An erection is a physiological response in which the penis becomes rigid and enlarged due to increased blood flow. This response is triggered by sexual stimulation, which induces the release of a vasodilator molecule called nitric oxide. Nitric oxide activates an enzyme that catalyzes the conversion of GTP to cGMP, a molecule that leads to smooth muscle relaxation and blood vessel dilation, increasing blood flow into the penis and resulting in an erection.
Phosphodiesterases are the group of enzymes in the body responsible for breaking down cGMP. Two of the medications in Rugiet Ready, sildenafil and tadalafil, are phosphodiesterase type 5 (PDE5) inhibitors. Inhibiting PDE5 increases the amount of available cGMP, which in turn increases smooth muscle relaxation and blood vessel dilation, increasing overall blood flow into the penis and resulting in an erection.
Apomorphine, the third ingredient in Rugiet Ready, is a dopamine promoter that acts on dopamine receptors in the brain. It primes the parts of the brain associated with sexual arousal, strengthening the signal that links sexual stimulation and the erection cascade.