Follow the instructions and medical advice of your provider when taking Cialis. Hims offers access to once-a-day Cialis.​ Buy Cialis online is taken once a day at the same time, no matter how often you have sex. It only takes 4-5 days for daily to become fully effective and you can expect peak concentration in as little as 30 minutes. Cialis can be taken with or without food, so taking it around the same mealtime is an option.