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Muscle & performance

Masteron E (Drostanolone Enanthate)

The long-acting masteron variant - the same hardening steroid, injected less often.

1 min read 11 sources

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Glass vial with pale yellow oil and a black TPD label on a white podium, next to it a glossy blue 3D steroid molecule with a long side chain in a bright lab, symbolic image for Drostanolone Enanthate
No study of its own · not approvedLab tested in the shop

Summary

At a glance

Sources checked on 26 Oct 2026

Trials in the registry
0 trials

no trial with drostanolone on ClinicalTrials.gov, as of 25 Oct 202610

Remission in breast cancer
46 %

Drostanolone and two other androgens, 91 patients, 16 weeks, chemotherapy from week 42

Less growth of breast cancer cells
94 %

as propionate, cell culture, highest concentration tested3

Detectable in urine
24 days

Drostanolone after one intramuscular injection, one volunteer, doping research4

  • Drostanolone Enanthate is the same compound as the propionate, 2-alpha-methyl-dihydrotestosterone, just with a long enanthate ester. The compound acts on the androgen receptor.59
  • As the enanthate drostanolone was never approved and never tested in humans. The propionate was approved in the USA as an injection and is no longer marketed there.810
  • On the enanthate itself there are only lab studies: it harmed cancer cells to different degrees but not normal connective tissue cells.1
  • The clinical data on drostanolone come from breast cancer treatment in the 1960s and 1970s. After one injection breakdown products were detectable in urine for up to 24 days.24
  • On side effects there are only reviews of the whole drug class. Everything here is the state of research, not a recommendation.76
Profile

Updated June 2026

How long does it stay in the body?

Share left after one dose, calculated with a half-life of ~6 days

Half-life ~6 days
After 12 days: 25 %
Day 6 · 50 %Day 12 · 25 %Day 18 · 12.5 %Day 30 · 3.1 %

Simplified model without an absorption phase, half-life from the TPD lexicon. The lexicon gives 5 to 7 days, we calculate with the middle.

Class
DHT derivative

long enanthate ester

Use
Intramuscular or subcutaneous

2x per week

Half-life
about 5-7 days
WADA
banned

anabolic

Sizes
3 sizes

200mg/ml, 250mg/ml, 150mg/ml

Contents 14 sections
  1. At a glance
  2. What is Masteron E?
  3. How it works
  4. Propionate vs enanthate
  5. Dosing
  6. What the research shows
  7. Research status
  8. Side effects
  9. Storage
  10. PCT / after coming off
  11. Related compounds
  12. FAQ
  13. Glossary
  14. Sources

What is Masteron E?

Masteron E (Drostanolone Enanthate) is the same active molecule as Masteron P, just with a long enanthate ester. That means less frequent injections (2x per week instead of every other day) at the same effect - the dry, hardening cutting effect of a DHT derivative.

This information is for research and educational purposes only. No medical advice.

How it works

Identical to Masteron P: DHT derivative, no aromatization, weakly anti-estrogenic. Only the kinetics differ due to the longer ester.

Where it acts

Where drostanolone acts

Tap a point or a card. Red = androgen receptor, grey = observed or from reviews of the drug class.

  1. Skeletal muscle

    Agonist at the androgen receptor, direct binding (recorded as propionate)9

    AR
  2. Pituitary

    Anabolic steroids suppress natural hormone production according to a review, sometimes for months7

    Observed in trials
  3. Blood lipids

    Anabolic steroids lower HDL cholesterol according to a review7

    Observed in trials
  4. Skin

    Acne is among the most often self-reported effects according to a review7

    Observed in trials
  5. Kidney and urine

    Breakdown products detectable in urine for up to 24 days4

    Observed in trials

Targets in the ChEMBL database9

Compound PubChem CID 13014314: one recorded mechanism, Agonist, direct binding (recorded in ChEMBL for the propionate).

Androgen receptor
Gene
AR
UniProt
P10275
ChEMBL
CHEMBL1871
Action
Agonist, direct binding (recorded in ChEMBL for the propionate)
Glossy blue 3D molecules flow from a glass droplet towards a transparent ring-shaped structure on light blue fibre bundles
The long ester releases the compound slowly, the target is the androgen receptor. Symbolic image.

Propionate vs enanthate

  • Masteron P (propionate): short, every other day, quickly controllable.
  • Masteron E (enanthate): long, 2x per week, more convenient.

Comparison

Short and long ester

The same compound with another ester and related steroids, as described in the TPD lexicon. Tap a card to open its entry.

