Overview

Soybean oil comes from soybeans (Glycine max). It is commonly used as a cooking oil and is also added to skin care and insect repellent products. Although soybean oil seems to be well tolerated, the benefits of applying it to the skin for any purpose are unclear. If you have a soy allergy, speak with your health care provider before using soybean oil.

Uses

What is soybean oil used for?

Soybean oil is used as a cooking oil. It is also added to some skin care products and insect repellents, although its benefits are not well defined.

Note: Soybean oil is generally recognized as safe (GRAS) by the FDA for use in foods and as a cooking oil. Learn more about GRAS status here. As a skin care ingredient, the FDA has not reviewed soybean oil for safety and effectiveness. Learn more about cosmetics here.

How does soybean oil work (mechanism of action)?

Soybean oil comes from the beans of the soy plant. Soybeans are commonly used to make various food products, including tofu, miso, soy sauce, soy milk, and soy nuts. The oil made from soybeans is often used as a cooking oil, insect repellent, and skin care ingredient.

As with other seed oils, soybean oil contains unsaturated fats, including linoleic acid (an omega-6 fatty acid) and oleic acid (an omega-9 fatty acid). Most research shows that cooking with unsaturated fats can help lower cholesterol levels, as long as they replace saturated fats. Lower cholesterol levels may help reduce the risk of heart disease and serious health problems, such as a heart attack or stroke. It is not clear if any specific seed oil is better for heart health than other seed oils.

As an ingredient in skin care products, soybean oil is used to hydrate the skin, act as an antioxidant, and help reduce redness and swelling (inflammation). However, there is very little research to support these claims. The effects of soybean oil on the skin are not well understood or defined.

When insects come into contact with soybean oil, it may cause them to suffocate. As a result, some “natural” insect repellents contain soybean oil, especially those that are meant to be used against mosquitoes and black flies. However, the actual effects of soybean oil against any insects are unclear. Most experts recommend using soybean oil in combination with insect repellents that are known to work well against these insects.

Natural substances like soybean oil contain many different chemicals. The amounts of each chemical in a specific soybean oil product may vary. Some, none, or all of these chemicals may have effects on the body. These effects may change depending on how much of each chemical is found in the product you are using.

How should I store soybean oil?

You should store soybean oil according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.

Side Effects

What are the most common side effects of soybean oil?

Soybean oil seems to be well tolerated. Tell your health care provider if you have any side effects that bother you.

There may be side effects of soybean oil that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of soybean oil?

While less common, the most serious side effects of soybean oil are described below, along with what to do if they happen.

Severe Allergic Reactions. Soybean oil may cause allergic reactions, which can be serious. Stop using soybean oil and get help right away if you have any of the following symptoms of a serious allergic reaction.

• Breathing problems or wheezing
• Racing heart
• Fever or general ill feeling
• Swollen lymph nodes
• Swelling of the face, lips, mouth, tongue, or throat
• Trouble swallowing or throat tightness
• Itching or skin rash
• Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
• Nausea or vomiting
• Dizziness, feeling lightheaded, or fainting
• Stomach cramps
• Joint pain

Precautions

Who should not use soybean oil?

Allergies to Ingredients. People who are allergic to any of the following should not use soybean oil.

• Soybean oil
• Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific soybean oil products they stock.

What should I know about soybean oil before using it?

Soybean oil is available as a cooking oil and as an ingredient in insect repellents and skin care products. It cannot be marketed to treat or cure a disease.

Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.

Keep soybean oil out of the reach of children.

Natural substances like soybean oil naturally contain many different chemicals. The amount of each chemical and nutrient in a specific product can change for many reasons, including the area where the plant was grown, the weather during growth, the time of year it was harvested, and the way the oil was processed after it was harvested. If you switch to a new bottle or a different brand, you may not have the same effects or side effects because of this variability. Talk to your health care provider if you have questions or concerns.

Soybean oil is commonly sold as a mosquito repellent. However, its benefits for this use are not well understood. To protect against germs spread by mosquitoes, the Environmental Protection Agency (EPA) recommends the use of a proven mosquito repellent instead of, or along with, soybean oil. Learn more about effective mosquito repellents here.

What should I tell my health care provider before using soybean oil?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if soybean oil is right for you.

In particular, make sure that you discuss any of the following.

Soy Allergy. In most cases, a soy allergy is caused by the proteins in soybeans. These proteins are not usually found in soybean oil, especially highly refined soybean oil. However, some oils may contain small amounts of soy proteins. If you have a soy allergy, talk to your health care provider before using soybean oil products.

Pregnancy. It is not known if or how soybean oil could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if soybean oil passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does soybean oil interact with foods or drinks?

There are no known interactions between soybean oil and foods or drinks.

It is unknown if drinking alcohol will affect soybean oil.

Does soybean oil interact with medicines (drug interactions)?

There are no known interactions between soybean oil and medicines. Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

The interactions between soybean oil and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with soybean oil is incomplete. Always check with your health care provider before taking soybean oil with any medicines.

Dosing

What should I do if I accidentally use too much soybean oil?

If you or someone else has used too much soybean oil, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

Read the product label closely and speak with a health care provider about how to use soybean oil safely. Do not use more than recommended.