HALF-LIFE OF ANABOLIC STEROIDS
A practical reference for the approximate half-life of commonly encountered anabolic steroids and related compounds.
What does half-life mean?
The half-life of a substance is the approximate time required for its concentration in the body to decrease by half. It is one of the most useful pharmacokinetic measurements for understanding how long a compound remains active in the body.
Half-life does not mean that a substance is completely gone after one or two half-lives. In general, several half-lives are required for the concentration to fall substantially.
The values below are approximate. Actual pharmacokinetics can vary depending on the compound, formulation, ester, route of administration, individual metabolism, and other factors.
Important: half-life is not the same as detection time
A compound may remain detectable in the body considerably longer than its pharmacological half-life. Metabolites can also remain detectable after the parent compound has fallen to low concentrations.
Therefore, the half-life shown in these tables should not be interpreted as a reliable estimate of how long a substance can be detected in a drug test.
Oral Anabolic Steroids
| Compound | Approximate half-life |
|---|---|
| Fluoxymesterone (Halotestin) | ~9–10 hours |
| Methandienone / Methandrostenolone (Dianabol) | ~4–6 hours |
| Methyltestosterone | ~3–4 hours |
| Oxandrolone (Anavar) | ~9–10 hours |
| Oxymetholone (Anadrol) | ~8–9 hours |
| Stanozolol (Winstrol) | ~8–10 hours |
| Chlorodehydromethyltestosterone (Turinabol) | ~16 hours |
| Mesterolone (Proviron) | ~12 hours |
Injectable Anabolic Steroids
| Compound / Ester | Approximate apparent half-life |
|---|---|
| Testosterone Suspension | ~1 day or less |
| Testosterone Propionate | ~2–4 days |
| Testosterone Phenylpropionate | ~4–5 days |
| Testosterone Enanthate | ~4–5 days |
| Testosterone Cypionate | ~8 days |
| Testosterone Undecanoate | Several weeks |
| Sustanon / Omnadren | Depends on the ester mixture |
| Nandrolone Phenylpropionate | ~2–4 days |
| Nandrolone Decanoate | ~6 days for depot release* |
| Boldenone Undecylenate | ~7–14 days |
| Trenbolone Acetate | ~2–3 days |
| Drostanolone Propionate (Masteron) | ~2–3 days |
| Methenolone Enanthate (Primobolan Depot) | ~5–10 days |
| Stanozolol Injectable | ~1 day |
Why do injectable steroids have different half-lives?
Many injectable anabolic steroids are testosterone- or nandrolone-related hormones attached to an ester. The ester changes how quickly the compound is released from the injection site into the bloodstream.
In simple terms, shorter esters generally release the active hormone more quickly, while longer esters create a slower and more prolonged release.
This is why it is more useful to refer to the half-life of the complete injectable formulation rather than assigning one universal half-life to an ester by itself.
Related Hormonal and Ancillary Compounds
| Compound | Approximate half-life |
|---|---|
| Anastrozole (Arimidex) | ~50 hours |
| Letrozole (Femara) | ~2 days |
| Tamoxifen (Nolvadex) | ~5–7 days |
| Clomiphene (Clomid) | ~5 days* |
| Clenbuterol | ~1.5–2 days |
| Ephedrine | ~3–6 hours |
| Liothyronine (T3) | ~1 day |
| Aminoglutethimide (Cytadren) | ~6 hours |
A note about half-life values
Half-life figures reported online do not always agree. This is particularly common with anabolic steroids that are not widely studied in modern human pharmacokinetic trials.
For some compounds, published values are based on older studies, different formulations, animal studies, or estimates derived from the pharmacokinetics of related compounds. For that reason, values in this table are presented as approximate ranges rather than exact numbers whenever the available evidence does not justify greater precision.
The value for nandrolone decanoate is a good example: a human pharmacokinetic study found an approximately 6-day half-life for release of the ester from the intramuscular depot, while the half-life of nandrolone itself after hydrolysis was much shorter. These are different pharmacokinetic measurements and should not be treated as interchangeable.
Quick Reference
| Category | Typical pattern |
|---|---|
| Short-acting oral steroids | Usually several hours |
| Short-acting injectable esters | Usually a few days |
| Longer testosterone esters | Several days to weeks |
| Long-acting anabolic depot formulations | Several days to weeks |
| Estrogen-control medications | Approximately 2–7 days, depending on the compound |
Summary
Half-life is a useful way to understand how quickly a compound is cleared from the body, but it is only one part of pharmacokinetics. The formulation, ester, route of administration, metabolites, and individual differences can all affect how long a substance remains active or detectable.
The values on this page should therefore be considered a practical reference rather than exact predictions for an individual person.
