GENERIC NAME: GREEN TEA (Camellia sinensis) - ORAL
USES: Green tea contains caffeine and it has been used to increase alertness. Green tea has also been used for cancer prevention, to lower cholesterol, and to prevent/delay Parkinson's disease.Some herbal/diet supplement products have been found to contain possibly harmful impurities/additives. Check with your pharmacist for more details regarding the particular brand you use.The FDA has not reviewed this product for safety or effectiveness. Consult your doctor or pharmacist for more details.
HOW TO USE: Take this product by mouth as directed. Follow all directions on the product package. If you are uncertain about any of the information, consult your doctor or pharmacist.This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as headache, mental/mood changes such as irritability/nervousness) may occur if you suddenly stop using this medication. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions immediately.This product can decrease the amount of iron you get from food/supplements. If you have low iron levels, do not take green tea with meals or iron supplements. Take this product between meals.If your condition persists or worsens, or if you think you may have a serious medical problem, seek immediate medical attention.
SIDE EFFECTS: Nausea, diarrhea, upset stomach, headache, and dizziness may occur. If any of these effects persist or worsen, contact your doctor promptly.Tell your doctor immediately if any of these unlikely but serious side effects occur: fast/irregular heartbeat, mental/mood changes (e.g., nervousness, confusion), trouble sleeping, restlessness, shakiness (tremor), seizures.A very serious allergic reaction to this product is rare. However, seek immediate medical attention if you notice any of the following symptoms of a serious allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Quick GuidePortion Control Tips: Lose Weight and Stick to Your Diet
PRECAUTIONS: Before taking green tea, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.If you have any of the following health problems, consult your doctor or pharmacist before using this product: anemia (iron deficiency anemia), bleeding problems, diabetes, a certain eye condition (glaucoma), heart problems (e.g., irregular heartbeat, recent heart attack), stomach/intestinal problems (e.g., ulcers, reflux disease-GERD), liver problems, mental/mood disorder (e.g., anxiety, panic attacks), low levels of calcium in the blood, bone problems such as osteoporosis.Liquid preparations of this product may contain sugar and/or alcohol. Caution is advised if you have diabetes, alcohol dependence, or liver disease. Ask your doctor or pharmacist about using this product safely.Caution is advised when using this drug in children because they may be more sensitive to the effects of caffeine.During pregnancy, consult your doctor before using this product. Green tea contains caffeine. It is recommended that women limit caffeine during pregnancy. This product may also decrease folic acid. Discuss the risks and benefits with your doctor.This product may pass into breast milk and have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.Before using this product, tell your doctor or pharmacist of all prescription and nonprescription medications you may use, especially: other products that contain caffeine (e.g., drugs used to treat migraines/headaches or prevent sleepiness), drugs that can harm the liver (e.g., acetaminophen, amiodarone, carbamazepine, isoniazid, methotrexate, methyldopa, "statins" such as atorvastatin and lovastatin), "blood thinners" (e.g., warfarin), drugs affecting liver enzymes that remove caffeine from your body (e.g., cimetidine, fluvoxamine, verapamil, quinolone/macrolide antibiotics such as ciprofloxacin and erythromycin, estrogens including hormonal birth control such as the pill/patch/ring), lithium, stimulants (e.g., amphetamine, ephedra/ma huang, pseudoephedrine), theophylline.Check the labels on all your medicines (e.g., cough-and-cold products, diet aids, headache medicines) because they may contain caffeine or other stimulants (e.g., ephedra/ma huang, phenylpropanolamine) that could increase your heart rate or blood pressure. Ask your pharmacist about using those products safely.While taking this product, avoid drinking large amounts of beverages containing caffeine (e.g., coffee, tea, certain soft drinks) or eating large amounts of chocolate.This product can interfere with certain medical/laboratory tests (e.g., chemical stress tests using adenosine/dipyridamole, urine tests for calcium/catecholamines), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this product.Stop taking this product 24 hours before a dipyridamole or adenosine stress test and at least 4 hours before lung function tests. Ask your doctor for more details.This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
OVERDOSE: If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: seizures, irregular heartbeat.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
STORAGE: Refer to storage information printed on the package. If you have any questions about storage, ask your pharmacist. Keep all medications and herbal products away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised March 2013. Copyright(c) 2013 First Databank, Inc.
