Why Am I Still Thirsty After Drinking Aquafina Water?

January 5, 2026 •

3 min read

According to the World Health Organization, adequate hydration is essential for bodily functions, but some people report feeling even thirstier after drinking certain bottled waters like Aquafina. This paradoxical sensation can be puzzling and is often linked to the specific purification process used, which removes not only contaminants but also essential minerals.

Quick Summary

Purified bottled water, like Aquafina, can sometimes leave a feeling of persistent thirst due to its low mineral content. The reverse osmosis process strips water of contaminants and beneficial electrolytes, which are crucial for cellular hydration. Proper rehydration involves replenishing both fluids and minerals for optimal fluid balance in the body. Certain factors beyond the water itself can also contribute to this lingering thirst.

Key Points

Reverse Osmosis: Aquafina's purification process removes beneficial minerals like electrolytes, which are crucial for cellular hydration.
Electrolyte Imbalance: Drinking large amounts of mineral-deficient water can disrupt your body's fluid balance, leading to a lingering feeling of thirst.
Hydration vs. Drinking: True hydration is about replenishing both water and electrolytes, not just consuming plain fluid.
Salty Foods: High-sodium diets can draw water from your cells, increasing the body's demand for fluid and causing thirst.
Medical Conditions: Persistent, excessive thirst can be a symptom of underlying conditions like diabetes and should be evaluated by a healthcare professional.
Enhance Hydration: Improve hydration by remineralizing water with electrolyte drops or consuming water-rich foods and balanced electrolyte beverages.

The Reverse Osmosis Process and Your Thirst

Aquafina utilizes a rigorous seven-step purification process called HydRO-7, with reverse osmosis (RO) as a key stage. This process forces water through a semi-permeable membrane to remove dissolved solids, salts, and other impurities. While this results in incredibly pure water with a very low Total Dissolved Solids (TDS) reading, it also strips out the beneficial electrolytes like magnesium, calcium, and potassium that are naturally found in water.

The Science of Hydration and Electrolytes

True hydration is more than just consuming water; it is about maintaining a proper fluid and electrolyte balance within the body. Our cells need electrolytes to effectively absorb and use water. When you drink large amounts of water with a near-zero TDS, like Aquafina, your body gets the fluid but not the necessary electrolytes to properly process it. This can disrupt the cellular fluid balance, leading to a feeling of being less quenched and sometimes even more thirsty as the body signals for more minerals to compensate. Think of it like trying to build a wall with just bricks but no mortar; the water (bricks) is there, but without electrolytes (mortar), it can’t be used efficiently.

Comparison Table: Aquafina vs. Spring Water


Feature	Aquafina (Purified Water)	Natural Spring Water
Source	Public water sources, purified via advanced systems.	Natural underground formation, collected at the source.
Purification	Multi-stage process including reverse osmosis and ozonation.	Minimal processing to ensure safety, preserves natural mineral content.
Mineral Content (TDS)	Very low, often single-digit parts per million (ppm).	Varies by source, generally higher than purified water (>250ppm for mineral water).
Taste	Often described as neutral or “flat” due to lack of minerals.	Distinct flavor profile influenced by natural minerals present.
Hydration Effect	Hydrates, but may leave a feeling of lingering thirst due to low electrolyte levels.	Hydrates effectively, with natural electrolytes aiding cellular absorption.
Cost	Typically priced at a lower-to-mid range for bottled water.	Can range from mid- to high-end depending on the brand and source.

Other Factors Contributing to Persistent Thirst

While the low mineral content of purified water can be a factor, persistent thirst might be a symptom of broader lifestyle and health issues. Understanding these factors is crucial for effective hydration.

Common Causes of Dehydration and Thirst:

Dietary Habits: A diet high in salty or spicy foods can increase your body’s sodium levels, requiring more fluid to balance them. Similarly, excessive caffeine or alcohol consumption can have a diuretic effect, causing increased urination and fluid loss.
Physical Activity and Environment: Strenuous exercise, especially in hot or humid conditions, leads to significant fluid and electrolyte loss through sweat. High altitudes can also contribute to dehydration.
Underlying Health Conditions: Persistent, unquenchable thirst (polydipsia) can be a symptom of more serious medical conditions such as diabetes mellitus or diabetes insipidus. If accompanied by symptoms like frequent urination, fatigue, or unexplained weight loss, it warrants a doctor's visit.
Certain Medications: Some prescription drugs, including diuretics and antidepressants, can cause dry mouth and increase feelings of thirst as a side effect.

What can you do to hydrate more effectively?

To counteract the effects of drinking highly purified water, there are several simple and effective strategies. First, consider remineralizing your water by adding a small amount of electrolyte drops or a pinch of pink Himalayan sea salt to your glass. This helps your body absorb the fluid more efficiently. Additionally, incorporating a variety of hydrating foods into your diet is beneficial. Many fruits and vegetables like watermelon, cucumbers, and spinach have high water content and come with a bonus of natural electrolytes. For those who exercise intensely, a balanced electrolyte beverage may be more effective than plain water alone. Finally, paying attention to your overall fluid intake from multiple sources throughout the day, rather than relying solely on one type of bottled water, can make a significant difference in how hydrated you feel. For further information on general hydration, visit the Mayo Clinic website.

Conclusion

While Aquafina's reverse osmosis purification delivers incredibly pure water, it lacks the essential minerals and electrolytes necessary for optimal cellular hydration, which can explain the feeling of persistent thirst in some individuals. This, combined with other factors like diet and health, contributes to the overall puzzle. For more effective hydration, consider adding minerals back to your water, consuming water-rich foods, and listening to your body's signals for a more balanced approach to drinking water.

Frequently Asked Questions

No, Aquafina water is not bad for you. It is highly purified and safe to drink. However, its low mineral content can sometimes leave some individuals feeling less quenched than mineral-rich spring or tap water.

Highly purified water, especially through processes like reverse osmosis, removes electrolytes. For some people, this can disrupt the body's natural fluid balance and lead to a feeling of lingering thirst, as the body seeks minerals to aid in absorption.

Electrolytes are minerals like sodium, potassium, and magnesium that help regulate fluid balance in your cells and throughout your body. Without them, water absorption can be less efficient, leaving you feeling dehydrated despite drinking water.

Purified water, like Aquafina, is treated to remove almost all dissolved solids and contaminants. Spring water is sourced from a natural underground formation and contains naturally occurring minerals and electrolytes.

You can add minerals back to purified water by using mineral drops, which are available at most health food stores. Alternatively, adding a pinch of a mineral-rich salt like Himalayan pink salt can also help.

Yes, a diet high in sodium, from salty or processed foods, can increase thirst. The body needs more fluid to process the excess sodium and maintain proper balance.

If you experience persistent, excessive thirst (polydipsia) accompanied by other symptoms like frequent urination, unexplained weight loss, fatigue, or blurry vision, it is advisable to consult a healthcare provider to rule out conditions like diabetes.