Daily Dosage of Sustanon at 500 mg Weekly
When administering Sustanon at a total weekly dose of 500 mg, the daily dosage is approximately 71.4 mg per day (500 mg ÷ 7 days).
Understanding the Dosing Context
This 500 mg weekly dose represents a supraphysiologic dose that substantially exceeds guideline-recommended testosterone replacement therapy (TRT) parameters. Standard TRT protocols recommend:
- Injectable testosterone enanthate or cypionate: 50-100 mg weekly or 100-200 mg every 2 weeks via intramuscular injection 1
- Target testosterone levels: Mid-normal range of 450-600 ng/dL 1
The 500 mg weekly dose is 5-10 times higher than standard therapeutic dosing and is typically associated with performance enhancement rather than medical testosterone replacement 1.
Pharmacokinetic Considerations
Sustanon is a blend of four testosterone esters with different half-lives: testosterone propionate, testosterone phenylpropionate, testosterone isocaproate, and testosterone decanoate 2. This combination creates:
- Peak serum levels: Occur 2-7 days after injection 3
- Progressive decline: Testosterone levels fall toward baseline by days 10-14 for standard esters 3
- Fluctuating concentrations: Patients spend significant time in both supraphysiologic and subtherapeutic ranges between injections 3
At 500 mg weekly, testosterone levels will remain persistently supraphysiologic throughout the dosing interval, never reaching the trough levels seen with therapeutic dosing 3.
Critical Safety Concerns at This Dose
Erythrocytosis Risk
Injectable testosterone at therapeutic doses causes erythrocytosis in 43.8% of patients, compared to only 15.4% with transdermal preparations 1. At 500 mg weekly—a supraphysiologic dose—this risk is substantially amplified:
- Dose-dependent hematocrit elevation occurs with all injectable formulations 1
- Hemoconcentration from elevated hematocrit can aggravate vascular disease in coronary, cerebrovascular, or peripheral circulation 1
- Mandatory hematocrit/hemoglobin monitoring is essential at this dose 1
Hepatotoxicity Profile
Injectable testosterone esters do NOT produce clinically significant liver injury in men with normal baseline liver function because they bypass first-pass hepatic metabolism and are not 17-α-alkylated 1. However:
- Research using Sustanon 10 mg/kg weekly in rats (roughly equivalent to 70 mg weekly in a 70 kg human) showed upregulation of hepatic antioxidant enzymes without severe liver damage 4
- At 500 mg weekly (7× the research dose), liver function monitoring is prudent despite the low intrinsic hepatotoxic risk 1
Reproductive System Effects
Research demonstrates that Sustanon at doses of 10-30 mg/kg weekly in rats causes:
- Significant reductions in testicular weight, sperm count, LH, and FSH concentrations 5
- Suppression of spermatogenesis and increased testicular cell death 5
- Decreased BCL2 gene expression, indicating reduced cell survival 5
At 500 mg weekly in humans, complete suppression of endogenous testosterone production and spermatogenesis is virtually certain 5.
Monitoring Requirements at Supraphysiologic Doses
If this dose is being used (which exceeds all guideline recommendations), the following monitoring is mandatory:
- Hematocrit/hemoglobin: At every visit, with dose reduction or therapy withholding if elevation occurs 1
- Testosterone levels: Measured midway between injections at 2-3 months, though levels will be supraphysiologic 1, 3
- Liver enzymes: Not routinely required for injectable testosterone, but reasonable at this dose 1
- Lipid profile: Periodically, as supraphysiologic testosterone affects lipid metabolism 1
- PSA and digital rectal examination: For men >40 years 1
Common Pitfalls to Avoid
Do not assume this dose is medically appropriate simply because it can be calculated mathematically—500 mg weekly is not supported by any clinical guideline for testosterone replacement therapy 1. This represents performance-enhancing use rather than medical treatment.
Do not measure testosterone levels shortly after injection—patients will appear to have extremely elevated testosterone when measured at peak (2-7 days post-injection), but this does not reflect the average exposure 3.
Do not ignore cardiovascular risk—injectable testosterone at therapeutic doses may carry greater cardiovascular risk than transdermal preparations due to fluctuating levels, and this risk is amplified at supraphysiologic doses 1, 3.