Cialis, like Viagra, is a PDE5 inhibitor that increases blood flow to the penis by relaxing the smooth muscle in blood vessel walls. Its primary use is for treating erectile dysfunction (ED), but it is also approved for the treatment of benign prostatic hyperplasia (BPH), a condition characterized by enlarged prostate. The major benefit of Cialis is its long half-life, which can last up to 36 hours, earning it the nickname �the weekend pill.� This extended duration allows for greater spontaneity in sexual activity compared to Viagra, which requires more precise timing. Additionally, Cialis can be taken on a daily basis at lower doses for men who want a constant readiness for sexual activity and can also improve urinary symptoms associated with BPH.