Dymethazine, also spelled dimethazine and known by the international nonproprietary name mebolazine, is an oral anabolic steroid made of two methasterone molecules joined by a nitrogen bridge. Methasterone is the steroid once sold as “Superdrol.” Dymethazine was described by Italian researchers in the early 1960s, then resurfaced around 2012–2014 as “DMZ” in products sold as dietary supplements.
The single most important fact: no controlled human trial of dymethazine is available to review, and there are no human pharmacokinetic data. What is documented in the modern literature is that it breaks down to methasterone in laboratory and animal models, that it has turned up in supplements (including hidden in vitamin products), and that a dymethazine-containing product was linked to severe cholestatic jaundice in a young man.
This page summarizes what laboratory studies, case reports and regulators report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Class | Designer anabolic-androgenic steroid; azine-linked dimer of methasterone |
| Other names | Dimethazine, mebolazine (INN), DMZ; PubChem also lists the name Roxilon |
| Formula / weight | C₄₂H₆₈N₂O₂, 633.0 g/mol |
| Route | Oral |
| Studied human doses | None from controlled trials. One supplement linked to liver injury listed 10 mg per capsule |
| Half-life | No published human data |
| Active form | Breaks down to methasterone (stability study, human liver microsomes, mice with humanized livers) |
| US status | Not named in the federal anabolic steroid list; its parent, methasterone, is Schedule III. The 2014 designer steroid law may apply |
| WADA status | Not named, but prohibited at all times under S1.1; detected through methasterone metabolites |
What it is
Dymethazine’s chemical name is 17β-hydroxy-2α,17α-dimethyl-5α-androstan-3-one azine (PubChem). An azine is a C=N–N=C link. Here it joins the 3-keto carbon of one methasterone molecule to the 3-keto carbon of a second one, so the compound is essentially two methasterone units back to back (Geldof et al., Biomed Chromatogr 2016; Joseph and Parr, Curr Neuropharmacol 2015).
| Compound | Formula | Molecular weight | Relationship |
|---|---|---|---|
| Methasterone | C₂₁H₃₄O₂ | 318.5 g/mol | Parent steroid (PubChem) |
| Dymethazine | C₄₂H₆₈N₂O₂ | 633.0 g/mol | Two methasterone units linked through C3 by an azine bridge |
Methasterone itself is a DHT (dihydrotestosterone) derivative with two added methyl groups:
- a 17α-methyl group, the feature shared by orally active steroids such as methyltestosterone;
- a 2α-methyl group, the same change that turns DHT into drostanolone (Masteron).
DEA’s 2012 scheduling rule states that removing testosterone’s 4,5 double bond and adding methyl groups at C2 and C17 has been shown to increase anabolic activity. It also notes that methasterone was first synthesized in 1956 and was described as a potent anabolic with weak androgenic activity in castrated male rats (DEA, 77 FR 44456). That is animal data on the parent compound, not on dymethazine in people. For the parent drug, see the Superdrol (methasterone) page.
About potency claims. Supplement marketing has described DMZ as a “mild” or “dry” steroid with a specific anabolic:androgenic ratio. We found no primary assay of dymethazine in the accessible literature that supports such figures, so we do not repeat them. The modern evidence shows only that it converts to methasterone.
Early history
Dymethazine was first described in Italian journals as a “proteo-anabolic” steroid, meaning one intended to promote protein build-up (De Ruggieri et al., Arch Sci Biol 1963). Through the 1960s it was tried in a range of clinical settings, judging by the titles of published reports:
| Year | Setting | Report |
|---|---|---|
| 1962 | Patients with genital cancers during radiotherapy | Fontana Donatelli and Dambrosio |
| 1963 | Pulmonary tuberculosis | Masserini and Berloco |
| 1964 | Weight-loss syndromes | Innerhofer |
| 1964 | Underdeveloped children and adolescents | Chavezmontes |
| 1966 | Osteoporosis | Mastrorilli |
| 1966 | Fracture healing | Mastrorilli |
These are Italian- and Spanish-language papers with no abstracts in PubMed. We could not review their design, size, doses or results, so they show only that the drug was used clinically in that era, not that it worked or was safe.
How it works in the body
There are no human pharmacokinetic studies of dymethazine, so its absorption, peak levels and half-life in people are unknown.
The key modern study came from the Ghent doping control laboratory, which examined a product sold as “Xtreme DMZ” (Geldof et al., Biomed Chromatogr 2016). Because giving designer steroids to volunteers raises ethical problems, the team used two substitutes for human dosing:
- human liver microsomes (enzyme preparations from human liver tissue, in vitro);
- uPA+/+-SCID chimeric mice, whose livers are largely repopulated with human liver cells.
