Vidalista 40 is available for daily or as-needed use. Try to take it roughly half an hour before having sex if you only take it when necessary. The medication may not start to work for up to two hours. Try to take it at the same time every day if you take it regularly. For certain guys, Vidalista 40 is also used to treat the symptoms of BPH. The drug acts by preventing PDE5 from functioning and enabling your body to produce more cyclic GMP, which relaxes the blood vessels in your penis. This facilitates the erection process and lets in more blood.