7 Day Nolva half-life and effect on subsequent PH cycle

[mark]

Data indicates that Nolva has a 7 day half-life.

It would appear that "2 on 2 off 2 on" cycles would have to take into consideration that the later 2 week on portion of the cycle would be effected by the residual Nolva still in the system, assuming PCT was utilized during the 2 off.

With a Nolva PCT of 20mg/day during the "2 off", your system would have the equivalent of 10 mg/day one week into the second "2 on", and 5 mg/day at the end of the two weeks.

Doesn't this have a significant effect? Anyone take this into consideration?

M

 

[Longdog]

Nolva in your system will reduce estrogen, hence estrogen related sides. Having less water retention & estrogen in your system can slightly hinder gains. I have run nolva on-cycle, & honestly didn't notice any less gains.

 

[tatortodd]

Data indicates that Nolva has a 7 day half-life.

Please post your reference for this data. That is much longer than I remember reading about.

~Todd

 

[Dwight Schrute]

Nolva in your system will reduce estrogen, hence estrogen related sides. Having less water retention & estrogen in your system can slightly hinder gains. I have run nolva on-cycle, & honestly didn't notice any less gains.

Nolva does not reduce circulating estrogen to the point it reduces side effects. Its blocks the receptor that causes side effects. In other words, Nolva shouldn't hinder gains to any significant degree at all.

It can also cause more water retention because its an AVP agonist.

 

[mark]

Please post your reference for this data. That is much longer than I remember reading about.

~Todd

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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.

In a 3-month crossover steady-state bioavailability study with tamoxifen citrate 10 mg twice a day versus tamoxifen citrate 20 mg given once daily, tamoxifen citrate 20 mg taken once daily has comparable bioavailability to tamoxifen citrate 10 mg taken twice a day.



Also note the last paragraph - A good referenced answer to the once a day vs. twice a day question.

M