The findings:
- In a stability study, dymethazine degraded to methasterone.
- In both models, the parent compound, methasterone and six further metabolites (M1–M6) were detected. All six were methasterone metabolites.
- In the mouse urine, two metabolites appeared only as glucuronide conjugates; the rest also appeared in free form.
- The authors concluded that screening for methasterone and its metabolites should be enough to detect dymethazine use in doping tests.
In practical terms, the available evidence suggests dymethazine acts as a carrier, or prodrug, for methasterone. This is inferred from laboratory and mouse data; it has not been confirmed in a human dosing study.
Regulatory status
United States
- Methasterone has been a Schedule III anabolic steroid since August 29, 2012 (DEA, 77 FR 44456) and is named in the federal list (21 CFR 1308.13).
- Dymethazine is not named in that list. A 2014 case report described it as not a controlled substance at the time (Agbenyefia et al., 2014).
- The Designer Anabolic Steroid Control Act of 2014 added a clause covering unlisted substances that are “derived from, or” have “a chemical structure substantially similar to” a listed anabolic steroid. Such a substance counts as an anabolic steroid if it was made to promote muscle growth or testosterone-like effects, or is marketed that way (Public Law 113-260). We found no DEA order or court decision applying this clause to dymethazine by name.
Sport
The WADA 2026 Prohibited List names methasterone under S1.1 (anabolic androgenic steroids), which are prohibited at all times. S1.1 also covers “other substances with a similar chemical structure or similar biological effect(s).” Dymethazine is not named, but it is built from methasterone and is detected through methasterone metabolites, so athletes should treat it as prohibited.
What the research shows
No randomized or controlled human trial of dymethazine on muscle, strength or any medical outcome is available. The 1960s clinical reports listed above could not be evaluated. There is therefore no evidence base from which to state an effective or safe dose.
The modern literature on dymethazine consists of:
- one metabolism study in laboratory and mouse models (above);
- one case report of liver injury;
- one chemical analysis linking it to a cluster of illnesses;
- reviews of designer steroids in supplements.
Side effects and risks
Cholestatic liver injury: case report
A 26-year-old previously healthy man took Super DMZ Rx 2.0, a product listing 10 mg methylstenbolone and 10 mg dymethazine per capsule, at 1 capsule twice daily for 30 days (Agbenyefia et al., 2014). About 3 weeks in he noticed dark urine and pale stools, and he became jaundiced by the end of week 4. Viral hepatitis tests and imaging of the bile ducts were negative.
His liver tests, counted from the first day of use:
| Day | ALT (IU/L) | ALP (units/L) | Total bilirubin (mg/dL) |
|---|---|---|---|
| Reference range | 10–40 | 44–147 | 0.3–1.9 |
| 35 | 269 | 132 | 19.3 |
| 42 | 167 | 112 | 21.8 |
| 55 | 121 | 218 | 32.0 |
| 59 | 77 | 207 | 45.9 |
| 89 | 174 | 268 | 17.6 |
| 110 | 119 | 146 | 2.1 |
A liver biopsy showed canalicular and hepatocellular cholestasis (bile backed up inside and between liver cells) with little inflammation and no fibrosis. The authors note that this “bland cholestasis” is the characteristic pattern of liver injury from anabolic steroids. Bilirubin was back near normal about 10 weeks after he stopped.
Two limits apply. The product also contained methylstenbolone, another designer steroid, so the injury cannot be pinned on dymethazine alone. The patient also reported past heavy episodic drinking, although his last drink was about 45 days before he presented.
Hidden in vitamin supplements
In 2012–2013, about 16 New York residents reported fatigue, scalp hair loss and muscle aches after taking B-50 vitamin and multimineral supplements from the same supplier (Tran et al., Steroids 2023). State laboratory analysis of the implicated lots found:
- methasterone;
- dimethazine;
- methylstenbolone.
Methasterone and some capsule extracts were strongly androgenic in cell-based androgen receptor assays. The contaminated lots were associated with one hospitalization for liver damage and with severe virilization (development of male traits) in a child. None of these ingredients were declared.
What to expect from the parent steroid
Because dymethazine appears to release methasterone, the parent compound’s record is relevant. DEA’s scheduling rule cites published reports of liver toxicity with kidney failure in people using methasterone, and notes that FDA issued a warning letter in March 2006 over adverse effects of the product Superdrol (DEA, 77 FR 44456).
