The Quick Answer
For the majority of healthy adults, drinking alkaline water has no significant side effects. Your body is remarkably good at regulating its own pH, and your kidneys, lungs, and blood buffer systems handle minor changes in the pH of what you consume without breaking a sweat.
That said, there are a small number of situations where caution is warranted. We believe you deserve to know about them, not because alkaline water is dangerous, but because informed choices are always better than blind ones.
Key Context
Most research on alkaline water shows it is safe for general consumption. The side effects listed below are either mild and temporary, or apply only to specific medical conditions. We cover them all so you can make a fully informed decision.
Potential Side Effects (Honest Breakdown)
Let us walk through each reported side effect, how common it is, who it affects, and what you should do if it happens.
Mild & Temporary
Some people report mild nausea, slight headaches, or a change in bowel habits when they first switch from regular tap or purified water to alkaline water. This is particularly common when people make a sudden switch rather than a gradual one.
These symptoms typically resolve within a few days to a week as your body adjusts. They are similar to what people experience when making any significant change to their diet or hydration routine.
Uncommon
Your stomach produces hydrochloric acid (pH 1.5 to 3.5) to break down food and kill harmful bacteria. There is a theoretical concern that drinking large amounts of high-pH water could temporarily raise the stomach’s pH, potentially affecting digestion.
In practice, your stomach is very good at maintaining its acidity. It responds to any pH increase by producing more acid. For healthy people drinking normal amounts, this is a non-issue. However, people who already have low stomach acid (hypochlorhydria) or conditions like atrophic gastritis may want to be more mindful.
Context-Dependent
Some medications rely on a specific stomach pH for proper absorption. This includes certain blood pressure medications, antibiotics, and drugs for bone density. Drinking alkaline water close to the time you take these medications could, in theory, affect how well they are absorbed.
This is not unique to alkaline water. Antacids, dairy products, and even some foods can have the same effect. The simple solution is timing: take your medication with regular water and drink alkaline water at other times of the day.
Speak to Your Doctor
If you take prescription medication, talk to your doctor or pharmacist before making alkaline water your primary drinking water. They can advise on timing and any specific concerns for your medication.
Extremely Rare
Metabolic alkalosis occurs when the blood becomes too alkaline (pH above 7.45). Symptoms can include nausea, vomiting, hand tremors, muscle twitching, and confusion. It sounds alarming, and it would be dishonest not to mention it.
However, context matters enormously here. Metabolic alkalosis from drinking water alone is virtually unheard of in medical literature. The condition is almost always caused by excessive intake of alkaline supplements (like baking soda), prolonged vomiting, or certain medical conditions. Drinking alkaline water with a pH of 8 to 10 does not deliver enough alkalinity to override your body’s tightly controlled buffer systems.
Who Should Be Cautious
While alkaline water is safe for most people, certain groups should consult with a healthcare professional before making it a regular part of their routine.
Consult Your Healthcare Provider First
The groups listed below are not necessarily at risk. But because their health situations are more complex, a quick conversation with a doctor is the responsible step before any dietary change.
People with Kidney Disease
Healthy kidneys filter and excrete excess minerals with ease. However, when kidney function is compromised (as in chronic kidney disease), the body may struggle to process additional minerals like calcium, magnesium, and potassium that are naturally present in alkaline water. If you have been diagnosed with any stage of CKD, speak to your nephrologist.
People on Specific Medications
As discussed above, medications that depend on stomach pH for absorption may be affected. This includes certain drugs for blood pressure, thyroid conditions, bone density, and some antibiotics. Your pharmacist is the best person to ask about your specific medications.
Infants and Very Young Children
Babies have developing digestive systems and different mineral requirements than adults. Formula preparation should follow the manufacturer’s instructions regarding water type. For infants, regular purified or boiled water is the standard recommendation. Once children are older and eating a varied diet, alkaline water is generally considered safe, but ask your paediatrician if you are unsure.
People with Certain Digestive Conditions
If you have been diagnosed with achlorhydria (absence of stomach acid) or hypochlorhydria (very low stomach acid), drinking large amounts of alkaline water may not be ideal, as your stomach already struggles to maintain the acidity needed for digestion. These are relatively uncommon conditions, usually diagnosed and managed by a gastroenterologist.
