Limes: Nutrition, Lime vs Lemon, Key Limes and Safety

Limes are small, sour green citrus fruits used far more for their juice and zest than eaten whole. One raw lime has about 20 calories and supplies roughly a fifth of the Daily Value for vitamin C, according to USDA data, but lime nutrition is modest overall because people use so little at a time. In the lime vs lemon question, the two have almost the same calories, fiber and acidity, while lemons carry close to twice the vitamin C per 100 grams. Below are the USDA numbers for limes and lime juice, a side-by-side comparison with lemons, what the evidence does and does not support, and one safety issue that is specific to limes: a blistering rash when lime juice on the skin meets sunlight.

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

What are limes? Persian limes and key limes

Most limes sold in US supermarkets are Persian (also called Tahiti or Bearss) limes: fairly large, seedless or nearly so, with a thick green rind that turns yellow-green as the fruit ripens. Key limes, also sold as Mexican limes, are smaller and rounder, with thin skin, more seeds and a sharper, more aromatic juice. They are the traditional choice for key lime pie, although many recipes and bottled products use Persian lime juice instead.

Both are used the same way in the kitchen: juice for drinks, dressings, marinades and salsas, and the zest (the colored outer layer of the rind) for aroma. Makrut (kaffir) lime leaves used in Thai cooking come from a different citrus tree and are used as an herb, not for juice.

Lime nutrition facts from USDA

The table uses the USDA SR Legacy database: Limes, raw (FDC 168155); Lime juice, raw (FDC 168156); and Lime juice, canned or bottled, unsweetened (FDC 168157). Percent Daily Values use the FDA Daily Values for adults.

A whole lime also gives small amounts of calcium (2% DV), copper (5% DV), iron and folate in USDA data. The most useful takeaway is the gap between fresh and bottled juice: per 100 grams, the USDA entry for bottled lime juice lists about a fifth of the vitamin C of fresh lime juice. Vitamin C breaks down with heat, long storage and processing, a point the NIH Office of Dietary Supplements (ODS) makes about foods in general. If you want the vitamin C, squeeze the fruit.

Lime vs lemon: how they compare

Limes and lemons are close relatives and can often stand in for each other in recipes. Here is how the raw fruits compare per 100 grams in USDA SR Legacy (Limes, raw, FDC 168155; Lemons, raw, without peel, FDC 167746).

Acidity is a near tie. The FDA’s table of approximate food pH values puts lime juice at 2.00 to 2.35 and lemon juice at 2.00 to 2.60. A 2008 analysis in the Journal of Endourology measured citric acid in fresh juices and commercial drinks and found lemon and lime juice nearly equal and well above orange and grapefruit juice, while ready-to-drink lemonade products held far less. Our guide to lemons covers the lemon side in more depth.

Flavor is the real difference: limes taste more bitter and floral, lemons brighter and slightly sweeter. For more on fruits with little sugar, see our low-sugar fruits list.

Lime benefits: what the evidence supports

Honest lime benefits are about nutrients and cooking, not medicine. The ODS fact sheet names citrus fruits among the top food sources of vitamin C, and it notes that vitamin C improves absorption of nonheme iron, the form found in plant foods. A squeeze of lime over beans or greens is a simple way to pair the two; our foods high in iron guide explains heme and nonheme iron, and our vitamin C food list shows where limes rank against peppers, kiwi and oranges.

Limes also hold a famous and slightly ironic place in nutrition history. ODS recounts that in the mid-1700s James Lind, a British Navy surgeon, found that citrus fruits or juices helped sailors with scurvy, the disease of severe vitamin C deficiency. A 2009 history review in Nutrition Reviews adds that after lime juice was substituted for lemon juice in about 1860, scurvy came back, especially on polar expeditions. That fits the USDA numbers above: per 100 grams, limes carry about half the vitamin C of lemons.

Claims that limes detox the body, alkalize your blood or melt fat are not backed by human evidence. Lime juice in water adds flavor to a drink people may sip more of; our lemon water article reviews what the research on citrus water actually found.

Lime juice and margarita photodermatitis

Limes have one safety issue that lemons rarely produce in the medical literature. Lime peel and juice contain furocoumarins (psoralens), plant compounds that make skin react to ultraviolet light. When lime juice stays on the skin and the skin is then exposed to sun, the result can be phytophotodermatitis, nicknamed margarita photodermatitis or margarita burn. The New England Journal of Medicine published a case under that name in 1993, and the reports keep coming: a 2021 Journal of the American Board of Family Medicine case described a 26-year-old woman who handled citrus for margaritas outdoors, and a 2025 case report described a striped dark patch on a woman’s forearm after she spilled a mojito in the sun.

• What it looks like: red patches, sometimes blisters that resemble a second-degree burn, often in drip, streak or handprint shapes, followed by brown discoloration that can last for weeks or months.
• Why it is missed: the case authors note it is often mistaken for allergic rashes, sunburn, burns, cellulitis or even abuse, because the shapes look odd.
• Practical point: the reports describe juice on skin followed by sun. Washing lime juice off your hands and arms before heading outside removes that trigger. A painful or blistering rash deserves a visit to a clinician.

Teeth, reflux and allergy

• Teeth: the American Dental Association lists lime, lemon and orange among the sources of acid in beverages. Its tips: sip acidic drinks through a straw, rinse with water or have milk or cheese afterward, and wait an hour before brushing. A 2025 meta-analysis of studies in young children linked frequent acidic food and drinks with erosive wear of baby teeth (an association, not proof of cause).
• Reflux: the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) lists citrus fruits among foods commonly linked to heartburn symptoms; people with reflux often notice their own triggers. See our bland diet guide.
• Allergy: citrus is not one of the nine major food allergens on US labels, but citrus allergy exists. Swelling, hives or breathing trouble needs urgent care; for unclear reactions, see an allergist (our elimination diet guide explains why testing should be supervised).

Choosing and storing limes

Pick limes that feel heavy for their size and give slightly when pressed; heavy fruit usually has more juice. A little yellow on a Persian lime is normal ripening. Whole limes keep longer in the refrigerator than on the counter, and rolling a lime firmly on the counter before cutting makes it easier to juice. Zest before you juice, and scrub the rind first if you plan to use it.

Frequently Asked Questions

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Last reviewed October 2026.

Related guides: Lemons: Nutrition, Benefits, Peel and What to Watch, Foods High in Vitamin C: USDA List of Fruits and Vegetables, Lemon Water Benefits: Hydration, Teeth and What Studies Show.