How to Unclog Your Drain with Hydrogen Peroxide & Baking Soda

Few things in modern life are as annoying, unpleasant, and time-consuming as a clogged drain. Whether it be in your toilet, shower, tub, bathroom, or kitchen sink, odds are you belong to the majority who want to unclog that drain as soon as possible, perhaps even by any means necessary. 

If you found this article while searching for quick and easy ways to unclog your drain, you’re in luck. Below you’ll find everything you need to know to unclog your drain using hydrogen peroxide. 

Unclog Your Drain with Hydrogen Peroxide

There are many chemicals you can use to unclog your drain. The problem is that some chemicals may be too harsh and cause damage to your pipes or seals. A lot of these chemicals are also bad for the environment so you may think twice before flushing them down your drain and into the water system.

This is why hydrogen peroxide is one of the best choices for unclogging your drain. 

Why Hydrogen Peroxide is a Great Unclogger 

Hydrogen peroxide is a clear, pale bluish chemical related to, but slightly denser than, water. Unlike solvents, hydrogen peroxide is biodegradable while still being effective due to its oxidative trait. Because of its reactive and unstable nature, hydrogen peroxide generates hydroxyl radicals that oxidate and degrade matter while destroying bacteria, fungi, viruses, and pathogens. 

What Hydrogen Peroxide Concentration to Use 

Hydrogen peroxide comes in a variety of concentrations. Each formula performs a different function making them more suitable for specific purposes. 

Hydrogen Peroxide

For unclogging your drain, you can use 3% hydrogen peroxide which you commonly get in those brown bottles at pharmacies. 

Using Hydrogen Peroxide to Unclog Your Drain 

Now that we've discussed the details, it's for the main event: using hydrogen peroxide to unclog your drain.

First, you need to remove any physical gunk and debris blocking your drain. This can either be bits of food, hair, or whatever. You can remove these from hard-to-reach places with a plastic hair snake (available at hardware stores). 

Cleaning out drains with H2O2

Next, boil one-half to a gallon of water then let it cool a bit to keep it from damaging any pipes or seals (5 minutes will do). Then pour the hot water down your drain. Wait another 5 minutes then turn on your cold water tap which should solidify any remaining grease. 

Now it's time to pour ½ to 1 cup of baking soda down the drain. Let it work its magic for at least ten minutes then pour 1 cup of hydrogen peroxide. 

It's this mixture of baking soda and hydrogen peroxide that breaks down whatever waste and gunk are clogging your drain. If you see some foaming then you know it's working. Don't use your drain for several hours after this step. 

Make sure to keep the rest of the baking soda and hydrogen peroxide for other uses. 

After several hours have passed, boil some hot water again and wait 5 minutes before pouring it down your drain one last time to rinse away whatever is left of the blockage. Your drain should function better or normally at this point. 

You can repeat the process if you wish. 

When to Use a Hydrogen Peroxide Cleanse 

It's important to note that this method doesn't always work for all types of blockages. There are certain blockages where professional services are simply the only option. 

Here are some drain blockages that you can take care of yourself:


A P-trap is a U-shaped bend in your sink's drain pipe that contains water. It uses that water to seal and prevent sewer gases from drifting into your water systems and directs these gases into the ventilation system, which directs them outdoors.

A P-trap can dry up because of a leak, blockage, or simply not being used for a long time. This causes an overwhelming stench to waft up from the sewers.

Cleaning P-traps with H2O2

You can use the hydrogen peroxide rinse we discussed above to fix your blocked P-trap.

Sewer Gas Ventilation Systems

Sewer vent systems guide sewer gas out of your home. Ideally, you'd want to keep these vents clog-free to prevent your home from reeking from the deep dark sewers. Unfortunately, dead leaves, animal neats, and debris often clog these vents which prevents them from functioning optimally. 

You can handle clogged vents yourself if the blockage is reachable. Unfortunately, you won't be able to fix it with a hydrogen peroxide cleanse if it's deeper down or is interlaced with wiring. In that case, you'll need to contact your local plumbing services for help. 

Water Heaters

Water heaters provide precious hot water for us living in colder climates. The problem is that these water heaters make good homes for bacteria and even provide them with sulfur. This combination of bacteria and sulfur can do a number on your heater's metallic components which then leaves that rotten smell that you can't seem to pinpoint. 

Water Heaters

In this case, the problem is often your heater's anode which is usually made up of magnesium and aluminum. Bacteria love making their homes in magnesium and aluminum-based so your first solution may be to replace yours with a zinc and aluminum one. Of course, you can also use the hydrogen peroxide cleanse to disinfect and sterilize your anode. 

Preventing Future Clogs

While you've now learned the hydrogen peroxide cleanse method to cure clogged drains, it's always better to prevent your drains from getting clogged in the first place. 

You can pour 1 cup of hydrogen peroxide down your drain once every 2 weeks as a preventative measure. 

You can also use the hydrogen peroxide cleanse on your drains the moment you notice your drain slow down. 

Maybe invest in better sink stoppers to keep objects from going down and clogging your sink. 

Precautions With Hydrogen Peroxide 

Make sure to store your leftover hydrogen peroxide in a cool dry place, away from direct sunlight, heat, or sources of fire. Keep it in a place away from children and pets.

3% hydrogen peroxide can last several years as long as it's sealed. Once unsealed, you have just a few months until it fully decomposes. 

Make sure to dispose of hydrogen peroxide properly. 3% hydrogen peroxide is safe enough to pour down your drain. 

If you've diluted food grade 35% hydrogen peroxide to unclog your drain, you'll need to dispose of any leftover 35% hydrogen peroxide according to the manufacturer's instructions.

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