Making mouthwash at home takes a few simple ingredients and about two minutes. The most basic version requires nothing more than baking soda and water, while slightly more advanced recipes add salt, hydrogen peroxide, or essential oils for extra antimicrobial action. Here’s how to make each type and use it effectively.
Baking Soda Mouthwash
This is the simplest and most widely recommended homemade rinse. Mix 1/4 teaspoon of baking soda into 1 cup (250 mL) of tap water and stir until it fully dissolves. That’s it.
Baking soda works differently than commercial mouthwashes. It doesn’t kill bacteria directly. Instead, it raises the pH inside your mouth, making the environment less acidic and less hospitable to the bacteria that cause cavities. A study published in the National Journal of Maxillofacial Surgery found that a sodium bicarbonate rinse significantly increased salivary pH after use. The alkaline shift reduces the virulence of cavity-causing bacteria like Streptococcus mutans, and the baking soda itself acts as a gentle cleanser by dissolving mucus and loosening debris from your teeth and gums.
Make a fresh batch each day. Baking soda dissolved in plain water has no preservative, so it won’t stay stable for long.
Salt Water Rinse
A warm salt water rinse is especially useful after dental procedures, mouth sores, or a sore throat. Dissolve 1/2 teaspoon of table salt into 1 cup of warm water. The warmth helps the salt dissolve faster and feels soothing on irritated tissue.
Salt draws moisture out of swollen tissue through osmosis, which can reduce inflammation and help minor wounds in the mouth heal faster. It also creates a temporarily inhospitable environment for bacteria. You can combine salt and baking soda in the same rinse (1/4 teaspoon baking soda plus 1/2 teaspoon salt in 1 cup of warm water) if you want both the pH-raising and anti-inflammatory effects at once.
Hydrogen Peroxide Rinse
Hydrogen peroxide adds genuine germ-killing power to a homemade mouthwash. The key is getting the concentration right. Most clinical studies on hydrogen peroxide mouth rinses use a 1.5% solution. The standard brown bottle you buy at the drugstore is 3%, so you need to dilute it by mixing equal parts peroxide and water. That brings you to roughly 1.5%, the concentration that’s been studied most for oral use.
For a single rinse, combine 1 tablespoon of 3% hydrogen peroxide with 1 tablespoon of water. Swish it around your mouth, then spit it out completely. Do not swallow it. You can use this once or twice a day. If it causes any stinging or irritation, switch to a weaker mix (one part peroxide to two parts water) or stop using it.
Hydrogen peroxide breaks down quickly once mixed, so prepare only what you need for each rinse rather than storing a batch.
Adding Essential Oils
Peppermint oil gives your rinse a fresh taste and mild cooling sensation. Tea tree oil has some antibacterial properties. But essential oils are potent and need very careful handling in anything that goes in your mouth.
The important rule: use no more than 1 to 2 drops per cup of water. Essential oils don’t dissolve in water on their own, so you’ll need to add 1/2 teaspoon of baking soda or a pinch of salt first, stir the oil drops into that dry ingredient, then add the water and mix well. This helps disperse the oil more evenly. “Hot” oils like cinnamon and clove are especially irritating at higher concentrations and should be avoided entirely in mouth rinses unless you have experience working with them. Peppermint is the safest and most practical choice for flavor.
Skip essential oils altogether for children under ten.
A Simple All-Purpose Recipe
If you want one rinse that covers multiple bases, this combination works well:
- Water: 1 cup (250 mL), warm
- Baking soda: 1/4 teaspoon
- Salt: 1/4 teaspoon
- Peppermint oil: 1 drop (optional, for flavor)
Stir until the baking soda and salt dissolve. Use within a few hours.
How to Use Your Rinse
Take a comfortable sip, then swish it around your entire mouth for 30 to 60 seconds. Most people cut this short. One study found that 84.5% of regular mouthwash users rinse for less than the manufacturer-recommended 30 to 60 seconds. Set a mental timer or count slowly to 30 at minimum. If you’re targeting a sore throat, tilt your head back and gargle for part of that time.
Spit the rinse out completely. Rinse once or twice a day, ideally after brushing and flossing. Using mouthwash before brushing can loosen debris, but using it after gives the active ingredients more contact time with cleaner tooth surfaces.
What Homemade Mouthwash Can and Can’t Do
A baking soda or salt rinse is excellent for freshening breath, soothing irritated gums, and creating a less acidic oral environment. It’s a good daily supplement to brushing and flossing. Hydrogen peroxide adds measurable antibacterial action that can help with mild gingivitis.
What homemade mouthwash won’t do is replace the specific active ingredients in prescription or clinical-strength rinses designed for gum disease, dry mouth, or post-surgical care. It also won’t reverse cavities or treat infections. Think of it as a useful, inexpensive layer of daily oral hygiene, not a treatment for existing problems.
Storage and Shelf Life
Homemade mouthwash contains no preservatives, so bacteria can grow in it if it sits around. The safest approach is to mix a fresh batch each day. If you want to prepare a larger quantity, store it in a clean, sealed glass jar and use it within two to three days. Hydrogen peroxide rinses should always be mixed fresh, since the peroxide loses potency rapidly once diluted.