Drostanolone, short ester Masteron P (Drostanolone Propionate) AR
Drostanolone, long ester Masteron E (Drostanolone Enanthate) AR
Oral 1-alpha-methyl-DHT Proviron (Mesterolone) AR Testosterone, same ester Testosterone Enanthate AR

Dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts

What the research shows

As with Masteron P: historical anti-estrogenic use in breast cancer, general AAS pharmacology in Kicman (2008) and Hartgens & Kuipers (2004).

Study results

What the trials measured

Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.

Regression in advanced breast cancer2

Share of the 91 patients with remission, average of three equally effective androgens

After 4 weeks2 androgen only
Three androgens on average (one of them drostanolone) 24%
After 16 weeks2 with cyclophosphamide from week 4
Three androgens on average (one of them drostanolone) 46%

Testolactone, drostanolone and nandrolone were compared, with no difference in effect. The drostanolone ester is not given in the abstract, the enanthate was never tested clinically. Historical treatment.

Growth inhibition of breast cancer cells3

Inhibition in percent, MCF-7 cell line, two days of exposure, the propionate was tested

Drostanolone propionate3
Lowest concentration tested 16%
Highest concentration tested 94%

The range spans three orders of magnitude in concentration. Lab experiment with the short ester, not tested in humans.

Glass sculpture of a torso with abdominal muscles, next to it a glass model of a hair follicle, petri dishes and a glass rod on a light background
There are only lab studies on the enanthate. Symbolic image.

Research status

Where the research stands

There are only lab studies on the enanthate. The clinical data on drostanolone predate today's trial registries. As of 25 Oct 2026. 10

  1. Preclinical Cancer cells and normal cells in the lab
  2. Phase 1 no registered trial
  3. Phase 2 no registered trial
  4. Phase 3 no registered trial
  5. Approval not yet
Never approved as the enanthate. Drostanolone was approved in the USA as the propionate, according to the FDA database it is discontinued.10

So far there is no registered trial in humans. 10

Side effects

  • Androgenic (DHT derivative) - hair loss in predisposed individuals, acne.
  • Can lower HDL.
  • HPTA suppression - PCT topic.
  • Barely any estrogen side effects.

Storage

Store the oil solution at room temperature, protected from light - no fridge needed. Out of reach of children.

Four glass vials with golden oil on a white shelf, next to them a folded light blue cloth
Oil solution at room temperature and protected from light, no fridge needed. Symbolic image.

Related

Related compounds

Same receptors or blends with Masteron E (Drostanolone Enanthate): all in the TPD lexicon.

Masteron E (Drostanolone Enanthate)
Masteron P (Drostanolone Propionate) Same compound, short ester Blend 500 (Tren E + Mast E) Contains Drostanolone Enanthate plus trenbolone enanthate Blend 300 (TMT 100/100/100) Contains drostanolone plus trenbolone and testosterone Proviron (Mesterolone) Related methyl-DHT, oral Testosterone Enanthate Testosterone with the same ester Trenbolone Enanthate Trenbolone with the same ester

FAQ

Common questions about Masteron E (Drostanolone Enanthate)

Short answers, each backed by the sources below.

Are there studies on Drostanolone Enanthate?

Only in the lab. In one paper microorganisms converted the enanthate into eight breakdown products that were tested against cancer cells: it harmed the cancer cells to different degrees and was not toxic to normal connective tissue cells. There are no human studies, not on ClinicalTrials.gov either (as of 25 October 2026).110

Is Drostanolone Enanthate approved?

No. Only the propionate was approved in the USA as an injection. According to the FDA database even that is no longer marketed. Neither the FDA nor the ChEMBL database lists the enanthate as a drug.89

What is the difference from the propionate?

The compound is the same, 2-alpha-methyl-dihydrotestosterone. The enanthate carries a longer acid chain than the propionate, which is released more slowly from the oil depot. There are no measured human half-lives for the two esters.511

What was drostanolone used for in the past?

In advanced breast cancer. In a controlled trial from 1978 with 91 patients testolactone, drostanolone and nandrolone worked equally well: on average tumours regressed in 24 percent after 4 weeks and in 46 percent after another 12 weeks with cyclophosphamide. The ester used is not given in the abstract.2

How long is drostanolone detectable?

In a doping research study one volunteer received an intramuscular injection of drostanolone. Two new breakdown products were detectable in urine for up to 24 days, with a simpler method for up to 7 days. The main breakdown product is 2-alpha-methyl-androsterone.45

Which side effects have been described?

