Most people searching for how to remove fluoride from drinking water fall into one of two groups.

The first group has well water with naturally occurring fluoride above the EPA maximum contaminant level of 4.0 mg/L. Long-term exposure above that level is associated with skeletal fluorosis, a condition that affects bone density and joint health. This is a real health risk, and treatment is appropriate.

The second group is on municipal water and has made a personal decision to reduce their fluoride intake. That’s a valid choice to make for your own household. This page doesn’t take a position on municipal fluoridation policy. It just covers what works.

Either way, the treatment options are the same.

What Doesn’t Remove Fluoride

Start here, because this is where most people waste money.

Standard activated carbon filters do not remove fluoride. That includes Brita pitchers, most refrigerator filters, and basic faucet attachments. Activated carbon is excellent for chlorine, chloramines, and some organic compounds. It does very little for fluoride. If you’ve been relying on a standard pitcher filter for fluoride reduction, it hasn’t been working.

Boiling does not remove fluoride. It makes it slightly worse. As water evaporates during boiling, the fluoride that was dissolved in it stays behind. The resulting water has a marginally higher fluoride concentration. This is one of the most persistent misconceptions in home water treatment.

Water softeners do not remove fluoride. Softeners work through ion exchange to reduce calcium and magnesium hardness. Fluoride ions pass right through the resin unchanged. A softener treats hardness, not fluoride.

Sediment filters do not remove fluoride. They filter particles. Fluoride is dissolved in solution, not suspended as a particle. No particle filter touches it.

What Actually Works

Reverse Osmosis (The Most Practical Option)

RO systems push water through a semi-permeable membrane with pores around 0.0001 microns. At that scale, fluoride ions are physically rejected by the membrane.

NSF/ANSI 58 is the certification standard for reverse osmosis drinking water systems. Certified systems are tested against a defined list of contaminants. Fluoride is on that list, but not all NSF 58 certified systems specifically test for it. Before buying, check the product’s NSF certificate to confirm fluoride is listed as a tested contaminant. The NSF product database at nsf.org lets you look up any certified system by model number.

Systems that do carry fluoride reduction data from NSF testing typically show 85-92% reduction, though your actual results will vary based on your source water chemistry, water pressure, and the age of the membrane.

For most households, an under-sink RO system is the right call. It installs below the kitchen sink, connects to a dedicated faucet, and handles your drinking and cooking water. No whole-house system needed. Most households drink and cook with only a small fraction of total water use.

If you rent or can’t drill, a countertop RO unit connects directly to your existing faucet. Performance is comparable. Flow rate may be slower.

One practical note on RO: the systems do waste some water. A typical ratio is one gallon rejected for every three gallons produced, though newer tankless systems are improving on that. It’s not zero-waste treatment. It’s a worthwhile trade-off for most people.

Activated Alumina

Activated alumina is a porous aluminum oxide media specifically designed to adsorb fluoride. It’s used in some under-sink systems and standalone fluoride reduction filters.

Performance is pH-dependent. It works best at a pH below 7.0 and loses effectiveness above 8.5. If your water is alkaline, activated alumina underperforms.

A handful of pitcher-style systems use activated alumina to claim fluoride removal. Some of them have real data behind those claims. Look for specific NSF certification or published third-party test results before buying. Marketing language about fluoride removal isn’t the same as certified performance data.

Activated alumina media requires periodic replacement. As the adsorption sites fill, capacity drops.

Bone Char Carbon

Bone char is made from calcined animal bones. The resulting material specifically adsorbs fluoride, among other contaminants. It’s been used in water treatment for over a century.

It’s less common in consumer products than RO or activated alumina, but some specialty filters use it. Effectiveness varies with pH and the presence of competing ions like sulfate and chloride, which compete for the same adsorption sites.

It’s not suitable for everyone, and it’s not widely available in mainstream retail. Worth knowing exists, but not the starting point for most people.

Distillation

Distillation removes essentially everything from water, including fluoride. Water is boiled to steam, the steam is collected and condensed, and dissolved contaminants stay behind in the boiling chamber.

The practical problem is volume. A countertop distiller produces about one gallon of water every four to six hours and uses significant electricity to do it. For a household that needs filtered water for drinking, cooking, and general use, it’s a slow and expensive approach per gallon.

If you already have a distiller for another reason, it handles fluoride. But buying a distiller specifically for fluoride reduction when an RO system costs less and produces water faster doesn’t make much sense for most households.

Verify After Installation

After installing any fluoride-reduction system, test your water. Don’t assume the system is working because the marketing says it should.

Home fluoride test strips give a rough reading and cost around $10-15. For more precise numbers, a certified mail-in lab test is the better option. Test 2-3 weeks after installation to let the system stabilize, then compare the result against your pre-treatment fluoride level.

This matters especially for source water with naturally high fluoride. If your well water came in at 5.5 mg/L and the filter is only getting it down to 3.5 mg/L, you’re still below the EPA MCL but you should know that. And if performance is declining month to month, you need to know that too.

Well water fluoride levels can also vary seasonally. Testing once a year is reasonable ongoing maintenance if you’re on a private well.

Certification to Look For

For any filter claiming fluoride removal, the certification to ask about is NSF/ANSI 58 for RO systems. For other filter types, ask specifically whether fluoride reduction data exists and whether it comes from NSF testing or independent lab testing.

Many filters are sold with fluoride removal claims that have no third-party data behind them. That doesn’t mean they don’t work. It means you can’t verify they work.

One pitcher filter that has published fluoride reduction data is Clearly Filtered. It’s one of the few pitcher-style options with specific documentation for fluoride, among other contaminants. It costs more than a standard Brita, but it actually does what it says for fluoride.

The Recommendation

For well water testing above 4.0 mg/L: get an NSF/ANSI 58 certified under-sink RO system with fluoride listed on the certificate. That’s the most reliable path to consistent fluoride reduction. Confirm it’s working with a post-installation test.

For municipal water: if you’ve decided you want to reduce fluoride, the same RO recommendation applies. It’s the most documented option available to homeowners. A quality countertop RO works if you rent.

Either way, test your source water first. Fluoride concentration in your specific water supply affects which system performs best and gives you a baseline to measure against.

For contaminant background, see the fluoride contaminant profile.