual results, if any, vary and are not predicted by this page.
Trademark: "Superdrol" and "Finaplix" are referenced for informational and comparative purposes only. FormBlends has no affiliation with any manufacturer or distributor of these compounds.