Side Effects and Precautions Every Rose has its Thorn While Cialis promises a multitude of benefits, it’s essential to approach it with a discerning mind. Cialis contains 10mg or 20mg of the active ingredient tadalafil. Tadalafil is the active ingredient in a branded drug called Cialis. Most men start with and respond well to the 10 mg tadalafil dose. Does Cialis lose effectiveness over time? The most common side effects are headaches, feeling sick, indigestion and facial flushes. Why is it called generic Cialis?Note: Some pharmacies do not allow the savings card to be used for opioid drugs. How much does tadalafil or cialis cost near you? Find the best tadalafil or cialis prices near . Save £ Was £ 4 UNI | £ per 1UNI. Save 10 percent on Cialis Together 10mg Tablets Tadalafil 4 Tablets. Free next day delivery on selected medicines when you use code HEALTHFNDD, order by 8pm – online only. Helps you get and maintain an erection when you need it. Effective up to 36 hours. Cialis is an effective treatment for mild to severe ED. On the standard starting dose of 10mg of the active ingredient in Cialis, tadalafil, 71% of men reported an erection suitable for sex. On a higher 20mg dose of tadalafil, 73% of men reported improved erections. On Cialis Daily, 84% of men reported improved erections and 72% preferred.