Kidney Diet 7 min read·Updated 4 October 2026 Clinician-reviewed

Is Barley Water Good for Your Kidneys?

A UK Consultant Nephrologist on barley water — a British household remedy for 'kidney trouble' with a long history and thin evidence.

  • Clinically Reviewed
  • NHS & NICE Aligned
  • UK Evidence-Based
  • Last Reviewed 4 October 2026

Professor Mohammed Mahdi Althaf

Consultant Nephrologist & Acute Physician

View Credentials

Professor Mohammed Mahdi Althaf

MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN

Consultant Nephrologist & Acute Physician · GMC 7216325

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Direct answer

Barley water is a pleasant, low-potassium way to drink more fluid. That is the whole benefit — it does not cleanse the kidneys or dissolve stones. Pick a no-added-sugar squash and check for potassium-based ingredients.

Key recommendation: No clinical evidence for improving kidney function.

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Quick answer

✓ Best choices

  • Vegetables and lower-potassium fruit at every meal
  • Whole grains: oats, basmati rice, pasta, wholegrain bread
  • Lean protein in modest portions: fish, chicken, eggs, tofu
  • Extra virgin olive oil, herbs and spices for flavour

✓ Foods to limit

  • Added salt and salty sauces
  • Processed meats and foods with phosphate additives (E338–E452)
  • Very large portions of bananas, oranges, potatoes if potassium is rising

Key takeaway

Barley water is a pleasant, low-potassium way to drink more fluid. That is the whole benefit — it does not cleanse the kidneys or dissolve stones. Pick a no-added-sugar squash and check for potassium-based ingredients.

Who should be cautious

People on dialysis, post-transplant, pregnant or breastfeeding, or taking prescription medication — confirm with your renal team before changes.

Is Barley Water Good for Your Kidneys?

Where the tradition comes from

Barley water was recommended for centuries for 'gravel' and urinary complaints, long before we could measure kidney function. In practice, anyone drinking barley water was drinking more fluid, which genuinely reduces stone formation and helps flush bacteria during urinary infections. The barley itself has never been shown to do anything specific for the kidney.

Choosing a version in the UK

  • No-added-sugar lemon barley squash, diluted 1:5 — lowest sugar, low potassium.
  • Standard barley water squash — fine occasionally; ~ 20 g sugar per 250 ml made up.
  • Homemade (pearl barley simmered in water, strained, lemon added) — more potassium leaches into the liquid; keep to a glass or two a day if potassium is restricted.
  • Always check labels of 'reduced sodium' drinks for potassium chloride.

If you have a fluid restriction

On dialysis, barley water counts fully towards your allowance. Its flavour can, however, make a small volume more satisfying than plain water — try it very cold or frozen into cubes.

How Much Water Should I Drink with Kidney Disease?
Related reading: How Much Water Should I Drink with Kidney Disease?.

Key practical tips

Designed for quick scanning — what to order, what to avoid, sensible portions, common mistakes.

  • Read labels: sodium ≤ 0.3 g per 100 g (low) is the target
  • Cook from scratch when you can — it controls the hidden salt and phosphate
  • Personalise potassium and phosphate targets with your renal dietitian

Clinical guidance

TL;DR summary

Barley water is a pleasant, low-potassium way to drink more fluid. That is the whole benefit — it does not cleanse the kidneys or dissolve stones. Pick a no-added-sugar squash and check for potassium-based ingredients.

Key takeaways
  • No clinical evidence for improving kidney function.
  • Diluted squash is low in potassium and phosphate.
  • Homemade boiled barley water is higher in potassium.
  • Choose no-added-sugar if you have diabetes.
  • Fluid volume is what helps stones and UTIs, not the barley.
Kidney Diet & Nutrition Considerations

On a kidney-friendly diet, single foods matter less than the overall pattern. Build meals around vegetables, lower-potassium fruit, whole grains, sensible protein and olive oil, and watch the three usual suspects — salt, phosphate additives and oversized portions of very high-potassium foods. Targets are individual and should be confirmed with your renal team.

Foods to prioritise

  • Vegetables and lower-potassium fruit at every meal
  • Whole grains: oats, basmati rice, pasta, wholegrain bread
  • Lean protein in modest portions: fish, chicken, eggs, tofu
  • Extra virgin olive oil, herbs and spices for flavour

Foods to limit

  • Added salt and salty sauces
  • Processed meats and foods with phosphate additives (E338–E452)
  • Very large portions of bananas, oranges, potatoes if potassium is rising

Potassium, phosphate and protein needs vary between individuals — please confirm personal targets with your renal team or dietitian. Browse the Kidney Diet Hub for more guides in this cluster.

Frequently asked questions

Is barley water good for kidneys?

There is no clinical evidence that barley water improves kidney function or clears stones. Its benefit is simply that it encourages people to drink fluid, which matters for urine infections and stone prevention.

Is Robinsons barley water OK in CKD?

