An erectile-dysfunction medicine (prescription). Included for one specific, lethal reason: combining it with nitrates or poppers causes a sudden, dangerous drop in blood pressure.

Dose and effect data: PsychonautWiki (CC BY-SA 4.0) and TripSit (PolyForm Noncommercial 1.0.0). Not covered by PsychonautWiki — data comes from TripSit. Prescription or supplement entry — included for interaction checking, not as recreational dose guidance. Less-used substance: fewer independent sources, so treat these numbers with extra caution.

Before you dose

Dose

Published population range

No weight-based model for this substance — published ranges only.

Expected effects

• Improved erectile function (prescription medicine)

Possible side effects

• Headache and flushing
• Dizziness from lowered blood pressure
• Visual disturbances
• Never combine with nitrates, poppers or blood-pressure medication - dangerous hypotension
• Priapism (rare emergency)

Harm reduction

• Dosina shows prescription medicines so their interactions are visible - not so you can use them recreationally.
• Never stop a prescribed medicine abruptly to take something else. Antidepressant discontinuation syndrome is real and can be severe; talk to your prescriber first.
• SSRIs, SNRIs, MAOIs, lithium and tricyclics all interact with recreational drugs in ways that range from 'wastes your money' to 'kills you'.
• Serotonin syndrome is the emergency to watch for: agitation, confusion, tremor, sweating, muscle rigidity, fever and a fast heartbeat after combining serotonergic drugs. It can become fatal within hours.
• Keep any prescription medicine in its original packaging and never share it.

Sources

• TripSit wiki — Sildenafil (PolyForm Noncommercial)
https://wiki.tripsit.me