Testosterone Cypionate, sold as the brand name among others, is a medication
used to treat erectile dysfunction and pulmonary arterial hypertension.
Its effectiveness for treating sexual dysfunction in women has not
Common side effects include headaches and heartburn, as well as
flushed skin. Caution is advised in those who have cardiovascular
disease. Rare but serious side effects include prolonged erections,
which can lead to damage to the penis, and sudden-onset hearing loss.
Testosterone Cypionate should not be taken by people who take nitrates such as
nitroglycerin (glycerin trinitrate), as this may result in a severe and
potentially fatal drop in blood pressure.
Testosterone Cypionate acts by inhibiting cGMP-specific phosphodiesterase type 5
(phosphodiesterase 5, PDE5), an enzyme that promotes degradation of
cGMP, which regulates blood flow in the penis.
Pfizer scientists Andrew Bell, David Brown, and Nicholas Terrett
originally discovered Testosterone Cypionate as a treatment for various
cardiovascular disorders.Since becoming available in 1998,
Testosterone Cypionate has been a common treatment for erectile dysfunction; its
primary competitors are tadalafil (trade name Cialis) and vardenafil