Tadalafil, known as Generic Cialis, is now licensed in the UK as a more affordable generic form for the treatment of erectile dysfunction. You can buy Tadalafil (Generic Cialis) as 10mg and 20mg strength tablets to be used on a when required basis. Tadalafil tablets are proven to work within 30 minutes to produce the desired effect and are considered to have a longer lasting effect in comparison to other ED medication.