Hi Thaddeus,

I would recommend Dr. Susan Bennoff's research papers for information
on how nifedipine works as a male contraceptive.

Hershlag, et al. (1995) Human Reproduction 10: 599
Goodwin, et al. (1997) Molecular Human Reproduction 3: 255
Benoff (1998) Frontiers in Bioscience 3: 1220

We have a copy of the Frontiers in Bioscience paper on our website:
www.malecontraceptives.org/methods/articles/benoff_bioscience.htm

Here are 3 reasons not to experiment with this on your own:

1) The safety of nifedipine in men with hypertension is well
established. However, its safety has not been widely established
among people with blood pressures in the normal range. Nifedipine
(and its calcium channel blocker cousins) are sometimes prescribed to
migraine sufferers with normal blood pressure. In these patients
doctors report side effects including dizziness, headache,
depression, vasomotor changes, tremor, orthostatic hypotension
(extremely low blood pressure when standing), and bradycardia
(abnormally slow or unsteady heart rhythm). I don't have information
on what percentage of migraine patients experience these side effects.

2) To date no one has tested the contraceptive efficacy of
nifedipine. Aside from the anecdotal evidence, we do not have any
information about the consistency or degree of its efficacy as a
contraceptive in men.

3) Most importantly:
You cannot verify the contraceptive efficacy of nifedipine through a
sperm count or motility test. A man taking nifedipine has completely
normal sperm counts, all the sperm look normal under a microscope,
and they are all motile. The only way to test its contraceptive
efficacy is to have unprotected sex and see what happens.


- Kirsten