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Muscle & performance

Sustanon 250

The classic testosterone ester mix: four different esters in one oil, combining fast and long duration.

2 min read 14 sources

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Several glossy blue 3D steroid molecules with side chains of different length above a white podium with a glowing light-blue ring, symbolic image for Sustanon 250
Approved · as a four-ester medicine

Summary

At a glance

Sources checked on 25 Oct 2026

In one blend
4 esters

Propionate, phenylpropionate, isocaproate and decanoate, each detectable in blood, each for a different length of time2

Protein gain in muscle
+8.3 g per day

Older men with strength training over 6 weeks, +1.9 g with placebo and training5

Lumbar spine bone density
+5 %

21 men with osteoporosis, 6 months, injection every 2 weeks, open study6

Esters detectable in blood
14 days

Dried blood spots: all esters for at least 5 days, three of the four for up to 14 days4

  • Sustanon 250 blends four testosterone esters in one oil. Short esters reach the blood quickly while long ones hold the level. All four release the same compound, which acts on the androgen receptor.214
  • In older men with strength training the blend raised fat-free mass, muscle thickness and strength more than training alone within 6 weeks while fat mass fell.5
  • In two studies lumbar spine bone density rose by about 5 percent, in men with osteoporosis and in men taking cortisone.67
  • The body's own hormone axis is suppressed: LH and testicular markers fell in young men and recovered after stopping. Red blood cell values shift.83
  • The four-ester blend appears in phase 4 trials on the registry, so it is in use as a medicine. Everything here is the state of research, not a recommendation.13
Profile

Updated May 2026

Class
Testosterone ester mix

anabolic steroid

Use
Intramuscular

oil, in mg/week

Contents
4 test esters

250mg/ml total

WADA
Banned

category S1

Sizes
10 ml

1 size in the shop

Contents 15 sections
  1. At a glance
  2. What is Sustanon 250?
  3. How it works
  4. Use
  5. Dosing
  6. What the research shows
  7. Research status
  8. Side effects
  9. Practice
  10. Storage
  11. PCT / after coming off
  12. Related compounds
  13. FAQ
  14. Glossary
  15. Sources

What is Sustanon 250?

Sustanon 250 is a ready-made oil that combines four different testosterone esters in one ml (250mg together). The esters differ in duration: short esters act fast, long esters keep a sustained level. So the effect kicks in early and still lasts longer.

Important: this is an anabolic steroid, not a peptide. It is not reconstituted but ready to use.

Comparison

One ester or four

The same compound at the same receptor with esters of different length, as stated in the TPD lexicon. Tap a card to open its entry.

Short ester, part of the blend Testosterone Propionate AR Medium ester, part of the blend Testosterone Phenylpropionate AR Very long ester, part of the blend Testosterone Decanoate AR
Four esters blended Sustanon 250 AR
Long single ester Testosterone Enanthate AR

Simplified: the ester only sets how fast testosterone is released from the depot. At the receptor it is always the same testosterone. 211

How it works

All four esters release the same compound: testosterone. In the body it binds the androgen receptor and drives muscle growth, strength and male hormone effects. The ester mix is just a release trick: propionate acts fast, decanoate long, with phenylpropionate and isocaproate in between.

Testosterone aromatizes to estrogen, so an aromatase inhibitor can become relevant (see anastrozole/exemestane).

Where it acts

Where the blend acted in studies

Tap a point or a card. Grey = observed in studies, all via the androgen receptor.

  1. Pituitary

    LH fell in young men, back to baseline after stopping8

    Observed in trials
  2. Testes

    Leydig cell marker INSL3 fell, recovered after stopping8

    Observed in trials
  3. Skeletal muscle

    More fat-free mass, muscle thickness and strength than with training alone5

    Observed in trials
  4. Fat tissue

    Total fat mass fell within 6 weeks5

    Observed in trials
  5. Bone

    Spine bone density +5 percent, bone breakdown slowed6

    Observed in trials
  6. Blood

    Red blood cell values shifted, more young red blood cells3

    Observed in trials

Targets in the ChEMBL database14

Compound CHEMBL386630: one recorded mechanism, Agonist, direct binding (testosterone).

Androgen receptor
Gene
AR
UniProt
P10275
ChEMBL
CHEMBL1871
Action
Agonist, direct binding (testosterone)
Translucent glass muscle fibres with docking sites where blue steroid molecules dock one wave after another
Esters of different length release testosterone at staggered times; it acts on the androgen receptor. Symbolic image.

Use

Dosing. Loading the dosing information …
Small glass vial with clear, slightly yellowish oil and a grey stopper on a white tray, a capped syringe beside it
Ready-to-use oil solution, no mixing. Symbolic image.

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

Testosterone esters are well established as hormone replacement. The anabolic pharmacology is broadly described (for context e.g. Yarrow, 2010, on tissue selectivity of anabolic steroids). Performance doses far above the TRT range are not covered by controlled studies. Risk rises with the dose.

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.

