No human study we could check reports NPP's half-life; the plot uses an estimate of about 1.5 days.
Half-life estimate, not bloodwork or dosing advice. Disclaimer.
By Austin Witherow and Mason Calvert · Last updated · Sources
| Measure | 100 mg every other day, after the last dose |
|---|---|
| Highest amount | 111 mg, 1 day after the last dose |
| 50% of that left | 2.5 days after the last dose |
| 10% of that left | 6 days after the last dose |
| 3% of that left | 8.8 days after the last dose |
| Levels off | Around day 8 |
On the example input, 100 mg every other day, the curve levels off around day 8; after the last dose it takes 6 days to fall to 10% of its final 111 mg peak and 8.8 days to fall to 3%.
A single 100 mg injection fades on the same timeline from a lower peak of 67 mg of nandrolone, because every dose in the model decays at the same 1.5-day 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 |
|---|---|---|---|---|
| Twice a week (open in plotter) | 175 mg | 146 mg | 46.1 mg | 69% |
| Every 3 days (open in plotter) | 150 mg | 134 mg | 53.2 mg | 60% |
| Every other day (open in plotter) | 100 mg | 111 mg | 70 mg | 37% |
Each schedule name opens that curve in the plotter.
The example input adds up to 350 mg a week. Given twice a week as one 175 mg injection, the modeled amount swings 69% between its high and low point; split into 100 mg every other day, the swing is 37%.
The chart shows days 70 to 84 of a 12-week run, after all three schedules have levelled off.
Once a day is left out: each injection takes 1 day to reach its peak in the model, so at that gap every injection would land while the one before was still rising, and the curve would look artificially flat.
No human study we could check reports NPP's half-life. The plot uses a community estimate of about 1.5 days.
No FDA label or SmPC covers nandrolone phenylpropionate. The one human study found, Minto et al. 1997, gave 100 mg of the phenylpropionate or the decanoate as a single injection and sampled blood for 32 days.
The full text of that study could not be checked, and no other human pharmacokinetic study of the ester was found. Its abstract reports higher and earlier peaks with the phenylpropionate, but gives no half-life or time to peak.
Half-life figures attributed to Minto 1997 elsewhere could not be verified against the paper, so this page does not use them.
The plot's 1.5 days and its 1-day time to peak are community estimates and are marked as estimates. The ester weight, computed from PubChem, is the one NPP number here with a firm basis.
| Compound | Half-life | Time to peak | Parent share | Levels off | To 10% after last dose |
|---|---|---|---|---|---|
| NPP | 1.5 days | 1 day | 67% | Day 8 | 6 days |
| Deca | 7.5 days | 2 days | 64% | Day 42 | 27 days |
| Test P | 19 hours | 1 day | 84% | Day 5 | 3.8 days |
| Tren A | 1 day | 12 hours | 87% | Day 6 | 4 days |
Each row uses that compound's own example input. Of these, Test P falls to 10% of its final peak soonest after the last dose (3.8 days), and Deca takes longest (27 days).
The plot uses a community estimate of 1.5 days, marked as an estimate. The one human study found, Minto et al. 1997, could be read only as an abstract, and the abstract gives no half-life. At that rate the modeled amount falls to half its peak 2.5 days after the last injection, as the washout table shows.
NPP has a half-life of 1.5 days against 7.5 days for Deca, so Deca is the longer-acting of the two in the model. Per mg, NPP is 67% nandrolone and Deca 64% nandrolone. On their own example inputs, NPP falls to 10% of its final peak 6 days after the last dose and Deca 27 days, as the comparison table shows. The Minto et al. 1997 abstract confirms the direction: after the same 100 mg dose, the phenylpropionate gave higher and earlier peaks than the decanoate.
With the same 350 mg a week, the modeled swing between the high and low point is 69% at 175 mg twice a week, 60% at 150 mg every 3 days and 37% at 100 mg every other day, as the frequency comparison shows. Once a day is not compared, because each injection takes 1 day to peak in the model.
After the last injection in the example input (100 mg every other day), the modeled amount falls to 10% of its final 111 mg peak in 6 days and to 3% in 8.8 days, as the washout table shows. This is drug remaining in the model, not a drug-test window.
Data quality: Low. How the model works.