The FDA conducted analytical tests of X-ROCK for men, which showed that products contained sildenafil and hydroxythiohomosildenafil.
Hydroxythiohomosildenafil is an analogue sildenafil and is expected to possess a similar pharmacological and adverse event profile.
The sildenafil and hydroxythiohomosildenafil may interact with nitrates found in some prescription drugs (such as nitroglycerin) and lower blood pressure to dangerous levels.
Additionally, hydroxythiohomosildenafil, like sildenafil, may cause side effects, such as headaches and flushing.