Viagra, or sildenafil, primarily targets an enzyme called phosphodiesterase-5 (PDE5). This enzyme breaks down a crucial molecule called cyclic guanosine monophosphate (cGMP).
CGMP’s Role in Erection
CGMP plays a vital role in achieving an erection. When sexually stimulated, nitric oxide is released, increasing cGMP levels. This increased cGMP relaxes the smooth muscles in the penis, allowing blood to flow in and creating an erection. PDE5’s job is to reduce cGMP levels, ending the erection.
Viagra’s Mechanism of Action
Viagra inhibits PDE5. By blocking PDE5, Viagra prevents the breakdown of cGMP. This leads to higher cGMP levels for a longer duration, promoting and sustaining penile blood flow necessary for an erection. It’s important to understand Viagra only works in the presence of sexual stimulation; it doesn’t spontaneously cause erections.
Specific Effects
The drug’s effects are localized primarily to the penis’s vascular system. It doesn’t directly stimulate nerve signals or increase libido. Its mechanism focuses solely on facilitating the physiological processes underlying erection.
Further Considerations
The effectiveness of Viagra can vary depending on individual factors and underlying health conditions. Always consult a doctor before using Viagra or any similar medication.