Reviews of designer steroids sold over the counter report these harms across the group (Rahnema et al., Andrology 2015):
- liver toxicity and cholestasis;
- kidney failure;
- hypogonadism (shutdown of the body’s own testosterone production);
- gynecomastia (breast tissue growth in men);
- infertility.
No study has measured these outcomes for dymethazine specifically.
Product quality
Dymethazine has no approved, quality-controlled source we could identify. Products are sold outside pharmaceutical regulation, may contain other steroids (as in both reports above), and may not declare their steroid content at all.
Key takeaways
- Two methasterone molecules in one. Dymethazine is an azine-linked dimer of methasterone (Superdrol), and in laboratory and humanized-liver mouse models it breaks down to methasterone.
- No human trial data. No controlled study of its effects, dose or half-life in people is available; the 1960s Italian reports could not be evaluated.
- Linked to serious liver injury. A product containing dymethazine and methylstenbolone was followed by deep jaundice, with bilirubin peaking at 45.9 mg/dL, in a healthy 26-year-old.
- Found hidden in vitamins. New York investigators found it with methasterone and methylstenbolone in B-vitamin supplements tied to illness and a child’s virilization.
- Legal gray zone, but banned in sport. It is not named in the US steroid schedule, though its parent is Schedule III and the 2014 designer steroid law may reach it; WADA prohibits it under S1.1.
Sources
- National Center for Biotechnology Information. Mebolazine (dymethazine), PubChem CID 66847280. PubChem.
- National Center for Biotechnology Information. Methasterone, PubChem CID 237186. PubChem.
- De Ruggieri P, Matscher R, Gandolfi C, et al. [A new steroid having proteo-anabolic action: dimethazine]. Arch Sci Biol (Bologna). 1963;47:1–19. PubMed.
- Fontana Donatelli G, Dambrosio F. [Clinical evaluation of the proteo-anabolic activity of dimethazine in patients with genital neoplasms during actinotherapy]. Ann Ostet Ginecol. 1962;84:773–783. PubMed.
- Masserini C, Berloco N. [Research on the metabolic activity of dimethazine in the patient with pulmonary tuberculosis]. Minerva Med. 1963;54:1685–1691. PubMed.
- Innerhofer O. [Dimethazine and syndromes with loss of weight]. Gazz Med Ital. 1964;123:326–332. PubMed.
- Chavezmontes J. [Use of dimethazine in underdeveloped children and adolescents]. Rev Iber Endocrinol. 1964;11:225–232. PubMed.
- Mastrorilli A. [Synthetic anabolic steroids (dimethazine) in osteoporosis]. Minerva Ortop. 1966;17(7):399–401. PubMed.
- Mastrorilli A. [The action of “dimethazine” in the consolidation of fractures]. Minerva Ortop. 1966;17(3):178–184. PubMed.
- Geldof L, Tudela E, Lootens L, et al. In vitro and in vivo metabolism studies of dimethazine. Biomed Chromatogr. 2016;30(8):1202–1209. PubMed.
- Joseph JF, Parr MK. Synthetic androgens as designer supplements. Curr Neuropharmacol. 2015;13(1):89–100. PMC.
- Agbenyefia P, Arnold CA, Kirkpatrick R 3rd. Cholestatic jaundice with the use of methylstenbolone and dymethazine, designer steroids found in Super DMZ Rx 2.0 “nutritional supplement”: a case report. J Investig Med High Impact Case Rep. 2014;2(2):2324709614532800. PMC.
- Tran BN, Okoniewski R, Spink BC, et al. Androgenic steroids in over-the-counter dietary supplements: analysis for association with adverse health effects. Steroids. 2023;193:109199. PubMed.
- Rahnema CD, Crosnoe LE, Kim ED. Designer steroids - over-the-counter supplements and their androgenic component: review of an increasing problem. Andrology. 2015;3(2):150–155. PubMed.
- Drug Enforcement Administration. Classification of two steroids, prostanozol and methasterone, as Schedule III anabolic steroids under the Controlled Substances Act. Final rule. Federal Register. July 30, 2012;77(146):44456–44462 (FR Doc 2012-18495). Federal Register.
- Designer Anabolic Steroid Control Act of 2014. Public Law 113-260, 128 Stat. 2929. December 18, 2014. govinfo.
- Code of Federal Regulations. Title 21, §1308.13, Schedule III. 21 CFR 1308.13.
- World Anti-Doping Agency. The 2026 Prohibited List. In effect January 1, 2026. WADA 2026 Prohibited List.