NHS Nebido Protocol

33.9 day terminal from Behre 1999; 7 day Tmax from current Nebido label is total testosterone. Combining these yields only a relative illustrative shape.

One 1 mg input peaks at 1 relative unit after a single dose. Other amounts scale proportionally; overlapping doses add when accumulation is on. Different compounds use separate relative scales.

Timing half-life used

813.6 hours

Absorption half-life assumed

35.5809 hours

Reference amount for the relative scale

1 mg

• The faster rate is inferred to match the 168 h source-scoped peak time; absorption half-life 35.580899063328104 h is a mathematical shape parameter, not separately measured.
• A single 1-unit input has a peak of 1 relative unit; scaling and repeated-dose addition are mathematical assumptions. This normalization is independent of the example dose.
• The 14-person 1999 formulation and current Nebido label describe different kinetic summaries; 33.9 day terminal and 90 day release half-life are not interchangeable.
• No source-matched baseline/suppression model was established here. Use relative output while retaining a stated castor-oil timing scenario.
• Stored 0.65 resembles an ester mass fraction, not a demonstrated systemically available fraction.

• Behre 1999 phaseI testosterone undecanoate

  1000 mg castor-oil IM group had 33.9±4.9 day terminal half-life; tea-seed group 20.9±6.0 days. No MCT group.

• Nebido 1000 mg/4 mL SmPC §§2, 5.2

  1000 mg ester corresponds to 631.5 mg testosterone; first-injection total serum testosterone peaks at 38 nmol/L after 7 days; reported release half-life 90±40 days.

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