Tadalafil is a PDE5 inhibitor used for erectile dysfunction, benign prostatic hyperplasia (BPH), and pulmonary arterial hypertension. It's distinguished from other PDE5 inhibitors by its exceptionally long half-life of 17.5 hours, producing clinical effects for up to 36 hours — earning it the nickname "the weekend pill."

Now off-patent, compounded tadalafil delivers identical therapeutic effects to brand Cialis at 5–15% of the cost. Daily low-dose tadalafil (2.5–5mg) has become a popular protocol for men seeking spontaneity without timing a dose, and also provides consistent BPH symptom relief.

Compounding allows custom doses, combination formulas with oxytocin or sildenafil, and sublingual troche delivery for faster onset than standard oral tablets.

PDE5 Inhibition
Like sildenafil, tadalafil selectively inhibits PDE5, preventing cGMP breakdown in vascular smooth muscle. The resulting vasodilation facilitates erection in response to sexual stimulation and reduces pulmonary vascular resistance.

Long Half-Life Advantage
Tadalafil's 17.5-hour half-life (vs. 4 hours for sildenafil) means therapeutic plasma levels persist for 36 hours, removing the need to time dosing around sexual activity.

BPH Mechanism
PDE5 is expressed in prostate and bladder neck smooth muscle. Tadalafil relaxes these tissues, improving urinary flow and reducing BPH symptoms independently of its erectile effects.

As-needed ED: 10mg or 20mg taken 30–60 minutes before activity; max once daily

Daily low-dose ED/BPH: 2.5mg or 5mg once daily, same time each day

Pulmonary Hypertension: 40mg once daily

Starting dose for ED is typically 10mg as-needed. Daily 5mg is preferred for BPH or when spontaneity is desired.

For daily dosing, allow 7 days at each dose level before assessing efficacy. Men switching from as-needed to daily dosing should start at 2.5mg and increase to 5mg if needed after 2 weeks. Daily dosing produces steady-state plasma levels within 5 days.