Related Disease Conditions
Cholesterol (Lowering Your Cholesterol)
High cholesterol and triglyceride levels increase the risk of cardiovascular disease. Getting your cholesterol and triglyceride...
Prostate cancer is the most common cancer in men after skin cancer. Risk factors include age, family history, ethnicity, and...
Sleep Disorders (How to Get a Good Night's Sleep)
A number of vital tasks carried out during sleep help maintain good health and enable people to function at their best. Sleep...
STDs in Men
Sexually transmitted diseases (STDs) are infections transmitted during sexual contact. They may be caused by viruses, bacteria,...
Certain behavioral, lifestyle, and environmental factors contribute to cancer. Cancer prevention involves modifying these factors...
COPD vs. Emphysema (Differences Similarities)
COPD (chronic obstructive pulmonary disease) is the term doctors and other health care professionals use to describe a group of...
Treatment & Diagnosis
Medications & Supplements
Prevention & Wellness
- Americans Are Changing Their Supplements of Choice
- Over 100 Drugs Pose Risk to Heart Failure Patients
- Health Tip: Cleanse Your Body Naturally
- A Daily Cup of Tea May Soothe Your Heart
- Green Tea Linked to Lower Risk for Dementia
- Cancer Doctors Don't Discuss Herbs, Supplements With Patients
- Green Tea May Interfere With a Blood Pressure Medicine
- Health Tip: Eat Right for Healthier Sight
- Black Tea Linked to Lower Diabetes Risk
- Green Tea and Cancer Prevention: New Clues
- The Link Between Chocolate & the Nobel Prize
- Could Unroasted Coffee Beans Help You Shed Pounds?
- Could Soy Help Lower Your Blood Pressure?
- Caffeine May Alter Women's Estrogen Levels
- Green Tea Doesn't Prevent Breast Cancer, Study Finds
- Tea, Coffee Drinkers Have Lower Heart Risk
- Study: Shark Cartilage No Help for Cancer
- FDA: Labels Misleading on Major Food Brands
Quick GuidePortion Control Tips: Lose Weight and Stick to Your Diet
Daily Health News
Nutrition and Healthy Eating Resources
Subscribe to MedicineNet's Weight Loss/Healthy Living Newsletter
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Top green tea (Camellia sinensis)-oral Related Articles
Anxiolytics for Anxiety Drug Class
Anxiolytics (anti-anxiety, anti-panic) is a group of drug classes (for example, antidepressants, antihistamines, and benzodiazepines) that are prescribed for the treatment of anxiety disorders. Anxiolytics work (mechanism of action) depending upon to which drug class it belongs. Anxiety disorder drugs cause similar side effects, for example:
- Stomach upset
- Weight gain
More serious side effects of anti-anxiety drugs include:
- Suicidal thoughts
- Dry mouth
- Elevated blood pressure
- Blurred vision
- Abnormal heartbeat
- Low blood pressure when standing (orthostatic hypotension)
Some natural herbal products and supplements like St. John's wort, ginkgo biloba, valerian, lemon balm, and chamomile may be helpful in reducing anxiety. Talk with your doctor about taking herbal or other supplement products.
Anxiolytics have several drug interactions. This type of drug is not recommended during pregnancy or while breastfeeding.
Cancer PreventionCertain behavioral, lifestyle, and environmental factors contribute to cancer. Cancer prevention involves modifying these factors to decrease cancer risk. Tobacco use, alcohol consumption, physical inactivity, inadequate fruit and vegetable intake, and obesity increase the risk of certain cancers. Vaccines, genetic testing, and cancer screening also play a role in cancer prevention.
Cholesterol ManagementHigh cholesterol and triglyceride levels increase the risk of cardiovascular disease. Getting your cholesterol and triglyceride levels in an optimal range will help protect your heart and blood vessels. Cholesterol management may include lifestyle interventions (diet and exercise) as well as medications to get your total cholesterol, LDL, HDL, and triglycerides in an optimal range.
COPD vs. Emphysema Differences Similarities
COPD (chronic obstructive pulmonary disease) is the term doctors and other health care professionals use to describe a group of serious, progressive (worsens over time), chronic lung diseases that include emphysema, chronic bronchitis, and sometimes asthma. The number one cause of COPD or emphysema, is smoking, and smoking is the third leading cause of death in the US. When a person first develops COPD, he or she may not have any symptoms. As the disease progresses, the symptoms worsen and become more severe and include:
- Difficulty breathing with exertion or physical activity, which in the advanced stages, eventually leads to breathlessness all of the time.
