Eriacta 100 mg contains sildenafil 100 mg (the active ingredient is sildenafil, commonly referred to as sildenafil citrate). It is manufactured/marketed by Sun Pharmaceutical Industries Ltd. and is used for erectile dysfunction. 1 1mg +1 So, among the medicines you've mentioned: Eriacta 100 mg → sildenafil 100 mg Fildena 100 mg → sildenafil 100 mg Silagra 50 mg → sildenafil 50 mg Vigora 50 mg → sildenafil 50 mg Malegra 50 mg → sildenafil 50 mg Tadarise 20 mg → tadalafil 20 mg Don't combine Eriacta with the other sildenafil products or with tadalafil unless a doctor specifically advises it. Eriacta 100 mg should generally not be taken more than once in 24 hours. 1 1mg If you're asking which of these is strongest or lasts longest, I can compare all six.