Lemons: Nutrition, Benefits, Peel and What to Watch

Lemons are bright yellow citrus fruits valued for their sour juice and fragrant peel. One small raw lemon has about 17 calories and around a third of the Daily Value for vitamin C in USDA data, which makes lemon nutrition good for the calories even though most people use only a squeeze at a time. The lemon benefits that hold up are practical: vitamin C, help absorbing iron from plant foods, a lot of flavor without added salt or sugar, and a peel that holds more fiber and vitamin C than the juice. This guide gives the USDA numbers for the fruit, juice and peel, sorts real lemon benefits from myths, and covers the cautions worth knowing for teeth and reflux.

Peptide Labs does not sell lemons or lemon products. This article is general nutrition information, not medical advice.

Lemon nutrition: USDA values for fruit, juice and peel

These values come from USDA SR Legacy: Lemons, raw, without peel (FDC 167746); Lemon juice, raw (FDC 167747); Lemon juice from concentrate, canned or bottled (FDC 167748); and Lemon peel, raw (FDC 167749). Percent Daily Values use the FDA Daily Values for adults.

Per 100 grams, USDA lists 53 milligrams of vitamin C for lemon flesh, about the same as an orange (53.2 milligrams in the USDA entry for raw oranges), with far less sugar: 2.5 grams versus 9.4 grams. Lemons also add small amounts of folate (3% DV per 100 grams), vitamin B6, potassium and calcium. The biggest surprise is the peel: per 100 grams, the USDA entry for raw lemon peel lists 10.6 grams of fiber and 129 milligrams of vitamin C, against 0.3 grams and 38.7 milligrams for raw lemon juice. You eat little peel at a time, but grated zest is a real addition, not just decoration.

Fresh beats bottled for vitamin C. Per 100 grams, bottled lemon juice from concentrate lists 14.3 milligrams in USDA data, against 38.7 milligrams for fresh juice, and some bottled products add sodium or preservatives, so check the label. For lime numbers, see our limes guide, which includes a lime vs lemon table.

Lemon benefits backed by evidence

• Vitamin C: the NIH Office of Dietary Supplements (ODS) names citrus fruits among the top food sources of vitamin C and among the major contributors in the American diet. Adult RDAs per ODS are 90 milligrams for men and 75 milligrams for women. Our vitamin C food list ranks lemons against other produce, and our vitamin C supplement guide covers pills.
• Iron from plant foods: ODS notes that vitamin C improves absorption of nonheme iron, the form in beans, lentils and greens. Lemon juice on a lentil salad is a classic pairing; see our foods high in iron guide.
• Flavor without salt or sugar: acidity brightens food, so a squeeze of lemon can make plain vegetables, fish or water more appealing. That is a cooking benefit, not a medical one.
• Citric acid: a 2008 Journal of Endourology analysis found lemon and lime juice to be rich sources of citric acid, more than orange or grapefruit juice, while bottled lemonade drinks held far less. Citrate in urine is studied in kidney stone care; if you have had stones, ask your clinician before relying on lemon juice, and see our potassium citrate article for the prescription side.

Lemons also played a part in the history of nutrition. ODS recounts that in the mid-1700s James Lind, a British Navy surgeon, found that citrus fruits or juices helped sailors with scurvy, although ascorbic acid was not proved to be the active factor until 1932.

Lemon myths that do not hold up

• Detox: no human evidence shows that lemons clear toxins or cleanse any organ.
• Alkalizing your blood: no good human evidence shows lemons change blood pH, and lemon juice itself is strongly acidic.
• Fat burning: no trial shows lemons cause weight loss. What the research on drinking water and citrus water found is summarized in our lemon water article.
• Supplement extracts: some capsules list lemon fruit extracts standardized to eriocitrin, a lemon flavonoid. A concentrated extract is not the same as eating lemons, and studies of one do not apply to the other.

Lemons also share a name with plants that are not lemons at all. Lemon balm is a mint-family herb with its own research, covered in our lemon balm guide, and ginger with lemon is a separate drink topic in our ginger tea article.

Are lemons healthy? Cautions for teeth and reflux

• Tooth enamel: the FDA lists lemon juice at about pH 2.0 to 2.6. The American Dental Association names lemon, lime and orange among the sources of acid in drinks and notes that even fresh-squeezed lemonade is more acidic than water. Its tips: use a straw, rinse with water or have milk or cheese afterward, and wait an hour before brushing.
• Research on erosion: a 2025 meta-analysis of studies in children up to age 7 linked frequent acidic food and drinks, and holding drinks in the mouth, with erosive wear of baby teeth; the studies were observational.
• Heartburn: NIDDK lists citrus fruits among foods commonly linked to reflux symptoms. If lemon sets off heartburn, our bland diet guide lists gentler options; frequent heartburn deserves a clinician visit.
• Skin and sun: citrus juices contain furocoumarins, and burn-like sun rashes after citrus contact are reported, mostly with limes. Rinse juice off your skin before sun exposure.
• Allergy: citrus is not one of the nine major food allergens on US labels, but reactions occur. Urgent symptoms need urgent care; see our elimination diet guide for why testing should be supervised.

Using lemon peel and choosing lemons

Choose lemons that feel heavy for their size, with bright, firm skin; thin-skinned lemons usually give more juice. Whole lemons keep longer in the refrigerator. To use the peel, scrub the fruit, then grate only the yellow zest; the white pith underneath is bitter. Zest freezes well, and zesting before juicing gets two ingredients from one fruit. Meyer lemons, sold in some stores in winter, are sweeter and less acidic than standard lemons.

For other fruits with plenty of vitamin C and fiber, see our kiwi and strawberries guides, and our antioxidant foods list.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Limes: Nutrition, Lime vs Lemon, Key Limes and Safety, Lemon Water Benefits: Hydration, Teeth and What Studies Show, Foods High in Vitamin C: USDA List of Fruits and Vegetables, Citrus Fruits: Types, Botany and USDA Nutrients per Fruit.