NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated July 13, 2026

Chlorthalidone

Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026

Chlorthalidone is a thiazide-like diuretic with a longer half-life and stronger evidence base than hydrochlorothiazide. It was the diuretic used in the landmark ALLHAT and SHEP trials. Major guidelines increasingly favor chlorthalidone over HCTZ for hypertension due to superior 24-hour blood pressure control and proven cardiovascular event reduction.

Evidence tier
Strong
Indexed sources
10 2021–2025
Interactions
0
Depletes
5 nutrients
Read the sources → Compare profiles
Publication status

Exploratory record, not a reviewed medical publication.

See the editorial and medical-review policies for the publication gate.

This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.

In short

What the research says.

A quick, data-only summary. The full evidence, dosing, and sources are below.

Chlorthalidone is a thiazide-like diuretic with a longer half-life and stronger evidence base than hydrochlorothiazide. NutriStack rates the supporting evidence as strong. Common adult dosing is 12.5–25 mg once daily (as prescribed by your physician), though a prescriber sets the actual dose. With long-term use it can deplete potassium, magnesium, zinc. This profile indexes 10 sources.

What it's good for
  • Superior 24-hour blood pressure control compared to HCTZ5
  • Proven cardiovascular event and stroke reduction (ALLHAT, SHEP)10,7
  • Long duration of action allows once-daily dosing
  • Low cost
What to watch for
  • Hypokalemia (more than HCTZ due to longer action)
  • Hyponatremia
  • Hyperuricemia and gout
  • Anuria
  • Hypersensitivity to chlorthalidone or sulfonamides1,2

The bottom line

Evidence rating strong. Most-documented uses: superior 24-hour blood pressure control compared to hctz, proven cardiovascular event and stroke reduction (allhat, shep), long duration of action allows once-daily dosing. 10 sources indexed (2021–2025), with 0 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

Inhibits sodium reabsorption at the distal convoluted tubule, similar to thiazides but with a longer duration of action. Also has some carbonic anhydrase inhibitory activity. Reduces plasma volume initially, then decreases peripheral vascular resistance with chronic use. Extensively binds to carbonic anhydrase in red blood cells, contributing to its long half-life.

Class
Thiazide-Like Diuretic
Dosing

Dosing & protocol.

Common range
12.5–25 mg once daily (as prescribed by your physician)
Recommended form
Oral tablet

Can be taken with or without food; take in the morning to avoid nocturia

Depletions

What it depletes.

Nutrients this medication can lower over time, and what to replace.

Potassium

Moderate

Thiazide diuresis can increase distal sodium delivery and urinary potassium secretion, so potassium should be monitored rather than self-repleted.

Replace Clinician-guided potassium repletion if serum potassium is lowMonitor Serum potassium + kidney functionOnset Can develop within days to weeks

Magnesium

Moderate

Thiazides can increase urinary magnesium losses and contribute to low magnesium status.

Replace Magnesium GlycinateMonitor Serum magnesium or RBC magnesiumOnset Usually over days to weeks

Zinc

Mild

Chronic thiazide use can increase urinary zinc excretion and gradually lower zinc balance.

Replace Zinc PicolinateMonitor Serum zincOnset Usually over weeks to months

Sodium

Moderate

Thiazides are a common medication cause of hyponatremia, especially in older adults.

Monitor Serum sodiumOnset Can develop within days to weeks

CoQ10

Mild

Beta-blocker and diuretic therapy are associated with lower CoQ10 status in some long-term users, likely through increased oxidative demand and reduced tissue levels.

Replace Coenzyme Q10Monitor Plasma CoQ10Onset Usually over months of chronic use

Full Chlorthalidone depletion and interaction guide →

Safety

Full safety detail.

Side effects

  • Hypokalemia (more than HCTZ due to longer action)
  • Hyponatremia
  • Hyperuricemia and gout
  • Hyperglycemia
  • Dizziness
  • Photosensitivity
  • Hyperlipidemia
  • Erectile dysfunction

Contraindications

  • Anuria
  • Hypersensitivity to chlorthalidone or sulfonamides1,2
  • Severe renal impairment (eGFR <30 mL/min, limited efficacy)
  • Severe hypokalemia or hyponatremia (uncorrected)
Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

5

Reference material

5
FAQ

Common questions.

Quick answers about Chlorthalidone, drawn from the data on this page.

What is Chlorthalidone?

Chlorthalidone is a thiazide-like diuretic with a longer half-life and stronger evidence base than hydrochlorothiazide. It was the diuretic used in the landmark ALLHAT and SHEP trials. Major guidelines increasingly favor chlorthalidone over HCTZ for hypertension due to superior 24-hour blood pressure control and proven cardiovascular event reduction.

What is Chlorthalidone used for?

Commonly cited benefits of Chlorthalidone include: Superior 24-hour blood pressure control compared to HCTZ; Proven cardiovascular event and stroke reduction (ALLHAT, SHEP); Long duration of action allows once-daily dosing; Low cost. NutriStack rates the overall evidence as strong.

What is a typical dose of Chlorthalidone?

A typical adult dose of Chlorthalidone is 12.5–25 mg once daily (as prescribed by your physician). The commonly recommended form is Oral tablet. These are general ranges, not personalized advice; confirm the right dose with a clinician.

What are the side effects of Chlorthalidone?

Reported side effects include hypokalemia (more than hctz due to longer action), hyponatremia, hyperuricemia and gout, hyperglycemia, dizziness, photosensitivity. This is educational information; check with a healthcare professional before use.

How strong is the evidence for Chlorthalidone?

NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.

Use this with your stack

Chlorthalidone in NutriStack.

Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.

Download on the App Store → Read the methodology

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.