Explore Tadalafil dosage trends, reconstitution volumes, and vial size patterns from anonymized WPA peptide calculator data.
Tadalafil is a long-acting PDE5 inhibitor and an FDA-approved drug (Cialis/Adcirca) sometimes sold as research-grade powder. It is a small molecule, not a peptide, and is taken orally, so the certificate of analysis (COA) is about chemical purity and accurate dose per unit.
Tadalafil selectively inhibits cGMP-specific phosphodiesterase type 5 (PDE5), the enzyme that degrades cyclic guanosine monophosphate (cGMP) in vascular smooth muscle. Sexual stimulation triggers nitric oxide release in the corpus cavernosum, which activates guanylate cyclase, which raises cGMP, which produces smooth-muscle relaxation and corporal blood inflow. PDE5 inhibition amplifies and sustains this cGMP signal, supporting erection. The same pharmacology in pulmonary arterial smooth muscle is the mechanism for the PAH indication; in prostate and bladder smooth muscle, PDE5 inhibition relaxes lower-urinary-tract tissue and improves BPH-related lower urinary tract symptoms. Tadalafil's ~17.5-hour half-life — substantially longer than sildenafil or vardenafil — supports both the on-demand 24–36-hour effective window and the once-daily dosing schedule.[3]
The original PDE5-inhibitor erectile dysfunction trials (Brock et al., J Urol 2002; Porst et al., Eur Urol 2006) established efficacy and the long effective window that distinguishes tadalafil from sildenafil.[2][4] The PHIRST trial (Galiè et al., Circulation 2009) established efficacy in PAH and supported the Adcirca approval.[5] BPH efficacy was established in a series of trials (Porst et al., Eur Urol 2011) supporting the 2011 label addition for BPH-related lower urinary tract symptoms, with or without coexisting erectile dysfunction.[6] An active research area is daily low-dose tadalafil as a vascular-endothelial-function intervention, with some evidence in cardiovascular disease and Duchenne muscular dystrophy (the latter a failed Phase 3 program despite an exciting Phase 2 signal).[7]
FDA-approved as Cialis for erectile dysfunction (2003, on-demand and 2008 daily-use indications) and BPH (2011); as Adcirca for pulmonary arterial hypertension (2009); generic and authorised-generic tadalafil widely available since 2018. Research-grade material elsewhere.
Tadalafil has a reported half-life of ~17.5 hours. The pharmacokinetic reference models an interval of once daily or as needed; this is not a measured community cadence or a dosing recommendation. The long half-life is why a single dose can work for over a day, and why low daily dosing builds to a steady level over about 5 days. Effects long outlast other ED medications. Pharmacokinetic source: FDA label (Cialis). It is catalogued under Other Peptides on WPA.
5 Tadalafil reconstitution calculations have been logged by the WPA community.
This is the lifetime header population. Each chart and its associated analysis below use their own selected period and denominator; frequency responses are a separate cohort.
These figures come from anonymized WPA peptide calculator sessions, not verified administrations or unique people. Separate modal inputs do not establish a joint protocol. They are community input statistics — not dosing recommendations, and not medical advice.
These figures come from anonymized WPA peptide calculator sessions.
All figures shown are aggregated from anonymized calculator inputs and are provided strictly for independent laboratory research and educational purposes. They are community usage statistics — not dosing recommendations, and not medical advice.