Mega-t Green Tea Side Effects

Mega-T Green Tea supplements are appetite suppressants meant to help you lose weight. The supplement provides 600 mg green tea along with bladderwrack, eleuthero, guarana, garcinia cambogia and chromium, according to product information. Always check with a doctor before trying a new supplement, and be advised that the ingredients in Mega-T can cause side effects.

Green Tea Effects

Concentrated green tea extracts can cause liver damage, say the experts at the National Center for Complementary and Alternative Medicine. Liver damage is rare, but if you have a liver disorder you should avoid green tea supplements. If you develop liver trouble symptoms such as dark urine, abdominal pain or jaundice when using a green tea supplement you need to contact your doctor, according to NCCAM.

Green tea extracts contain caffeine, which can cause anxiety, insomnia, irritability, frequent urination, upset stomach, diarrhea or nausea, according to NCCAM. Green tea also can make anticoagulant medicines like warfarin or aspirin less effective. University of Maryland Medical Center advises that green tea can also interact with the heart medicine adenosine, beta-lactam antibiotics, anxiety medicines called benzodiazepines, blood pressure medications, chemotherapy, lithium, anti-psychotic medication clozapine, antidepressants and oral contraceptives. If you use a green tea supplement along with ephedrine it can cause tremors, agitation, insomnia and weight loss. Taking it with phenylpropanolamine, found in cough and cold medicines and weight loss products, can lead to a severe increase in blood pressure and mania, warn the experts at UMMC.

Guarana Effects

Guarana also contains high caffeine content that can lead to side effects. Guarana can cause gastric irritation, diuretic effects, insomnia, nervousness and restlessness, according to "The Essential Herb-Drug-Vitamin Interaction Guide," by George T. Grossberg and Barry Fox. Guarana can interfere with the action of the anxiety drug alprazolam. You increase risk for low potassium levels if you take guarana with calcium-channel blockers like bepridil. Taking it with diabetes medicines like acarbose and insulin can have unpredictable effects on your blood sugar levels. Gurarana can increase risk of side effects from certain drugs including estrogens, progesterone, and medicines used to treat infections such as fluconazole and cinoxacin. The caffeine in guarana also can increase risk for high blood pressure when this herb is taken with monoamine oxidase, or MAO, inhibitors like phenelzine. It can increase stimulation of your central nervous system when taken with bronchodilator drugs like albuterol. Taking guarana with clozapine can lead to increased psychotic symptoms. It can increase toxic effects of theophylline, which is used for asthma or wheezing associated with conditions like bronchitis. Guarana's caffeine also can increase side effects of riluzole, taken for Lou Gehrig's disease, say Grossberg and Fox.

Bladderwrack Effects

Bladderwrack can trigger or worsen cases of hyperthyroidism, meaning overactive thyroid, can cause an allergic reaction and may cause acne, say Grossberg and Fox. It also can lead to lowered blood sugar levels, according to the National Institutes of Health. That means you need to use caution if you have diabetes or hypoglycemia or take drugs or herbs that affect blood sugar. Be careful if you have a bleeding disorder or take medicines or supplements with anticoagulant properties, because bladderwrack can have blood-thinning properties, according to NIH. Combining these can increase risk for bruising or bleeding. Bladderwrack also may be contaminated with heavy metals, according to NIH, so you need to avoid it if you are pregnant or nursing.

Garcinia Cambogia Effects

Garcinia cambogia can cause dry mouth, dizziness, headache and gastrointestinal issues such as diarrhea or nausea, according to Drugs.com. If you have diabetes, Alzheimer's or any other dementia syndromes or are pregnant you need to avoid garcinia cambogia, according to the National Cancer Institute. Garcinia cambogia can interact with heart medicines called antiarrhythmics, calcium-channel blockers, nitrates, beta-adrenoreceptor blocking drugs and cardiac glycosides. If taken with muscle relaxants or terfenadine, garcinia can increase risk for hypokalemia, meaning low blood levels of potassium, and heart arrhythmia, according to the National Cancer Institute.

Eleuthero Effects

Eleuthero is also known as Siberian ginseng or eleutherococcus. High doses can cause insomnia, irritability and anxiety. Other side effects can include headache, skin eruptions, diarrhea, high blood pressure, drowsiness, confusion, irregular heart rhythm, nosebleed and vomiting. It also may lower blood sugar, according to Drugs.com. You need to avoid it because it can worsen your condition if you have high blood pressure, narcolepsy or sleep apnea, according to UMMC. Avoid eleuthero if you are pregnant or nursing. Eleuthero can interact with digoxin, blood thinning medicines and sedatives.

Chromium Effects

Chromium supplements can change the amount of insulin you need if you are diabetic, according to Drugs.com. It also can interact with tobacco and alcohol. Avoid chromium if you are pregnant or nursing because excessive chromium may harm your baby, according to Drugs.com.