This type of medicine should be used only by guys and that too only after the consultation of doctor. These will not support the system of women or guys under the age of 18. At no situation the user should increase the dosage as per their interest with out any consultation this may lead to very severe effect which is not realized by many. It is found that they are little slow in their performance if used after a very high fat dinner. So it is better to limit the both content and quantity of your meals. Even alcohol is found to limit the action of the chemical substance so it is better to avoid the habit of drinking before taking these tablets for the best output. Both generic viagra and generic cialis function is similar only they differ with the base chemical substance which supports the function. Even the dosage level and the ability of with held the power to some extent differs. They are cheap and can be brought even through viagra online. They are available through out the world but this medicine level usage is found to be at great level in America which indicates the reliability of the products.