Nasal saline is a simple mixture of salt and water used to rinse, moisturize, or clear out the nasal passages. The standard version, called normal saline, has a salt concentration of 0.9%, which matches the salt level of your body’s own fluids. It’s available as a store-bought spray or rinse, or you can make it at home with a few kitchen ingredients. People use it for everything from clearing out congestion during a cold to managing chronic sinus problems and seasonal allergies.
What’s in It
At its most basic, nasal saline is just salt dissolved in water. The 0.9% concentration is called “isotonic” because it matches the saltiness of your body’s cells, so it doesn’t sting or irritate the lining of your nose. Some formulations also include a small amount of baking soda, which acts as a buffer to bring the solution closer to your body’s natural pH and makes it more comfortable to use.
Commercial nasal saline sprays often contain a preservative called benzalkonium chloride to prevent bacterial growth in the bottle. This preservative is found in more than 200 nasal products on the market. However, it comes with a tradeoff: lab studies show it can slow or stop the movement of the tiny hair-like structures (cilia) that sweep mucus through your nose, and the European Medicines Agency notes it may cause irritation or swelling inside the nose with long-term use. If you use saline spray regularly, preservative-free versions are worth seeking out.
How It Works in Your Nose
Your nasal passages are lined with a thin layer of mucus that traps dust, allergens, and germs. Underneath that mucus, millions of microscopic cilia beat in coordinated waves to push everything toward the back of your throat, where it’s swallowed and destroyed by stomach acid. When you’re sick or dealing with allergies, mucus thickens and the system gets overwhelmed. Nasal saline helps by physically flushing out that thickened mucus along with the irritants trapped in it.
An isotonic solution does this gently, without disrupting the cilia. Higher-concentration “hypertonic” saline (typically around 2 to 3% salt) works a bit differently. Because it’s saltier than your body’s fluids, it pulls water out of swollen nasal tissue through osmosis, reducing congestion and thinning out sticky mucus. Research comparing the two after sinus surgery found that hypertonic saline produced better results for mucosal swelling, crusting, nasal obstruction, and facial pain. The downside is that concentrations above 3% can actually damage the nasal lining and stop cilia from moving, so more is not better here.
Isotonic vs. Hypertonic Saline
Isotonic (0.9%) is the gentler, everyday option. It moisturizes dry nasal passages, loosens mild congestion, and rinses away allergens without side effects. Most people find it comfortable enough to use daily.
Hypertonic (usually 2 to 3%) is the stronger decongestant. It actively draws fluid out of swollen tissue and breaks up thick mucus. It’s particularly useful after sinus surgery or during a stubborn sinus infection, but it can cause a brief burning sensation. If you find it uncomfortable, diluting the solution slightly usually helps. Concentrations of 7% or higher have been shown to stop cilia from beating within minutes, and a 14.4% solution causes irreversible damage, so there’s no reason to go above 3% for nasal use.
Common Uses
Nasal saline is one of the few remedies that helps across a wide range of nasal and sinus problems. It’s commonly used for relief during colds, flu, and COVID-19, where it helps clear congestion and wash viral particles from the nasal lining. For seasonal allergies, rinsing with saline after time outdoors physically removes pollen before it can trigger a prolonged immune response. Some people without any active symptoms rinse a few times a week as a preventive measure to reduce the frequency of sinus infections or allergy flare-ups.
It’s also a staple for chronic sinusitis, where regular irrigation helps keep the sinuses draining properly. For babies and young children who can’t blow their noses, a few drops of saline in each nostril loosens mucus so it can be suctioned out or sneezed away.
How to Make It at Home
The recipe recommended by the American Academy of Allergy, Asthma and Immunology is straightforward. Mix 3 teaspoons of non-iodized salt (pickling or canning salt works well) with 1 teaspoon of baking soda and store the dry mixture in an airtight container. When you’re ready to use it, dissolve 1 teaspoon of the mixture in 8 ounces (1 cup) of lukewarm water. For children, use half a teaspoon of the dry mix in 4 ounces of water. If the solution stings, use a little less of the dry mixture next time.
Avoid iodized table salt or salt with anti-caking agents, both of which can irritate the nasal lining. The baking soda isn’t strictly necessary, but it buffers the solution so it feels less harsh.
Water Safety Is Critical
The single most important safety rule for nasal irrigation is using the right water. Tap water is safe to drink because stomach acid kills most pathogens, but your nasal passages have no such defense. Tap water can harbor amoebas, specifically Naegleria fowleri and Acanthamoeba, that are harmless if swallowed but can cause a nearly always fatal brain infection if they travel up through the nose.
The CDC recommends three safe options: store-bought water labeled “distilled” or “sterile,” tap water that has been boiled at a rolling boil for at least 1 minute (3 minutes at elevations above 6,500 feet) and then cooled, or water passed through a filter labeled to remove organisms 1 micron or smaller. Never use water straight from the tap, a garden hose, or a shower head for any nasal rinse.
Using Saline for Babies and Children
Saline drops are one of the safest options for clearing a stuffy nose in infants who are too young for decongestant medications. Lay your baby flat on their back or tilt their head back slightly, place two to three drops of saline in each nostril, and wait a few minutes for the solution to loosen the mucus. Wrapping a baby snugly in a light blanket can help keep their arms still during the process. After a couple of minutes, you can use a bulb syringe to gently suction out the loosened mucus.
Many saline products are marketed for adults and may carry labels stating they haven’t been tested in children under 12. This is usually a licensing issue rather than a safety concern, since the product is just salt water. Preservative-free saline drops designed specifically for infants are widely available and avoid any question about additives.
How Often You Can Use It
Saline nasal irrigation is safe for frequent use. General guidance from Oregon Health and Science University suggests using up to 8 ounces per nostril once or twice a day. During an active cold or allergy season, twice daily is common. Some people maintain a once-daily or every-other-day routine year-round for prevention. There’s no evidence that regular isotonic saline use causes rebound congestion or dependency, which makes it fundamentally different from medicated decongestant sprays that lose effectiveness over time.
Between uses, rinse your neti pot, squeeze bottle, or irrigation device with safe water and let it air dry completely. Bacteria and mold can grow in damp irrigation equipment, which defeats the purpose of a clean rinse.