NutriDex

The Supplement Research Compendium
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Lemon

Citrus limon

Citrate-rich citrus for stone prevention

Moderate evidence 🍎Fruits

✚ Updated · How we grade evidence

Evidence tier
Moderate
Research weight
Citations
10 verified / 10
Classification
Fruits
❝
What the evidence says. Several controlled trials; effects real but modest or context-dependent.

Nutrition per serving 1 medium (58 g)

58gSERVING
  • Water 51.6 g89%
  • Sugars 1.5 g3%
  • Fibre 1.6 g3%
  • Other carbs 2.3 g4%
  • Protein 0.6 g1%
  • Fat 0.2 g0%
What's in one serving, by weight — average composition (USDA).
Vitamin C34%Fiber6%Potassium2%Folate2%Calcium1%Vitamin B63%
One serving as % of the adult daily requirement (FDA Daily Values). The bold outer ring = 100% of a day's needs.
17 kcal0.6 g protein1.6 g fiber0.2 g fat
NutrientPer serving% daily value
Vitamin C31 mg34%
Fiber1.6 g6%
Potassium80 mg2%
Folate6.4 mcg2%
Calcium15 mg1%
Vitamin B60.05 mg3%
Copper0.02 mg2%
Magnesium4.6 mg1%

Composition data: USDA FoodData Central ↗

What is Lemon?

Lemon (Citrus limon) is a fruit used for raises urinary citrate and ph, reducing calcium kidney-stone risk. NutriDex grades the human evidence as Moderate. The strongest human evidence for lemon concerns kidney-stone prevention: small clinical studies show lemon/lemonade reliably raises urinary citrate (an endogenous stone inhibitor) and urine pH, with one prospective randomized study finding lemon juice comparable to potassium citrate and better tolerated. Most of these trials are small, short, and often without hard stone-recurrence endpoints, so lemon is best viewed as adjunctive rather than first-line therapy. Lemon's vitamin C and citric acid also enhance non-heme iron absorption, a well-established mechanism. Cardiovascular benefits derive largely from citrus flavanones such as hesperidin, where RCTs (mostly in orange juice) and meta-analyses show modest reductions in blood pressure and improved lipid/endothelial markers; lemon-specific cardiovascular trials are sparse and small. A standardized lemon-flavonoid nutraceutical (eriocitrin) improved glucose and GLP-1 in prediabetes, but this used concentrated extracts, not whole fruit. Overall the evidence is moderate and mechanistically coherent for citrate/iron effects but thinner and largely extrapolated from citrus generally for cardiometabolic claims.

Purported Benefits

✓Raises urinary citrate and pH, reducing calcium kidney-stone risk
✓Vitamin C supports immune function and collagen synthesis
✓Citrus flavanones (hesperidin) modestly improve blood pressure and endothelial function
✓Enhances non-heme iron absorption when consumed with meals
✓Lemon flavonoids may improve glycemic markers and GLP-1 in prediabetes
✓Antioxidant phytochemicals counter oxidative stress

Dosing & Compounds

Typical Dose
1 medium lemon (~58 g) or 2-4 oz juice daily; lemonade therapy uses ~4 oz reconstituted juice in 2 L water/day
Active Compounds
Citric acid (signature organic acid; ~5x orange juice)Vitamin C / L-ascorbic acidFlavanones: hesperidin, eriocitrin, naringinFlavones: diosmin, diosmetinLimonoids: limonin, nomilinPectin (soluble fiber, in peel/pith)PotassiumMonoterpenes: D-limonene, beta-pinene (peel oil)Coumarins

Safety & Cautions

High acidity can erode dental enamel and aggravate GERD or mouth ulcers; rinse with water after consuming. Citric/ascorbic acid may worsen reflux in sensitive individuals. Peel oils (limonene, psoralens/furanocoumarins) can cause phytophotodermatitis on sun-exposed skin. Grapefruit-style CYP3A4 drug interactions are minimal with lemon, but caution with furanocoumarin-containing peel. Generally very safe as food; concentrated flavonoid supplements lack long-term safety data. Educational only — always check with your doctor or pharmacist before combining Lemon with any medicine.