Protein gain in muscle per day5

Older men (65 to 75 years), 6 weeks of strength training, injection every 2 weeks, 9 participants each

Randomised double-blind trial5 Net gain from synthesis minus breakdown
Placebo with training +1.9 g
Testosterone blend +8.3 g

Muscle protein synthesis ran at 2.13 percent per day with the blend and 1.34 percent with placebo. Breakdown rose too, but on balance clearly more protein stayed in the muscle.

Lumbar spine bone density67

Change in percent on the blend

Men with osteoporosis6 21 men, 6 months, no comparison group
Testosterone blend +5.0%
Men on cortisone7 15 men with asthma, 12 months, crossover
Testosterone blend +5.0%

Abstract values 5 and 5.0 percent. In the cortisone study bone density did not change without testosterone; in the control phase fat mass rose and lean mass fell, both reversed with testosterone.

Flagged profiles after two injections3

Share of the 9 men on the blend, randomised against placebo

Healthy men3 Measurements 1 to 14 days after each injection
Steroid profile flagged 100.0%
Blood profile flagged 66.7%

Steroid profile flagged in 9 of 9, blood profile in 6 of 9 (shown as a share). The share of young red blood cells (reticulocytes) showed the use best, mainly 3 to 10 days later.

Translucent glass muscle fibre bundle circled by four light trails of different length
Four esters, four release times. Symbolic image.

Research status

Where the research stands

Registered trials with the four-ester blend, mostly as testosterone replacement in hormone deficiency. As of 25 Oct 2026. 13

  1. Preclinical Animal model (rats): testes and sperm production
  2. Phase 1 1 trial, 0 completed
  3. Phase 2 no registered trial
  4. Phase 3 1 trial, 1 completed
  5. Approval as a four-ester medicine
0 participants in phase 3 In use as a medicine: the registry lists phase 4 trials with exactly this four-ester blend. ChEMBL lists testosterone and testosterone propionate as approved drugs.13
Show all 13 trials on a timelineHide timeline 12 completed 1 running 0 with results
Phase 3
Phase 4
Without phase

Bar: start to primary endpoint (planned for running trials). Green = completed, blue = progress until 25 Oct 2026. Phase 1: 1 trial on safety and pharmacokinetics, not shown as bars.

Side effects

  • Estrogen-related: water retention, gyno risk (aromatization).
  • Suppression of the body's own testosterone production, testicular shrinkage.
  • Negative lipid shift, acne, possible blood pressure rise.
  • With longer/higher use, keep an eye on heart and liver strain.

Practice

  1. Blood values (testosterone, estradiol, hematocrit, lipids) before and during a cycle.

  2. Aromatase inhibitor only as needed and to bloodwork, not blind.

  3. Plan a post-cycle.

  4. Banned in official competition (WADA S1).

Calm still life on a light wooden shelf: dumbbells, a glass of water, a closed notebook with a pen and empty sample tubes in morning light

Storage

Store the oil at room temperature, cool and protected from light, out of reach of children. Keep the original bottle closed and mind the expiry date.

Four glass vials with golden oil on a white shelf, a folded light-blue cloth beside them
Oil at room temperature, dark and closed. Symbolic image.

Related

Related compounds

Same receptors or blends with Sustanon 250: all in the TPD lexicon.

Sustanon 250
Sustanon 300 Same idea, more concentrated Sustanon 400 Same idea, even more concentrated Supertest 450 Several esters, very highly concentrated Test Mix (high dose) Four esters, highly concentrated Tri-Test Three esters instead of four Testosterone Propionate Short ester on its own Testosterone Phenylpropionate Medium ester on its own Testosterone Decanoate Very long ester on its own Testosterone Enanthate Long single ester, best studied

FAQ

Common questions about Sustanon 250

Short answers, each backed by the sources below.

Why four esters in one injection?

Each ester is released from the oil depot at a different speed. After a single injection of the blend all four esters were detectable in blood and how long depended on the ester. A short ester like propionate kept levels above the normal range for about 48 hours in one study while long esters last much longer. At the receptor it is always testosterone in the end.210

Is Sustanon 250 approved?

The four-ester blend is used as a medicine: ClinicalTrials.gov lists several phase 4 trials with it, meaning trials after approval, mostly on testosterone replacement in hormone deficiency. The ChEMBL database lists testosterone and testosterone propionate as approved drugs. It is banned in sport. Everything here is the state of research, not a recommendation.1314

What did the study in older men show?

18 healthy men aged 65 to 75 did 6 weeks of weight training and got the blend or placebo every 2 weeks. With testosterone fat-free mass, leg mass, muscle thickness and strength rose more while fat mass fell. Net protein gain in muscle was 8.3 g per day versus 1.9 g with placebo. The study ran for only 6 weeks with 9 people per group.5

Does the blend affect bone?

In two small studies lumbar spine bone density rose by about 5 percent: in 21 men with osteoporosis over 6 months and in 15 men on long-term cortisone for asthma over 12 months. Bone breakdown slowed. In the osteoporosis study estradiol also rose by 45 percent. That was what tracked the bone gain.67

What happens to the body's own hormone production?