- Chronic cough
- Excessive phlegm production
- Upper respiratory infections like the flu or common cold.
- A barrel-shaped chest
- A bluish tint to the skin from lack of oxygen
- Chest tightness
- varenicline (Chantix) to quit smoking
- The antidepressant and bupropion (Zyban) to reduce nicotine withdrawals
- Drugs that are prescribed for another condition (off label), for example, nortriptyline (Pamelor) and clonidine (Catapres)
- Short-term bronchodilators, for example, albuterol (Ventolin, Proventil)
- Long-term bronchodilators, for example, salmeterol (Serevent) and formoterol (Foradil)
- Anticholinergic bronchodilators, for example, ipratropium (Atrovent) and tiotropium (Spiriva)
- Combined drugs using steroids and long acting bronchodilators
- Roflumilast (Daxas, Daliresp)
You can prevent getting COPD or emphysema if you:
- Quit smoking and making healthy lifestyle changes
- Avoid secondhand smoke
- Avoid home and workplace air pollutants
- Prevent upper respiratory tract infections
There is a genetic cause of COPD called alpha-1 antitrypsin.
CDC. "Chronic Obstructive Pulmonary Disease (COPD)." Updated: Sep 16, 2016.
NIH; National Heart, Lung, and Blood Institute. "COPD National Action Plan." Updated: May 15, 2017.
NIH; National Heart, Lung, and Blood Institute. "What is COPD?" Updated: Apr 28, 2017.
U.S. Department of Health and Human Services. "COPD (Chronic Obstructive Pulmonary Disease)." Updated: Oct 31, 2014.
Victoria State Government. "Emphysema." Updated: Nov 2014.
Sharafkhaneh, A. et al. Emphysema. Proc Am Thorac Soc. 2008 May 1; 5(4): 475–477. doi: 10.1513/pats.200708-126ET
Boka, K. "Emphysema." Medscape. Updated: Aug 31. 2016.
Kleinschmidt, P. "Chronic Obstructive Pulmonary Disease (COPD) and Emphysema in Emergency Medicine." Medscape. Updated: Jun 08, 2017.
Prostate CancerProstate cancer is the most common cancer in men after skin cancer. Risk factors include age, family history, ethnicity, and diet. Prostate cancer is diagnosed by digital rectal exam, prostate specific antigen (PSA) test, and prostate biopsy. Symptoms may include frequent need to urinate, incontinence, pain, blood in the urine, fatigue, and more. Prognosis and treatment depend on cancer staging. Watchful waiting, surgery, radiation, cryotherapy, and other management strategies are available. Research and clinical trials strive to find new and better treatments for prostate cancer.
A number of vital tasks carried out during sleep help maintain good health and enable people to function at their best. Sleep needs vary from individual to individual and change throughout your life. The National Institutes of Health recommend about 7-9 hours of sleep each night for older, school-aged children, teens, and most average adults; 10-12 for preschool-aged children; and 16-18 hours for newborns. There are two stages of sleep; 1) REM sleep (rapid-eye movement), and 2) NREM sleep (non-rapid-eye movement). The side effects of lack of sleep or insomnia include:
- Feeling sleepy during the day
- Concentration or memory problems
Lack of sleep and insomnia can be caused by medical conditions or diseases, medications, stress, or pain. The treatment for lack of sleep and insomnia depends upon the cause.
STDs in Men Overview
Sexually transmitted diseases (STDs) are infections transmitted during sexual contact. They may be caused by viruses, bacteria, or parasites. STDs in men cause no symptoms or symptoms like
genital burning, itching, sores, rashes, or discharge.
Common infections that are sexually transmitted in men include gonorrhea, chlamydia, syphilis, hepatitis C and B, genital warts, human papillomavirus (HPV), and genital herpes.
Some STDs in men are treatable while others are not. STDs are diagnosed with tests that identify proteins or genetic material of the organisms causing the infection. The prognosis of an STD depends on whether the infection is treatable or not. Use of latex condoms can help reduce the risk of contracting an STD but it does not eliminate the risk entirely.