There are no studies with frequencies. Reviews of anabolic steroids list increased sexual drive, acne, more body hair and more aggression as the most often self-reported effects. HDL cholesterol also falls, blood pressure can rise and natural hormone production can stay disturbed for months after stopping.76

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

Androgen receptor
Protein inside the cell that androgens bind to. Genes are then read, for example for muscle building.
Aromatization
Conversion of an androgen to estrogen by the enzyme aromatase.
Cutting
Diet phase aiming to lose fat while keeping muscle.
DHT
Dihydrotestosterone, a strong androgen made from testosterone in the body. It cannot be converted to estrogen.
Enanthate ester
Long acid chain on the compound. It makes it oil-soluble and releases it more slowly from the depot than a short ester.
HDL cholesterol
Cholesterol carrier that takes fat from the vessels to the liver. Low levels are considered unfavourable for the heart and vessels.
Hormone axis (HPTA)
Hypothalamus, pituitary and testes together control the body's own testosterone production. Anabolic steroids from outside suppress this axis.
PCT
Post cycle therapy, the phase after stopping in which natural hormone production is meant to restart.
Propionate ester
Short acid chain on the compound, released faster than long esters.
Remission
Regression of a disease, in cancer a shrinking or disappearance of tumours.

Practice

PCT / after coming off

Anabolic substances suppress the body's own testosterone production in the research context. Anyone who comes off a cycle (rather than running it continuously) typically uses a post-cycle therapy (PCT) to restart the natural axis (HPTA).

The standard scheme in the research/literature context combines a SERM (tamoxifen and/or clomifene, alternatively enclomiphene) over roughly four weeks, optionally preceded by HCG to re-sensitise the testes before the SERM block. An aromatase inhibitor (anastrozole/exemestane) belongs more to on-cycle estrogen control than to the PCT itself.

Tip: order the PCT items together with the cycle so they are already on hand when you come off.

This information serves research and educational purposes only. Not medical advice.

Tamoxifen (Nolvadex) SERM, core of PCT View Clomid (Clomifen) SERM, core of PCT View Enclomiphene (Androxal) SERM alternative View HCG testicular restart before PCT View Arimidex (Anastrozole) aromatase inhibitor, on-cycle View Aromasin (Exemestane) aromatase inhibitor, on-cycle View

Evidence

Sources

Show all 11 sourcesHide sources 7 Studies1 Trial registry3 Database checked 26 Oct 2026

Studies

  1. Drostanolone enanthate: breakdown by microorganisms and effect on cancer cells

    Choudhary et al., Frontiers in Pharmacology, 2017

    DOI 10.3389/fphar.2017.00900 PMID 29326586
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  2. Controlled trial: three androgens in advanced breast cancer

    Wolff und Rieche, Onkologie, 1978

    DOI 10.1159/000213943 PMID 362297
    Checked 26 Oct 2026 via doi.org, Crossref (Online-Jahr 2009), PubMed
  3. MCF-7 breast cancer cells with drostanolone propionate and 5-fluorouracil

    Fujita et al., European Journal of Cancer and Clinical Oncology, 1983

    DOI 10.1016/0277-5379(83)90200-6 PMID 6688585
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  4. Breakdown products of drostanolone in urine

    Liu et al., Steroids, 2016

    DOI 10.1016/j.steroids.2016.01.013 PMID 26826321
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  5. Structure and breakdown of mesterolone and drostanolone

    de Boer et al., Journal of Steroid Biochemistry and Molecular Biology, 1992

    DOI 10.1016/0960-0760(92)90146-a PMID 1606052
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  6. Review of the pharmacology of anabolic steroids

    Kicman, British Journal of Pharmacology, 2008

    DOI 10.1038/bjp.2008.165 PMID 18500378
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  7. Review: effects and side effects of anabolic steroids in athletes

    Hartgens und Kuipers, Sports Medicine, 2004

    DOI 10.2165/00007256-200434080-00003 PMID 15248788
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. Search on ClinicalTrials.gov

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

Database

  1. US approval of the propionate (NDA 012936), discontinued

    Drugs@FDA, U.S. Food and Drug Administration

    Checked 26 Oct 2026 via openFDA-API
  2. Mechanism of drostanolone propionate in ChEMBL

    ChEMBL, EMBL-EBI (CHEMBL1201048)

    Checked 26 Oct 2026 via ChEMBL
  3. Structure of Drostanolone Enanthate in PubChem

    PubChem, U.S. National Library of Medicine (CID 13014314)

    Checked 26 Oct 2026 via PubChem

In the shop

Masteron E (Drostanolone Enanthate) in the catalog

Sizes, prices and shipping times are on the product page.

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