Samuel Ward always recommends the Viagra 50mg to first time users with erectile dysfunction. The lowest dose is considered safe by the doctor for younger and mature users. 100mg boosts the blood flow to the sexual organ of male to give an erection under sexual stimulation. Doctor recommends some tips for safe usages of the dose. The first is that user should not mix any other drug or medicine with the Viagra. And never use the two Viagra within 24 hours. The doctor also conducts the preliminary medical examination to make sure that user can safely use the dose.