How Does a Bleach Pregnancy Test Work?

Standard pregnancy tests work by measuring the presence of hCG. The bleach pregnancy test does too, making it an effective homemade pregnancy test.


Don’t have time to stop at the drug store for a pregnancy test? Or maybe it’s nearing midnight and your curiosity is getting the best of you. You just need to know: are you pregnant or not? If you have a bottle of household bleach in the home, you can soon find out.

While not completely conclusive, the bleach pregnancy test is a popular method of determining pregnancy at home. The test involves the use of bleach, a common household chemical typically used to clean clothes.

Homemade pregnancy tests may be less reliable than standard urine and blood tests but they work in a similar way. Like all urine-based pregnancy tests, the bleach pregnancy test determines whether or not you’re pregnant by detecting the presence of human chorionic gonadotropin (hCG), a hormone produced during pregnancy.

What Experts Have to Say

Little research has been performed to prove the effectiveness of the bleach pregnancy test. However, most experts agree that the results are not definitive.

“As there is no scientific data available for bleach pregnancy test and due to lack of standardization, it not a reliable one,” says Dr. Jimesh H. Mavani, General Practitioner in Obstetrics and Gynecology. “Yes, it is true that bleach can react with hCG (human chorionic gonadotropin). But, without standardization about the concentration and quantity of bleach to be used, the test can be both positive and false negative. The accuracy can vary from 20% to 80%.”

Bleach isn’t the only ingredient used in homemade pregnancy tests. Across the internet you’ll find people claiming the same thing about sugar, baking soda, and even toothpaste. While there’s no harm in trying these methods, don’t expect conclusive results.

“Regardless if the toothpaste foams or not, you still won’t know if you’re pregnant – this does, however, sound like a great way to ruin a perfectly good dish,” says chief OB/GYN resident Caitlin McAllister at MedStar Georgetown University Hospital.

“That being said, it’s kind of understandable why some people might think this works, because doctors use urine to test whether or not a person is pregnant. But it’s not as simple as peeing on random household items and seeing what happens.”

How to Perform the Bleach Pregnancy Test

Household bleach is highly reactive, meaning it will froth, foam, bubble, steam, or undergo other visible changes when it comes into contact with different substances. One such substance that causes a visible change is hCG, the hormone created by the placenta during pregnancy.

Creating a homemade bleach pregnancy test is simple. The only thing you will need to perform the test is regular household bleach. If you do not have bleach on hand, you can purchase it in most big box or grocery stores, as well as most dollar stores.

Don’t worry about buying an expensive brand of bleach. The cheaper, generic or discounted varieties work just as well as the expensive brands. Avoid bleach that has added dyes or artificial scents. These added ingredients can interfere with the result of the test.

Follow these instructions to perform the bleach pregnancy test at home:

  1. Pour about eight ounces (1 cup) of bleach in a clean, sterile cup or container. You can sterilize most containers in a pot of boiling water for five minutes.
  2. Urinate into another clean, sterilized container. Just a small amount of urine is needed to see a reaction.
  3. Pour the urine into the container of bleach. Do so slowly to prevent the bleach from splashing on you.
  4. Look for a reaction. If you are pregnant, the bleach should start to fizz and foam within seconds, similar to how beer foams when you pour it into a glass. If the bleach does not fizz or foam at all, you are likely not pregnant or you tested too early.

How Accurate Is the Bleach Pregnancy Test?

So you’ve taken the bleach pregnancy test and saw it foam and fizz. Or maybe you took it and nothing happened. You may be wondering how accurate the results really are. From a scientific standpoint, the results are fairly accurate.

If you saw a strong reaction when performing the bleach pregnancy test, there is a high chance that you’re pregnant.

However, that does not necessarily mean that you are not pregnant if you don’t see a reaction. As the test detects the presence of hCG to determine pregnancy, not having a sufficient level of the hormone in your system can result in a negative result.

This can happen if you take the test too early in your pregnancy. Pregnancy tests are most reliable from the first day of your missed period, according to National Health Service, although some tests can be used as early as four or five days before your period is due.

Other factors can also interfere with the results of a home pregnancy test. During early pregnancy, you may only get a result by using your morning’s first urine. This is because your urine can become diluted as you begin to take in fluids. If you take certain medications that produce a diuretic effect, your urine may also not be as concentrated.

While it can be fun to try, know that the bleach pregnancy test is not definite. If you suspect that you may be pregnant, purchase a store-bought pregnancy test or consult with your doctor.


Brandy Dishaw

Brandy is a content specialist and proud mother of two children. She enjoys writing engaging content on parenting, children’s health, and educational topics, and has been published on websites like Modern Mom, Yahoo! Shine, and With more than a decade of experience as a writer and mom, she combines research and personal experience to provide her audience with insight to the world of parenting.

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