Testosterone from outside suppresses the hormone axis. In healthy young men LH and the testicular marker INSL3 fell on the blend and returned to baseline after stopping. In a rat study the testes shrank and sperm count, LH and FSH fell.89

How long do the esters stay in the blood?

In dried blood spots all four esters were measurable for at least 5 days after two injections and three of them for up to 14 days. Blood values changed too: the blood profile was flagged in 6 of 9 men, most clearly the share of young red blood cells 3 to 10 days after the injection.43

Which risks are known?

The Endocrine Society describes a higher risk of cardiovascular, liver, kidney, hormonal and psychiatric disorders for performance-enhancing drugs in high amounts. Controlled trials with such amounts hardly exist for ethical reasons. With the blend itself red blood cell values rise and the body's own hormone axis is suppressed.1238

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

Androgen receptor
Protein inside the cell that testosterone binds to. Genes are then read, for example for muscle building.
Aromatase
Enzyme that converts part of the testosterone into estradiol.
Bone density
Mineral content of bone, measured by X-ray (DXA). Low values mean osteoporosis.
Decanoate
The longest of the four esters. It holds the level the longest.
Ester
An attached fatty acid chain. It makes testosterone oil-soluble and sets how slowly it is released from the depot. It is split off in the blood.
Hormone axis (HPTA)
Hypothalamus, pituitary and testes together control the body's own testosterone production. Testosterone from outside suppresses this axis.
INSL3
Hormone from the Leydig cells in the testes. It shows how active the body's own testosterone production is.
Intramuscular
Into the muscle, for example the glute or thigh.
LH
Pituitary hormone that drives testosterone production in the testes. Testosterone from outside lowers it.
Placebo
Dummy preparation without active substance. Comparing against it shows what is due to the substance itself.
Propionate
The shortest of the four esters. It reaches the blood quickly and is gone quickly.
Reticulocytes
Young red blood cells. If their share rises, the bone marrow is making more blood.

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 14 sourcesHide sources 12 Studies1 Trial registry1 Database checked 25 Oct 2026

Studies

  1. Trenbolone review as a reference for the pharmacology of anabolic steroids (tissue selectivity)

    Yarrow et al., Steroids, 2010

    DOI 10.1016/j.steroids.2010.01.019 PMID 20138077
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  2. Detection of the four esters in blood after one injection

    Forsdahl et al., Drug Testing and Analysis, 2015

    DOI 10.1002/dta.1914 PMID 26695486
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  3. Blood values after two injections, randomised against placebo

    Solheim et al., Drug Testing and Analysis, 2020

    DOI 10.1002/dta.2803 PMID 32307878
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  4. Esters in dried blood spots

    Solheim et al., Drug Testing and Analysis, 2022

    DOI 10.1002/dta.3030 PMID 33733610
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  5. Older men, strength training with or without the testosterone blend

    Gharahdaghi et al., Journal of Cachexia, Sarcopenia and Muscle, 2019

    DOI 10.1002/jcsm.12472 PMID 31568675
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  6. Men with osteoporosis, bone density and bone turnover

    Anderson et al., Journal of Bone and Mineral Research, 1997

    DOI 10.1359/jbmr.1997.12.3.472 PMID 9076591
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  7. Men on cortisone, bone and body composition

    Reid et al., Archives of Internal Medicine, 1996

    DOI 10.1001/archinte.1996.00440100065008 PMID 8639011
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed (Titel und Seiten, Datensatz ohne DOI)
  8. INSL3, testosterone and LH with a suppressed hormone axis

    Albrethsen et al., Journal of Clinical Endocrinology and Metabolism, 2023

    DOI 10.1210/clinem/dgad291 PMID 37235781
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  9. Sperm production on the blend (rats)

    Kamali Hosseinzadeh et al., Translational Andrology and Urology, 2024

    DOI 10.21037/tau-24-397 PMID 39816223
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  10. Level over time after testosterone propionate

    Fujioka et al., Journal of Clinical Endocrinology and Metabolism, 1986

    DOI 10.1210/jcem-63-6-1361 PMID 3782423
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  11. Release profile rather than total dose (primates)

    Weinbauer et al., Journal of Andrology, 2003

    DOI 10.1002/j.1939-4640.2003.tb02739.x PMID 12954670
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed
  12. Endocrine Society statement on health consequences

    Pope et al., Endocrine Reviews, 2014

    DOI 10.1210/er.2013-1058 PMID 24423981
    Checked 25 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. Trials with the blend on ClinicalTrials.gov

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

    Checked 25 Oct 2026 via ClinicalTrials.gov API v2

Database

  1. Mechanism and approval of testosterone in ChEMBL

    ChEMBL, EMBL-EBI (CHEMBL386630, Propionat CHEMBL1170)

    Checked 25 Oct 2026 via ChEMBL

In the shop

Sustanon 250 in the catalog

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