Though mayonnaise is becoming a fad lice treatment, there’s not much scientific proof that it works.

Lice are small, wingless parasites that live on the scalp, feasting on blood. They’re highly contagious and spread by laying several eggs per day and living up to a month at a time.

There are several effective treatment options for lice. Home remedies and over-the-counter (OTC) products can work in some cases, but not always. This includes mayonnaise.

Mayonnaise is a combination of egg yolks, vinegar, and vegetable oils. These ingredients aren’t designed to kill lice and their eggs (called nits) like prescription and OTC formulas. But many people are using mayonnaise in an effort to find a safe, more natural lice remedy.

To effectively get rid of lice, you need to get rid of both the parasites and the nits. The theory behind mayonnaise is that it will help “suffocate” the lice so that they die off.

However, there’s no solid proof that this method works. If anything, you might see reduced activity in your scalp temporarily, but the lice will likely come back.

Another drawback to using mayonnaise for lice is that it won’t catch and suffocate all the parasites as effectively as other methods. Furthermore, mayonnaise has no effect on nits. This means that the nits can hatch in the near future, and you’ll have to start your lice treatment all over again.

The biggest risk to using mayonnaise for hair lice is that there’s no solid guarantee that this method will actually work. You could then put yourself and others at risk of getting a lice infestation.

If you have naturally oily hair and scalp, you might find that the mayonnaise adds extra oil you really don’t need. This in turn could cause breakouts around your hairline, face, and neck, especially if you’re already prone to acne.

Another side effect is the possible unpleasant smell, especially if you leave the mayonnaise in for too long. Using mayonnaise with egg yolks can also start smelling rotten if you don’t get the product out of your hair completely after use.

Since mayonnaise contains egg yolks, it can also trigger an allergic reaction in people who have an egg allergy.

While mayonnaise isn’t recommended as a treatment for lice, there are some smothering treatments that work well.

The key is to comb the hair with a fine-toothed comb after coating the hair. Many experts believe that smothering treatments only stun the lice, making them slower and easier to catch with the comb.

If you want to try the smothering technique, use olive oil or almond oil instead of mayonnaise. They aren’t as messy and are easier to clean out of your hair. You’ll also need a lice comb.

Use these steps:

  1. Get the hair completely wet, squeezing out any excess water.
  2. Coat the hair with olive or almond oil. Or, you can try coating the lice comb instead of the hair, reapplying the oil as needed. Try both methods and use whichever works best for you.
  3. Use a hair clip to separate the hair into a small section. Then run a lice comb through each section of hair, slowly moving across the whole scalp. Rinse out the comb often under hot water.
  4. Once you’ve combed all of the hair, wash the hair with shampoo, rinse, and repeat. Then dry the hair.
  5. Wash any towels you used and clean the comb thoroughly. Soak the comb in a 10 percent bleach solution for 30 minutes, and then rinse it well.
  6. Follow these steps every day for one week. Then, for two more weeks, check by combing every night to make sure the lice are gone.

In addition to the smothering technique, there are several other lice treatments you can try. Here are some of the most common.

Hair dye

Certain types of hair dye contain potential lice-killing ingredients. These include hydrogen peroxide and ammonia. The downside to this remedy is that it’s not guaranteed to kill nits, and it’s also not ideal for young children.

OTC lice kits

Over-the-counter lice elimination kits contain ingredients that are specifically formulated to kill lice. These include permethrin and pyrethrin, which you can find in lice shampoos.

You use these products by applying them to the scalp, leaving them in for several minutes, and then rinsing them out. You will then need to use a lice comb to remove any leftover parasites and their nits.

These products are used for several days until the scalp is completely lice-free.

Coconut oil

Like mayonnaise, coconut oil has a rich and thick consistency that’s sometimes used as means of suffocating lice and their nits.

However, aside from getting smooth hair out of this treatment, there’s little to no evidence that coconut oil will get rid of lice for good.

Essential oils

Essential oils are on the rise as alternative treatments to drugs and chemicals. Some essential oils that have antiparasitic and antifungal properties may also offer lice relief, but more studies are needed.

Among the possible oils you can use include tea tree oil, eucalyptus oil, and peppermint oil.

However, just because essential oils are alternative remedies doesn’t mean they’re not without risk. You will need to dilute your oils using a carrier oil beforehand to avoid contact dermatitis on your scalp.

When OTC products or home remedies fail to clear up your lice problem, it’s time to see a doctor. They can recommend prescription-strength treatments, such as benzyl alcohol or malathion.

If these methods fail to work, a last-resort treatment is lindane shampoo. This is an extremely powerful medication that can cause side effects. It’s not recommended for use in pregnant or nursing women, older adults, people with a history of seizures, people with skin conditions, and young children.

Besides making your hair feel messy and oily, mayonnaise is unlikely to treat head lice. If you’re dealing with a parasitic infection, you’re better off using OTC medication or seeing a doctor.