Key Studies ★ 10 studies

Meta-analysis Nabi 2025 ✓ Source
Systematic review and meta-analysis of citrus juice clinical trials found significant increases in urinary citrate and pH versus control, supporting calcium-stone risk reduction.
Meta-analysis Huang 2023 ✓ PubMed
Meta-analysis of 12 RCTs (589 participants) found hesperidin extracts improved LDL and total cholesterol, fasting glucose, and inflammatory markers (CRP, adhesion molecules).
RCT Ramos 2023 ✓ PubMed
Double-blind RCT: lemon-flavonoid nutraceutical (Eriomin, eriocitrin) reduced hyperglycemia 6% and increased blood GLP-1 22% in prediabetes, with gut microbiota shifts.
RCT Valls 2020 ✓ Full text
CITRUS RCT (n=159): hesperidin-enriched orange juice reduced systolic and pulse pressure dose-dependently (SBP -6.4 to -7.4 mmHg) over 12 weeks in pre/stage-1 hypertensives.
Clinical trial Seltzer 1996 ✓ PubMed
Lemonade (4 oz lemon juice = 5.9 g citric acid in 2 L/day) more than doubled urinary citrate (142 to 346 mg/day) without raising urine volume in hypocitraturic stone formers.
RCT Aras 2008 ✓ PubMed
Prospective randomized study found fresh lemon juice raised urinary citrate 2.5-fold (vs 3.5-fold for potassium citrate), supporting lemon juice as a tolerable alternative in hypocitraturic calcium-stone patients.
Prospective cohort Cassidy 2012 ✓ PubMed
In 69,622 women (Nurses' Health Study), highest vs lowest flavanone (citrus) intake was associated with 19% lower ischemic stroke risk (RR 0.81, 95% CI 0.66-0.99).
Observational Kato 2014 ✓ Full text
Observational study of 101 middle-aged women found daily lemon intake correlated negatively with systolic blood pressure (mechanism linked to blood citric acid).
Retrospective cohort Penniston 2007 ✓ PubMed
Lemonade therapy increased urinary citrate (+203 mg/day alone; +346 mg/day with potassium citrate) and urine volume in recurrent calcium-oxalate stone formers over ~40 months.
Retrospective cohort Kang 2007 ✓ PubMed
Long-term lemonade therapy in hypocitraturic stone formers raised urinary citrate (+mean 383 mg/day) and reduced stone formation rate from 1.0 to 0.13 stones/patient/year over ~44 months.
10 sources cited · 10 verified Search all studies on PubMed ↗

Common questions about Lemon

What is Lemon used for?

Lemon is most often taken for Raises urinary citrate and pH, reducing calcium kidney-stone risk, Vitamin C supports immune function and collagen synthesis, Citrus flavanones (hesperidin) modestly improve blood pressure and endothelial function, Enhances non-heme iron absorption when consumed with meals. Citrate-rich citrus for stone prevention

Does Lemon work — what does the evidence say?

Moderate evidence. Several controlled trials; effects real but modest or context-dependent. The strongest human evidence for lemon concerns kidney-stone prevention: small clinical studies show lemon/lemonade reliably raises urinary citrate (an endogenous stone inhibitor) and urine pH, with one prospective randomized study finding lemon juice comparable to potassium citrate and better tolerated. Most of these trials are small, short, and often without hard stone-recurrence endpoints, so lemon is best viewed as adjunctive rather than first-line therapy. Lemon's vitamin C and citric acid also enhance non-heme iron absorption, a well-established mechanism. Cardiovascular benefits derive largely from citrus flavanones such as hesperidin, where RCTs (mostly in orange juice) and meta-analyses show modest reductions in blood pressure and improved lipid/endothelial markers; lemon-specific cardiovascular trials are sparse and small. A standardized lemon-flavonoid nutraceutical (eriocitrin) improved glucose and GLP-1 in prediabetes, but this used concentrated extracts, not whole fruit. Overall the evidence is moderate and mechanistically coherent for citrate/iron effects but thinner and largely extrapolated from citrus generally for cardiometabolic claims.

What is the typical dose of Lemon?

1 medium lemon (~58 g) or 2-4 oz juice daily; lemonade therapy uses ~4 oz reconstituted juice in 2 L water/day

Is Lemon safe? Any cautions or side effects?

High acidity can erode dental enamel and aggravate GERD or mouth ulcers; rinse with water after consuming. Citric/ascorbic acid may worsen reflux in sensitive individuals. Peel oils (limonene, psoralens/furanocoumarins) can cause phytophotodermatitis on sun-exposed skin. Grapefruit-style CYP3A4 drug interactions are minimal with lemon, but caution with furanocoumarin-containing peel. Generally very safe as food; concentrated flavonoid supplements lack long-term safety data.

How many studies support Lemon?

NutriDex cites 10 sources for Lemon, graded "Moderate".

Cite this page
APA

Peh, D. (2026). Lemon (Citrus limon): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/lemon

BibTeX
@misc{nutridex_lemon,
  author       = {Peh, Daryl},
  title        = {Lemon (Citrus limon): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/lemon},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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