Overview

Neem (Azadirachta indica) is a tree. Neem seed oil is commonly used as a pesticide on plants and crops. Various parts of the tree are also made into dietary supplements and products that are applied to the skin. Although neem is used for many health problems, its benefits are not well defined. Neem seems to be well tolerated when taken by mouth, but there is not enough research to know what side effects it may cause. When applied to the skin, it may cause redness, itchiness, or dryness. Before using neem, make sure to tell your health care provider about any health conditions you have and medicines you are taking.

Uses

What is neem used for?

Neem (Azadirachta indica) is taken by mouth or applied to the skin for many reasons. It is sometimes applied to the skin to disinfect wounds and manage certain infections or infestations. Neem may also be added to mouthwash or toothpaste to help reduce the risk of cavities. However, its benefits for any use are not well defined.

Neem seed oil is commonly used as a pesticide on garden plants and crops.

Note: The FDA has not reviewed neem for safety and effectiveness. Learn more about dietary supplements here.

How does neem work (mechanism of action)?

Neem is a tree called Azadirachta indica. Its leaves have a long history of use in the traditional medicine system in India (Ayurveda). The leaves, flowers, and stems may be found in dietary supplements, mouthwashes, toothpastes, and other products. Neem seeds are used to make neem oil, a common pesticide with a distinctive smell and a bitter taste.

Neem leaves contain many different chemicals that may kill the microbes that cause infections, including fungi and bacteria. This has led to interest in using neem leaf to disinfect cuts, burns, or other wounds. However, its benefits for cleaning the skin or treating skin infections are not well defined. Neem leaf is also added to some mouthwash and toothpaste products, but there is no clear evidence that neem can reduce the growth of bacteria in the mouth or lower the risk of cavities.

Neem seed oil is a pesticide used on a wide range of plants and crops worldwide. Many different chemicals in neem oil can help kill common pests, including insects and fungi. The most potent insecticide in neem oil is azadirachtin, and some neem-based insecticides are standardized to contain a certain amount of this chemical. But other pesticide products contain no azadirachtin. These products, called clarified hydrophobic neem oil (CHNO), are used to prevent and treat fungal infections on plants.

The common use of neem oil against plant insects has led to interest in its possible use for certain health problems, including worms, parasites, and lice. But the benefits and risks of neem oil for these uses are not well defined. If you are concerned that you have a worm or parasite infection, seek medical help. Do not try to treat these problems on your own. If you have head or body lice, speak to a health care provider about your treatment options.

Although neem dietary supplements are sometimes taken by mouth for various health problems, the benefits of oral neem for any use are not well defined.

Herbal products, such as neem, naturally contain many different chemicals. The amounts of each chemical in a specific neem 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 neem?

You should store neem 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 neem?

When applied to the skin, neem may cause itchiness, dryness, or redness. Although neem seems to be well tolerated when taken by mouth, there is not enough research to know what the common side effects may be. Tell your health care provider if you have any side effects that bother you.

There may be other side effects of neem 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 neem?

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

Severe Allergic Reactions. Neem may cause allergic reactions, which can be serious. Stop using neem 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

Fertility Problems in Men.There is some concern that taking neem by mouth may reduce the amount of sperm that your body produces. This may make it more difficult for you to get your partner pregnant. If you have concerns, talk to your health care provider before taking any products that contain neem.

Precautions

Who should not use neem?

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

• Azadirachta indica
• Margosa oil
• Neem
• Any of the ingredients in the specific product

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

What should I know about neem before using it?

Neem is a dietary supplement and is also added to 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 neem out of the reach of children.

If you are applying neem for a skin problem, stop using it once your symptoms get better. If your symptoms (such as irritation, pain, redness, or swelling) worsen or do not get better while using the product, stop using it and contact your health care provider. You should also tell your health care provider if you get a rash or infection while using neem.

Some products that contain neem may be marketed as spermicides. These products are meant to be placed into the vagina to kill sperm before it enters the uterus. But it is not clear if these products can consistently kill sperm. You should not rely on neem-based spermicide products as a form of birth control. Talk to your health care provider about your birth control options.

Herbal products, such as neem, naturally contain many different chemicals. The amount of each chemical in a specific neem product can change for many reasons, including the area where the tree was grown, the weather during growth, the time of year it was harvested, and the way it was processed after harvesting. 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.

Neem is available in many different forms, including teas, oils, and capsules. It is also available in products that are applied to the skin, such as oils, lotions, and creams. Each of these forms may contain different amounts of the chemicals that are naturally found in the plant.

Neem may be made from different parts of the plant. Most products that are applied to the skin or mouth are made from the leaf, although some may also contain seed oil. Dietary supplements may contain the leaves, stems, twigs, or flowers. Products that are used as pesticides are made from the seed. Each of these plant parts contains different chemicals that may have different effects on the body. It is important to read the label to confirm which part of the plant was used to make that product.

The FDA has not tested neem products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.

What should I tell my health care provider before using neem?

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 neem is right for you.

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

Deep Wounds, Serious Burns, or Bites.Ask your health care provider before using neem on a deep wound, an open wound, a serious burn, or an animal bite. It may be unsafe to use neem on these wounds, and they may need other forms of treatment.

Other Medicines and Supplements.Neem may interact with other medicines and supplements. Before taking neem, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how neem 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 neem passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does neem interact with foods or drinks?

There are no known interactions between neem and foods or drinks.

It is unknown if drinking alcohol will affect neem.

Does neem interact with medicines (drug interactions)?

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.

In particular, make sure that you discuss if you are taking a medicine for diabetes.

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

Dosing

What should I do if I accidentally use too much neem?

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

Products that contain neem come in many different forms and may contain various parts of the plant. Read the product label closely and speak to a health care provider about how to take neem safely. Do not take double or extra doses, even if you miss a dose.