Making alkaline water with lemon is simple: squeeze half a fresh lemon into 8 ounces of room temperature or cool water and let it sit for a few minutes before drinking. This sounds counterintuitive since lemon juice is acidic, with a pH around 4.2. But once your body metabolizes it, lemon juice leaves behind alkaline byproducts that shift your urine toward a more basic pH.
Why Acidic Lemon Creates an Alkaline Effect
Lemon juice has a potential renal acid load (PRAL) of -2.5 per 100 grams. PRAL measures whether a food leaves acidic or alkaline residue after digestion. Negative values mean a food produces alkaline byproducts. Nearly all fruits and vegetables score negative on this scale, but lemons are a popular choice because they’re easy to add to water and drink throughout the day.
The key is what happens after digestion. Your body breaks down the citric acid in lemon juice and uses the minerals it contains, particularly potassium. Those minerals generate alkaline compounds that your kidneys process. The result is urine that’s slightly more alkaline than it would be otherwise. The lemon water itself isn’t alkaline sitting in your glass. The alkalizing effect happens inside your body.
What Lemon Water Can and Cannot Change
Your blood pH stays locked between 7.35 and 7.45 at all times. Healthy kidneys and lungs constantly work to keep it in that range, and no drink can safely push blood pH outside of it. Lemon water does not “alkalize your body” in the sweeping way that some wellness claims suggest. What it can do is make your urine more alkaline, which may offer some specific benefits.
A clinical trial of 203 patients with recurrent calcium oxalate kidney stones found that those who supplemented with fresh lemon juice had fewer stone recurrences. At the one-year mark, 10 patients in the lemon group experienced new stones compared to 22 in the control group, a statistically significant reduction of about 55%. The protective effect likely comes not from increased citrate in the urine, as researchers originally expected, but from decreased sodium concentration, which lowers the saturation levels that allow stones to form. The benefit was strongest in the first year, partly because patient adherence dropped from 68% to 48% by year two.
How to Prepare It
The process requires nothing more than fresh lemons and water. Squeeze the juice of half a lemon (roughly one tablespoon) into a glass of water. You can use warm, room temperature, or cold water based on preference. Some people add a full lemon’s worth of juice for a stronger flavor. Stir briefly and drink.
A few practical tips make this easier to sustain:
- Use fresh lemons. Bottled lemon juice often contains preservatives and may lack the full range of beneficial compounds found in fresh fruit.
- Drink it in the morning. Many people find it easiest to build the habit by having lemon water first thing, before coffee or breakfast.
- Use a straw. This minimizes contact between the acidic liquid and your tooth enamel.
- Wait before brushing. Brushing immediately after drinking something acidic can spread the acid across softened enamel. Wait at least 30 minutes, or rinse your mouth with plain water first.
Protecting Your Teeth
The biggest practical risk of drinking lemon water regularly is enamel erosion. Lemon juice has a pH around 4.2, and tooth enamel begins to soften below a pH of about 5.5. Diluting lemon juice in a full glass of water raises the pH considerably, but the drink is still acidic enough to cause gradual damage with daily exposure.
Drinking through a straw, rinsing your mouth with plain water afterward, and avoiding swishing the lemon water around your mouth all reduce enamel contact. If you use fluoride toothpaste or mouthwash, that also helps strengthen enamel against acid wear. The key factor is frequency: sipping lemon water throughout the entire day exposes your teeth to prolonged acid contact, while drinking it in one sitting and rinsing afterward limits the window of exposure.
Lemon Water vs. Baking Soda
Baking soda is the other common method people use to make water more alkaline. Unlike lemon, baking soda actually makes the water itself alkaline in the glass. Dissolving half a teaspoon in water creates a solution with a pH above 7. But this approach comes with significant trade-offs.
A single teaspoon of baking soda contains about 1,200 mg of sodium, more than half the recommended daily intake for most adults. Regular use can contribute to elevated blood pressure, fluid retention, and added strain on the heart and kidneys. In people with kidney problems, overuse can cause electrolyte imbalances and a condition called metabolic alkalosis, where blood becomes too alkaline, leading to confusion, muscle twitching, and nausea.
Baking soda can also cause digestive side effects including gas, bloating, stomach cramps, and acid rebound, where heartburn temporarily improves but then worsens. Lemon water avoids these sodium-related risks entirely. Its main downsides are the enamel concern and the sour taste, both of which are manageable.
Other Health Benefits of Lemon Water
Beyond its alkalizing effect on urine, lemon water provides a modest dose of vitamin C and keeps you hydrated, which is arguably its most underrated benefit. Many people who start drinking lemon water simply end up drinking more water overall because the flavor makes it more appealing.
Lemon peel contains polyphenols that have shown promising effects in animal research. In one study, mice fed a high-fat diet supplemented with lemon polyphenols had significantly less body weight gain, less fat accumulation, and lower blood sugar and insulin levels compared to mice on the same high-fat diet without the polyphenols. The polyphenols appeared to activate fat-burning pathways in both the liver and fat tissue. These results haven’t been confirmed in human clinical trials, though, and the concentrations used in animal studies are difficult to replicate by simply adding lemon juice to water. Most of the polyphenols studied were extracted from lemon peel, not the juice itself.
If you want to capture more of these compounds, you can add thin slices of lemon (with the peel on) to your water instead of just squeezing the juice. Use organic lemons if you go this route, since conventional lemon peels may carry pesticide residue. Wash them thoroughly either way.