For Most People, Alkaline Water is Safe
We have been transparent about the edge cases. Now let us put this in perspective.
Millions of people around the world drink alkaline water every day. It is sold in supermarkets, pharmacies, and health stores across dozens of countries. In South Africa alone, alkaline water has been a growing category for over a decade, with no pattern of adverse health events.
The Bottom Line
If you are a generally healthy adult with no kidney disease and no medications that interact with stomach pH, alkaline water is considered safe to drink daily. Your body’s buffering systems are designed to handle variations in the pH of what you consume.
Your body maintains blood pH within a very tight range (7.35 to 7.45) regardless of what you eat or drink. This is not a weakness. It is one of the most robust systems in human physiology. Alkaline water does not override this system. What it does provide is hydration with naturally occurring minerals like calcium, magnesium, and potassium, in a form that many people find tastes better and feels smoother.
A 2012 study published in The Annals of Otology, Rhinology & Laryngology (Koufman & Johnston) found that water with a pH of 8.8 may have additional benefits for people with acid reflux, as it can denature the enzyme pepsin. While more research is needed, this is one of the areas where alkaline water shows genuine promise.
The key takeaway: alkaline water is not a medicine, and it is not a risk. For most people, it is simply a high-quality hydration choice.
What Makes Designer Water Different
Not all alkaline water is created equal. The quality, consistency, and safety of your water depend entirely on who produces it and how they are held accountable.
SANBWA Accredited
We are audited and accredited by the South African National Bottled Water Association. This means regular independent testing of our water quality, mineral content, and safety standards.
ISO 22000 Food Safety
Our facility operates under ISO 22000 certification, the international standard for food safety management systems. Every batch is traceable, every process is documented.
Consistent pH & Mineral Content
Our pH10 alkaline water delivers a consistent pH level and known mineral profile in every bottle. You always know exactly what you are drinking, unlike unregulated or home-ionised alternatives.
Kosher, Halal & GC Mark
We hold Kosher, Halal, and GC Mark of Conformity certifications. These are not marketing labels. They represent independent audits of our production processes, ingredients, and hygiene standards.
Known Mineral Content
Our water contains naturally occurring calcium (Ca), magnesium (Mg), and potassium (K) at tested and verified levels. You are not guessing about what minerals are in your water or at what concentration.
97.9% Blind Taste Test
In an independently conducted blind taste test, 97.9% of participants preferred Designer Water. Quality you can actually taste, backed by real data.
Frequently Asked Questions
For people with healthy kidneys, alkaline water is not harmful. Your kidneys are highly efficient at regulating blood pH regardless of what you drink. However, people with chronic kidney disease (CKD) should consult their doctor before making any dietary changes, including switching to alkaline water, because compromised kidneys may have difficulty processing the additional minerals.
Some people report mild nausea or an upset stomach when they first switch to alkaline water. This is typically a short-term adjustment period and usually resolves within a few days. If you experience persistent stomach discomfort, reduce your intake and gradually increase it over time. People with conditions that require high stomach acidity for proper digestion should speak to a healthcare provider.
There is no strong evidence that alkaline water is unsafe during pregnancy. Many pregnant women drink alkaline water without issues. However, pregnancy requires careful attention to nutrition and hydration, so it is always best to discuss any dietary changes with your obstetrician or midwife. The most important factor is staying well hydrated with clean, safe water.
There is no universally agreed-upon limit for alkaline water intake. Most health professionals recommend the same daily water intake guidelines regardless of pH: approximately 2 litres for women and 2.5 litres for men, adjusted for activity level and climate. If you are new to alkaline water, start with 2 to 3 glasses per day and increase gradually. For a more detailed guide, see our article on how much alkaline water to drink per day.
Both alkaline water and regular purified water will keep you hydrated. The key differences are mineral content and taste. Alkaline water naturally contains minerals like calcium, magnesium, and potassium, and many people prefer its smoother taste. Whether it is “better” depends on what you value. For hydration alone, both work. For mineral content and taste preference, many people choose alkaline. Learn more about the benefits of alkaline water.
Medical Disclaimer: The content on this page is for informational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult with a qualified healthcare professional before making changes to your diet or hydration routine, especially if you have a pre-existing medical condition or are taking medication. Designer Water makes no claims that its products treat, cure, or prevent any disease.