Sustanon
Sustanon 250 · Sustanon 350 · Sust · Sust 250 · Sust 350 · Omnadren · Testosterone Blend
Sustanon 250 is a long-standing prescription testosterone product that combines four different testosterone esters in a single oil-based intramuscular injection: testosterone propionate 30mg, testosterone phenylpropionate 60mg, testosterone isocaproate 60mg, and testosterone decanoate 100mg, totalling 250mg of testosterone per millilitre. It is a legitimate, licensed testosterone-replacement therapy (TRT) widely used in Europe, the United Kingdom, and many other countries, marketed by Aspen (originally Organon). 'Sustanon 350' and 'Omnadren' refer to the same multi-ester blend concept at a different concentration or ester ratio - the 250 vs 350 difference is purely the milligrams of testosterone per millilitre, not a different drug; concentration is set per inventory item.
Starting dose. 100-200mg/week — (TRT) | 250-500mg/week (athletic)
Despite the label's roughly-3-weekly schedule, the short propionate/phenylpropionate esters mean levels peak then trough on a long interval. Split the weekly total into 2 injections (e.g. Monday/Thursday) for stable blood levels. The fast esters can cause more post-injection flare/soreness than a pure long ester. Compatible with other oil-based AAS in the same IM syringe.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
Sustanon delivers testosterone, the endogenous reference androgen, which binds the androgen receptor (AR) in skeletal muscle, brain, reproductive tissue, bone, skin, and other target organs to drive androgenic (masculinizing) and anabolic (protein-synthesis, nitrogen-retention) effects. By definition testosterone has a balanced 1:1 anabolic-to-androgenic ratio.
All four esters are pro-drug forms: tissue and plasma esterases cleave the ester bond to release identical free testosterone. The only difference between the esters is the rate of release determined by ester chain length and lipophilicity. Propionate (3-carbon) and phenylpropionate (a phenyl-substituted propionate) release fastest, isocaproate (a branched 6-carbon) is intermediate, and decanoate (10-carbon) is the slowest. The combined depot therefore produces an early rise from the short esters layered on top of a slow sustained release from the decanoate.
Like all testosterone, the released hormone is a substrate for aromatase (converting to estradiol, producing estrogenic effects beneficial and unwanted) and for 5-alpha-reductase (converting to dihydrotestosterone, driving classical androgenic effects on hair, skin, and prostate). At any supraphysiologic dose, endogenous testosterone production through the hypothalamic-pituitary-testicular (HPT) axis is suppressed. An aromatase inhibitor is used when estradiol runs above the physiologic range (common at athletic doses, sometimes unnecessary at TRT doses), and HCG is used to preserve testicular function and fertility.
What to expect
First 1-2 weeks: the fast esters lift testosterone quickly, giving early libido/energy/mood improvement (and sometimes post-injection soreness). Strength gains begin to appear toward the end of week 3.
Weeks 3-8: long esters reach steady state; full physiological effect, visible mass gains, strength plateau. Blood-work checkpoint - estradiol, hematocrit, lipids.
Weeks 8-16: sustained benefits. TRT is typically lifelong; athletic cycles run 12-16 weeks then transition to PCT or cruise.
Evidence
References for this compound are being re-checked against their source records. We are not showing them until each one is confirmed to support the claim it sits under.
Side effects & safety
Commonly reported
- Elevated hematocrit (polycythemia risk)
- Aromatization to estradiol - water retention, possible gyno without AI at athletic doses
- Post-injection soreness/flare (more likely than with a pure long ester, due to the propionate fraction)
- Acne and oily skin
- Accelerated hair loss in genetically predisposed users
- Suppression of endogenous testosterone production
Less common & notes
- Mood changes (positive or negative), sleep apnea exacerbation, lipid shift (HDL drop, LDL rise), cardiac strain at very high doses, prostate enlargement in older men (monitor PSA), gynecomastia if estrogen uncontrolled.
- Women using testosterone for masculinizing HRT: expected virilization (voice deepening, facial/body hair, clitoral enlargement, menstrual cessation) - intended in HRT context, a side effect in cycling context.
- Rare but serious: thromboembolic events from polycythemia, significant cardiac events at supraphysiologic long-term use, severe acne or hair loss, rare anaphylactic reaction to the arachis (peanut) oil vehicle used in the licensed product.
Pharmacokinetics
Mixed: propionate ~0.8 day, phenylpropionate ~1.5 days, isocaproate ~4 days, decanoate ~7-9 days; effective blended duration ~15-18 days
Driven by the short propionate/phenylpropionate esters
Up to ~3 weeks (decanoate ester); detectable washout 3-4+ weeks
IM (oil depot); high via deep SubQ depot
Mixed-release: fast esters act within days, decanoate sustains up to ~3 weeks. Despite the long tail, split 2x/week dosing is preferred for stable levels.
Hepatic metabolism (CYP3A4, CYP2C9); ester bonds cleaved by tissue/plasma esterases to release free testosterone. Aromatization to estradiol and 5-alpha-reduction to DHT are major pathways.
Storage. Store at controlled room temperature (15-30°C / 59-86°F per the licensed label). Protect from light. Oil-based solution (arachis/peanut oil with benzyl alcohol in the licensed product) - do not refrigerate or freeze (may precipitate or thicken). Draw with a larger-gauge needle and inject with a smaller one (18G draw, 23-25G inject for IM; deeper SubQ uses 27-29G at lower volumes). Note the peanut-oil vehicle if the user has a peanut allergy. Keep out of reach of children and in a locked location - Schedule III controlled substance in the United States.
Regulatory status
Schedule III controlled substance in the United States under the Anabolic Steroids Control Act of 1990 (no FDA-approved Sustanon product is marketed in the US; it is imported/compounded or sourced illicitly there). In Europe and the United Kingdom it is a licensed, marketed prescription medicine for testosterone replacement (Aspen, originally Organon) and is dispensed legally with a prescription. Equivalent multi-ester products are sold as Omnadren and various 'Sustanon 350' underground-lab variants. Legitimate use cases include male hypogonadism and masculinizing hormone therapy for transgender men. Possession or distribution without a valid prescription is an offense in most jurisdictions; the controlled-substance classification varies by country.
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