Anavar's half-life is about 10 hours (Oxandrin FDA label: mean elimination half-life 10.4 h in younger volunteers, 13.3 h in elderly subjects).
Half-life estimate, not bloodwork or dosing advice. Disclaimer.
By Austin Witherow and Mason Calvert · Last updated · Sources
| Measure | 50 mg once a day, after the last dose |
|---|---|
| Highest amount | 60.7 mg, 1 hour after the last dose |
| 50% of that left | 12 hours after the last dose |
| 10% of that left | 1.5 days after the last dose |
| 3% of that left | 2.3 days after the last dose |
| Levels off | Around day 3 |
On the example input, 50 mg once a day, the curve levels off around day 3; after the last dose it takes 1.5 days to fall to 10% of its final 60.7 mg peak and 2.3 days to fall to 3%.
A single 50 mg dose fades on the same timeline from a lower peak of 50 mg of oxandrolone, because every dose in the model decays at the same 10-hour half-life.
This is the modeled amount of the drug itself. Drug tests look for metabolites and use different, often longer, windows. Pedplot does not estimate detection times.
| Frequency | Each dose | High point | Low point | Swing |
|---|---|---|---|---|
| Every other day (open in plotter) | 100 mg | 103 mg | 3.46 mg | 97% |
| Daily (open in plotter) | 50 mg | 60.7 mg | 11.5 mg | 81% |
Each schedule name opens that curve in the plotter.
The example input adds up to 350 mg a week. Given every other day as one 100 mg dose, the modeled amount swings 97% between its high and low point; split into 50 mg once a day, the swing is 81%.
The chart shows days 28 to 42 of a 6-week run, after both schedules have levelled off.
The plotter's shortest interval is one day, so it cannot show the same 50 mg split into two doses a day.
The Oxandrin FDA label reports a mean elimination half-life of 10.4 hours in younger volunteers and 13.3 hours in elderly subjects, from two single-dose studies. It found no significant difference in time to peak between the two groups, but gives no time-to-peak value.
Linakis et al. 2020 measured an average of 6.7 hours in a small adult study of an oxandrolone liquid in medium-chain triglyceride oil given by the buccal route, with half-lives similar to the tablet's. The spread between people was wide, a coefficient of variation of 70%.
The same study put the tablet's time to peak at 1.6 hours, with most peaks about 1 hour after the dose, which is the figure the plot uses.
The plot's half-life of about 10 hours sits just under the label's figure for younger adults. Because an FDA label gives it for this exact product and route, the data quality is high.
| Compound | Half-life | Time to peak | Parent share | Levels off | To 10% after last dose |
|---|---|---|---|---|---|
| Anavar | 10 hours | 1 hour | 100% (no ester) | Day 3 | 1.5 days |
| Winny | 10 hours | 1 hour | 100% (no ester) | Day 3 | 1.5 days |
| Dianabol | 5 hours | 1 hour | 100% (no ester) | Day 2 | 18 hours |
| Test E | 4.5 days | 2 days | 72% | Day 24.5 | 17 days |
Each row uses that compound's own example input. Of these, Dianabol falls to 10% of its final peak soonest after the last dose (18 hours), and Test E takes longest (17 days).
The plot uses 10 hours, the figure from the Oxandrin FDA label. The Oxandrin label reports 10.4 hours in younger volunteers and 13.3 hours in elderly subjects. At that rate the modeled amount falls to half its peak 12 hours after the last dose, as the washout table shows.
In the model each dose climbs in a straight line to its peak 1 hour later, the value in the key numbers table. Linakis et al. 2020 measured a tablet time to peak of 1.6 hours in adults, with most peaks about 1 hour after the dose; the Oxandrin label gives no time to peak.
After the last dose in the example input (50 mg once a day), the modeled amount falls to 10% of its final 60.7 mg peak in 1.5 days and to 3% in 2.3 days, as the washout table shows. This is drug remaining in the model, not a drug-test window.
The Oxandrin label's two figures come from two groups of different ages, and the 6.7 hours in Linakis et al. 2020 comes from a small study of an oil-based liquid held in the mouth, with a wide spread between people. The plot uses 10 hours, and the notes on each source explain why the figures differ.
Data quality: High. How the model works.