The official advice is that Tadalafil 20mg Generic tablets are not suitable to be split, and patients should use the minimum effective dose as a whole tablet. However, they do not have an extended or delayed release coating, so should be safe to split - and should contain an even amount of active ingredient. Cialis or tadalafil tablets are not 'scored' (an indented line in the middle of the tablet) so ensuring an even split is difficult. Purchasing a pill-splitter will help the process. Cialis manufactured by Eli Lilly in Australia, Canada, New Zealand, the United Kingdom, the United States ? and other countries.
https://www.alldaygeneric.com/product/tadalafil-20mg-cialis-20mg/