Tadalafil
tah-DAL-ah-fil
A long-acting ED medication that can last up to 36 hours — also used daily at low doses for ongoing support.
Also known as: Cialis
FDA approved for: Erectile dysfunction · Benign prostatic hyperplasia (BPH) · Pulmonary arterial hypertension
Last reviewed: April 2026
What It Does
Like sildenafil, tadalafil blocks the PDE5 enzyme to improve blood flow during arousal. The key difference is duration — tadalafil lasts up to 36 hours, earning it the nickname 'the weekend pill.' At daily low doses (2.5–5mg), it provides around-the-clock readiness.
Why People Take It
How It's Administered
Oral
As-needed: take 30 minutes to 2 hours before activity. Daily: take at same time each day.
Frequency
As needed or daily
Pain Level
○○○ None
Self-Administered
Yes — at home
Typical Range
2.5mg daily or 10mg – 20mg as needed
What To Expect
30 min – 2 hours
Effects begin (faster on empty stomach).
2–12 hours
Peak effectiveness.
Up to 36 hours
Effects can persist — the 'weekend' duration.
Side Effects
Overall: Mild
Common (1–10%)
Headache
Most common side effect, usually mild.
Back pain
Unique to tadalafil, resolves in 24–48 hours.
Muscle aches
Typically in legs, temporary.
Indigestion
Acid reflux or upset stomach.
Who Should NOT Take This
• Currently taking nitrates
• Severe liver disease
• Recent stroke or heart attack
• Hypotension
Drug Interactions
• Nitrates — NEVER combine, life-threatening hypotension
• Alpha-blockers — start with lower tadalafil dose
• Ritonavir — increases tadalafil levels significantly
Pregnancy: Not indicated for women. If prescribed off-label, not for use in pregnancy.
Clinical Details
Compare With Similar Peptides
Longer-acting than sildenafil. Daily dosing provides continuous support without timing pressures.
Sildenafil
The original erectile dysfunction medication — relaxes blood vessels to improve blood flow when aroused.
PT-141 (Bremelanotide)
A peptide that increases sexual desire by acting on the brain — works differently from ED medications that only improve blood flow.
Frequently Asked Questions
This peptide is available through our protocols.
FDA-approved for at least one indication. Your provider will determine if this is appropriate for you.