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Nolvadex Half-life
I was just doing some research for my PCT and found this if it helps anyone, especially athletes worried about detection times.
Following a single oral dose of 20 mg tamoxifen, an average peak plasma concentration of 40 ng/ml (range 35 to 45 ng/ml) occurred approximately 5 hours after dosing. The decline in plasma concentrations of tamoxifen is biphasic with a terminal elimination half-life about 5 to 7 days. The average peak plasma concentration for N-desmethyl tamoxifen is 15 ng/ml (range 10 to 20 ng/ml).
Chronic administration of 10 mg tamoxifen given twice daily for three months to patients results in average steady-state plasma concentrations of 120 ng/ml (range 67 to 183 ng/ml) for tamoxifen and 336 ng/ml (range 148 to 654 ng/ml) for N-desmethyl tamoxifen. The average steady-state plasma concentrations of tamoxifen and N-desmethyl tamoxifen after administration of 20 mg tamoxifen once daily for 3 months are 122 ng/ml (range 71 to 183 ng/ml) and 353 ng/ml (range 152 to 706 ng/ml), respectively.
After initiation of therapy, steady state concentrations for tamoxifen are achieved in about 4 weeks and steady state concentrations for N-desmethyl tamoxifen are achieved in about 8 weeks, suggesting a half-life of approximately 14 days for this metabolite.
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