Overview

Black seed (Nigella sativa) is a flowering plant native to Asia and the Mediterranean. Its seed has been used to make medicine for thousands of years.

Black seed might have effects in the body that help boost the immune system, fight cancer, prevent pregnancy, reduce swelling, and lessen allergic reactions by acting as an antihistamine.

People commonly use black seed for asthma, hay fever, diabetes, high blood pressure, eczema, weight loss, menstrual cramps, and many other conditions, but there is no good scientific evidence to support many of these uses. There is also no good evidence to support using black seed for COVID-19.

Uses & Effectiveness

Possibly Effective for

  • Acne. Applying a gel containing black seed extract to the skin might help to improve acne.
  • Hay fever. Taking black seed oil by mouth daily might improve allergy symptoms in people with hay fever.
  • Asthma. Taking black seed by mouth along with asthma medicines can improve coughing, wheezing, and lung function in some people with asthma. But it seems to work only in people with very low lung function before treatment.
  • A lung disease that makes it harder to breathe (chronic obstructive pulmonary disease or COPD). Taking black seed oil by mouth helps to improve lung function in people with COPD who are also using prescribed inhalers.
  • Diabetes. Taking black seed powder or black seed oil by mouth daily seems to improve blood sugar levels in people with diabetes.
  • A digestive tract infection that can lead to ulcers (Helicobacter pylori or H. pylori). Taking black seed powder along with standard therapies might help to get rid of this infection.
  • High blood pressure. Taking black seed powder or black seed oil by mouth might reduce blood pressure by a small amount in healthy adults. But it's not clear if it helps people with high blood pressure.
  • High levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). Taking black seed supplements by mouth can slightly lower total cholesterol, low-density lipoprotein (LDL or "bad") cholesterol, and triglycerides, and increase high-density lipoprotein (HDL or "good") cholesterol in people with or without hyperlipidemia.
  • Breast pain (mastalgia). Applying a gel containing black seed oil to the breasts during the menstrual cycle seems to reduce pain.

There is interest in using black seed for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: Black seed is commonly consumed in foods. Black seed oil and black seed powder are possibly safe when taken in larger amounts for up to 3 months. There isn't enough reliable information to know if larger amounts are safe when used for more than 3 months. Black seed can cause allergic rashes in some people. It can also cause stomach upset, vomiting, or constipation.

When applied to the skin: Black seed oil or gel is possibly safe when used short-term. It can cause allergic rashes in some people.

Special Precautions and Warnings

When taken by mouth: Black seed is commonly consumed in foods. Black seed oil and black seed powder are possibly safe when taken in larger amounts for up to 3 months. There isn't enough reliable information to know if larger amounts are safe when used for more than 3 months. Black seed can cause allergic rashes in some people. It can also cause stomach upset, vomiting, or constipation.

When applied to the skin: Black seed oil or gel is possibly safe when used short-term. It can cause allergic rashes in some people.

Pregnancy: Black seed is commonly consumed in foods. But taking amounts greater than those found in foods while pregnant is likely unsafe. Black seed can slow down or stop the uterus from contracting.

Breast-feeding: There isn't enough reliable information to know if black seed is safe to use when breast-feeding. Stay on the safe side and avoid use.

Children: Black seed oil is possibly safe for children when taken by mouth short-term and in recommended amounts by weight.

Bleeding disorders: Black seed might slow blood clotting and increase the risk of bleeding. Black seed might make bleeding disorders worse.

Surgery: Black seed might slow blood clotting, reduce blood sugar, and increase sleepiness in some people. This can interfere with drugs used during and after surgical procedures and cause severe side effects. Stop using black seed at least two weeks before a scheduled surgery.

Interactions

    Moderate Interaction

    Be cautious with this combination

  • Amlodipine (Norvasc) interacts with Black Seed

    Amlodipine lowers blood pressure. Black seed also lowers blood pressure. Taking black seed with amlodipine might lower blood pressure too much. People taking black seed along with amlodipine should monitor their blood pressure.

  • Medications that increase serotonin levels in the brain (Serotonergic Drugs) interacts with Black Seed

    Black seed might increase a brain chemical called serotonin. Some medications also have this effect. Taking black seed along with these medications might increase serotonin too much. This might cause serious side effects including heart problems, seizures, and vomiting.

  • Medications for diabetes (Antidiabetes drugs) interacts with Black Seed

    Black seed might lower blood sugar levels. Taking black seed along with diabetes medications might cause blood sugar to drop too low. Monitor your blood sugar closely.

  • Medications that decrease the immune system (Immunosuppressants) interacts with Black Seed

    Black seed can increase the activity of the immune system. Some medications, such as those used after a transplant, decrease the activity of the immune system. Taking black seed along with these medications might decrease the effects of these medications.

  • Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with Black Seed

    Black seed might slow blood clotting. Taking black seed along with medications that also slow blood clotting might increase the risk of bruising and bleeding.

  • Medications for high blood pressure (Antihypertensive drugs) interacts with Black Seed

    Black seed might lower blood pressure. Taking black seed along with medications that lower blood pressure might cause blood pressure to go too low. Monitor your blood pressure closely.

  • Sedative medications (CNS depressants) interacts with Black Seed

    Black seed might cause sleepiness and slowed breathing. Some medications, called sedatives, can also cause sleepiness and slowed breathing. Taking black seed with sedative medications might cause breathing problems and/or too much sleepiness.

  • Cyclosporine (Neoral, Sandimmune) interacts with Black Seed

    Black seed might decrease levels of cyclosporine in the blood. This might reduce how well cyclosporine is able to work.

  • Water pills (Diuretic drugs) interacts with Black Seed

    Black seed can decrease potassium levels. "Water pills" can also decrease potassium levels. Taking black seed along with "water pills" might make potassium levels drop too low.

  • Clopidogrel (Plavix) interacts with Black Seed

    Clopidogrel can slow blood clotting. Black seed might also slow blood clotting. Taking black seed along with clopidogrel might increase the chances of bruising and bleeding.

  • Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates) interacts with Black Seed

    Some medications are changed and broken down by the liver. Black seed might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Phenytoin (Dilantin) interacts with Black Seed

    Phenytoin is used to control some types of seizures. Black seed may increase or decrease levels of phenytoin in the blood. Taking black seed with phenytoin might reduce the effects or increase the risk of having side effects to phenytoin.

  • Warfarin (Coumadin) interacts with Black Seed

    Warfarin is used to slow blood clotting. Black seed might increase the effects of warfarin, which could increase the risk of bleeding.

  • Sildenafil (Viagra) interacts with Black Seed

    Black seed might reduce levels of sildenafil in the body. Taking black seed with sildenafil might reduce the effects of sildenafil.

    Minor Interaction

    Be watchful with this combination

  • Prednisolone interacts with Black Seed

    Black seed might decrease levels of prednisolone in the blood. This might reduce the effects of prednisolone.

Dosing

Black seed oil has most often been used by adults in doses of 1-2.5 grams by mouth daily for 4-12 weeks. Black seed powder has most often been used in doses of 1-2 grams by mouth daily for 8-12 weeks. Speak with a healthcare provider to find out what dose might be best for a specific condition.
View References

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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is licensed from Therapeutic Research Center, LLC. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
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