Diluted squash is low in potassium and phosphate, so it fits most renal diets. Choose no-added-sugar versions if you have diabetes, and check that any 'low salt' variant does not use potassium chloride.

Does barley water help kidney stones?

Only through fluid volume. Aiming for 2–2.5 litres of urine a day is the proven stone measure — the drink itself is not special.

Is barley water high in potassium?

Commercial diluted barley squash is low in potassium. Homemade barley water made by boiling pearl barley extracts more potassium, so use it in moderation if potassium is restricted.

What foods are best for kidney health?

A kidney-friendly diet centres on vegetables, lower-potassium fruit (apples, pears, berries), whole grains (oats, basmati rice, pasta), sensible portions of fish, eggs or lean meat, beans and lentils in modest portions, and olive oil as the main cooking fat — broadly a Mediterranean pattern with reduced salt.

Nutritional challenges in kidney disease

Many people living with kidney disease have to limit foods because of potassium, phosphate, diabetes, dialysis, appetite changes or simply the time it takes to cook from scratch every day. That can make it harder to keep daily nutrition balanced — particularly for vitamins and minerals that food alone may not fully cover.

Kidney Vitality is a UK-formulated daily nutritional support product designed by Consultant Nephrologist Professor Mohammed Mahdi Althaf with renal nutrition in mind from the start. It keeps doses moderate, leaves out added potassium, phosphate and magnesium, and avoids megadose vitamin A — sitting alongside a kidney-friendly diet, not replacing it.

Why Kidney Vitality fits this need

Built around UK renal guidance

Aligned with NICE NG203, KDOQI 2020 and BDA renal nutrition guidance.

Designed by a UK Consultant Nephrologist

Formulated and reviewed by Professor Mohammed Mahdi Althaf (GMC 7216325).

Evidence-based by design

No added potassium or phosphate; sensible vitamin doses.

Designed by a UK Consultant Nephrologist

Ready to support your kidney health?

If you have been researching kidney health, supplements, CKD nutrition or kidney-friendly living, Kidney Vitality was developed specifically around those principles by Professor Mohammed Mahdi Althaf (GMC 7216325). Nephrologist Developed Daily Multivitamin.

  • No Added Potassium
  • No Added Magnesium
  • No Added Phosphorus
  • No Added Iron
  • One capsule daily
  • UK GMP — BRCGS, NSF GMP, Halal
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ComparisonKidney VitalityTypical high-street multivitamin
Added potassiumNoneOften included
Added phosphateNoneOften included (E338–E452)
Vitamin A (retinol)No megadoseOften high-dose retinol
Kidney-focused formulationYesNo — general population
Consultant Nephrologist involvementYes (GMC 7216325)No
UK GMP manufacturedYes (BRCGS, NSF GMP)Varies

Food supplement. Not a medicine and not a treatment for kidney disease. Speak with your GP, pharmacist or renal team before starting any new supplement, especially in advanced CKD, on dialysis, post-transplant, pregnant or breastfeeding.

Recommended next

Clinical reviewer

Professor Mohammed Mahdi Althaf

Consultant Nephrologist

Acute Physician

GMC 7216325

View Full Biography

Professor Mohammed Mahdi Althaf is a UK Consultant Nephrologist and Acute Physician with a special interest in chronic kidney disease, AKI prevention and renal nutrition. He combines hospital practice with patient education and clinical guidance review.

View professional profile →
View Credentials
  • MD
  • MSc
  • PgDip (Clin Ed)
  • FRCP
  • FHEA
  • FASN

About this article

Written for UK patients and based on:

  • NICE guidance
  • NHS resources
  • British Dietetic Association guidance
  • Kidney Care UK resources
View methodology

Each article is researched against current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO and KDOQI international guidelines, and the British Dietetic Association Renal Nutrition Group. Drafts are written by the Kidney Vitality editorial team and reviewed by a UK Consultant Nephrologist before publication. Content is reviewed on a rolling basis and updated when guidance changes.

Editorial standards

  • Clinically reviewed
  • NHS-aligned
  • NICE-aligned
  • Evidence-based
  • Reviewed before publication
View full editorial process

Every article is researched and written by the Kidney Vitality editorial team using current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO/KDOQI international guidelines, and British Dietetic Association renal nutrition guidance. Drafts are reviewed for clinical accuracy by Professor Mohammed Mahdi Althaf, MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN (Consultant Nephrologist & Acute Physician, GMC 7216325) before publication. Content is updated when UK guidance changes.

References (4)View Sources
  1. NICE NG203: Chronic kidney disease — assessment and management
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
  3. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update
  4. British Dietetic Association — Renal Nutrition Group

Medical disclaimer

This content is educational only and does not replace personalised medical advice.

Read full disclaimer

This page is general information, not personal medical advice. If you have chronic kidney disease, are on dialysis, have had a kidney transplant, are pregnant or breastfeeding, or take prescription medication, please confirm any supplement with your GP, pharmacist or renal team before starting.

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