---
title: "Terazosin (and related repurposed blood-pressure drugs): Parkinson's Drug Pipeline"
description: Repurposed blood-pressure medicines being explored as possible disease-modifiers. The evidence is mostly from health-record databases and small studies, intriguing but far from proven.
canonical_url: "https://parkinsonspathways.com/pipeline/terazosin-repurposed"
development_stage: "Phase 2: mid-stage testing"
last_updated: 2026-06-01
source: "Parkinson's Pathways"
---
# Terazosin (and related repurposed blood-pressure drugs)

**Stage:** Phase 2 / early clinical  ·  **Type:** Disease-modifying

**Developer:** Academic / investigator-led (repurposed drugs)

**How it works:** Terazosin is an old prostate/blood-pressure pill that also switches on an energy-making enzyme (PGK1) in cells; researchers are testing whether boosting brain-cell energy could be protective. Telmisartan, another blood-pressure drug, is being explored separately on an anti-inflammatory rationale.

**Target:** PGK1 / cellular energy metabolism

**Who it's for:** People with Parkinson's; some signals come from people taking these drugs for other reasons.

**Last reviewed:** 2026-06-01


## What it is

Terazosin has been used for decades for an enlarged prostate and high blood pressure. It was found to also boost an enzyme (PGK1) that helps cells make energy, and laboratory and database studies suggested people taking it might have a lower risk or slower progression of Parkinson's. Telmisartan, another blood-pressure drug, is being studied separately on an anti-inflammatory rationale.

## Where it stands

These are early repurposing ideas. Some signals come from health-record analyses (which can be biased) plus small clinical studies; properly controlled trials in Parkinson's are limited and ongoing.

## What the data shows so far

The strongest terazosin signals so far come from observational database studies and small mechanistic studies, not from large randomized trials proving it slows Parkinson's. Database comparisons are prone to bias, so they generate hypotheses rather than answers. Telmisartan evidence is earlier still.

## What families should know

These are not approved Parkinson's treatments, and you should not start a blood-pressure drug to treat Parkinson's outside a trial. They lower blood pressure and can cause dizziness or fainting. They are promising research leads, not proven therapies.

## Caveats

No large randomized trial has shown terazosin or telmisartan slows Parkinson's. Much of the support is observational and can be confounded. Both lower blood pressure, which carries real risks in older people. Do not self-medicate.

## Timeline

_Most recent first._

- **2022-2024**, Small clinical and repurposing studies explore terazosin and telmisartan in Parkinson's.
- **2019-2021**, Database and laboratory studies suggest terazosin may be protective in Parkinson's.

## Sources

- [Search Parkinson's repurposing trials on ClinicalTrials.gov](https://clinicaltrials.gov/search?cond=Parkinson%20Disease&intr=terazosin)

_Last reviewed: 2026-06-01._

## More

- [Back to the Parkinson's drug pipeline](https://parkinsonspathways.com/pipeline)
- [Browse all recruiting trials](https://parkinsonspathways.com/trials)