Interactions Between Effexor And Thermofit

In our latest question and answer, the pharmacist discusses the possible drug interaction between Thermofit and Effexor.

Interactions Between Effexor And Thermofit
Jan 29, 2019

Sue asked

I am on 75mg of Effexor and wondered if I could take the diet supplement called Thermofit? Would there be interactions?


There are no known drug interactions between It Works! Thermofit and Effexor (venlafaxine). However, there have been no studies done between these two so there simply may be a lack of data to make a definitive determination.

It's always tricky to evaluate drug interactions between over-the-counter supplements and prescription products. Aside from the lack of data on interactions, most supplements contain not just one ingredient but several, making evaluations harder.

Regarding Effexor and Thermofit, let's break down the ingredients in Thermofit and see if there are known interactions with the individual components.

Thermofit Ingredients

Thermofit Label

As you can see from the 'Supplement Facts' label, it contains:

  • Vitamin B12
  • Chromium
  • Capsicum Fruit Extract (Capsimax)
  • Raspberry Ketones
  • Acai 5:1 Extract
  • Proprietary blend
    • Green Tea Extract
    • Guarana Seed Extract
    • Bitter Melon Extract
    • Dandelion Fruit Extract
    • Gymnema Leaf Extract

    In the next sections, we will take a look and see if there are known interactions between any of these ingredients and Effexor.

    Thermofit - Effexor Interactions

    As shown above, Thermofit contains a variety of ingredients so each must be considered when it comes to interactions.

    Vitamin B12

    Also known as cyanocobalamin, vitamin B12 is a water-soluble vitamin found in a variety of foods. It is often taken as a supplement for its purported effects on increasing energy.

    Vitamin B12 has very few drug interactions, and none have been documented with Effexor.

    Interaction With Effexor?
    There is no known interaction between Vitamin B12 and Effexor.


    Chromium is a mineral found in food and supplements.

    It is included in supplements for weight loss as it has evidence showing that it can decrease fasting blood glucose, insulin levels and increase insulin sensitivity.

    There are few known drug interactions with chromium, with the most concern being with antidiabetes drugs as they may have additive blood sugar-lowering effects.

    Interaction With Effexor?
    There is no known interaction between chromium and Effexor.

    Capsicum Fruit Extract (Capsimax)

    Capsicum naturally occurs in various peppers and has recently been utilized in supplements as well as over the counter pain relievers.

    In weight loss supplements, it is thought to increase metabolism and have a blood sugar-lowering effect.

    Capsicum is associated with more drug interactions than many other supplements, mostly because it has been studied in greater detail.

    Some interactions with capsicum include:

    There are no known interactions with Effexor however.

    Interaction With Effexor?
    There is no known interaction between capsicum and Effexor.

    Raspberry Ketones

    Raspberry ketones have been evaluated in small controlled clinical trials which show the ketones may have mild weight loss properties and could potentially reduce body fat.

    Raspberry ketones are thought to have mild stimulant properties as well and palpitations have been reported as a possible side effect.

    Effexor may cause increases in blood pressure and therefore, combining with raspberry ketones might increase the risk of adverse cardiovascular effects.

    Interaction With Effexor?
    Although more data is needed, taking Effexor with raspberry ketones may increase the risk of cardiovascular adverse effects. No interaction has been documented however.

    Acai 5:1 Extract

    Acai is one of the most commonly used ingredients in weight loss aids.

    Research suggests that it has a variety of positive metabolic effects, including a lowering of fasting glucose and total cholesterol levels.

    There have not been any reports of interactions with antidepressants like Effexor.

    Interaction With Effexor?
    There is no known interaction between Acai and Effexor.

    Green Tea Extract

    Green tea has been extensively studied and has a large body of evidence for it.

    It seems to lower cholesterol and triglycerides and may even increase athletic performance by increasing oxygen uptake.

    Green tea also contains caffeine, which can increase alertness, energy, and metabolism.

    Caffeine can cause transient increases in blood pressure. One possible side effect of Effexor is an increase in blood pressure, due to its effects on the neurotransmitter norepinephrine. Therefore, a possible interaction exists, although it is considered relatively minor.

    Interaction With Effexor?
    Green tea extract contains caffeine, which could raise blood pressure. A possible side effect of Effexor is increased blood pressure so, theoretically, they could have additive effects.

    Guarana Seed Extract

    Guarana, a common ingredient in weight loss aids and energy drinks, contains between 3-6% caffeine. Therefore, it works by exerting a stimulant effect.

    Caffeine, as discussed in the green tea section, can increase blood pressure.

    Interaction With Effexor?
    Guarana contains caffeine, which could raise blood pressure. A possible side effect of Effexor is increased blood pressure as well so they could have additive effects.

    Bitter Melon Extract

    Bitter melon has extensive research showing that it may potentially improve glucose tolerance and reduce overall blood glucose levels. It may also help to lower blood pressure.

    Regarding interactions, there doesn't appear to be many but since it can lower blood glucose levels and blood pressure, it may have additive effects with those drugs. Nothing has been reported with Effexor.

    Interaction With Effexor?
    There is no known interaction between bitter melon extract and Effexor.

    Dandelion Fruit Extract

    Dandelion root is most commonly used in weight loss supplements for its diuretic effects and can help reduce overall weight by causing a reduction in body fluid.

    There have been no interactions reported with Effexor.

    Interaction With Effexor?
    There is no known interaction dandelion fruit extract and Effexor.

    Gymnema Leaf Extract

    Gymnema is a popular supplement and evidence suggests it can aid in weight loss and may reduce the effect sugar has on the body.

    It has few known drug interactions and none as far as we know with Effexor.

    Interaction With Effexor?
    There is no known interaction between Gymnema leaf extract and Effexor.


    Although it is nearly impossible to definitively say that prescription medications like Effexor have no interactions with a given dietary supplement, after looking at all the ingredients in Thermofit, there doesn't appear to be anything major.

    The caffeine content of Thermofit (from green tea and guarana) may increase blood pressure, which Effexor can do as well, but the effect shouldn't be significant for most individuals.

    Additionally, the stimulating effects of raspberry ketones may be a concern, but no specific interactions have been reported.

    As with all dietary supplements, be sure to let your doctor know you are taking it so you can be appropriately monitored for effectiveness and adverse reactions.

    1. Beneficial effect of chromium supplementation on serum triglyceride levels in NIDDM. PubMed
    2. Effect of Gymnema sylvestre Administration on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion. PubMed
    3. The action of Taraxacum officinale extracts on the body weight and diuresis of laboratory animals. PubMed
    4. Improvement in glucose tolerance due to Momordica charantia (karela). PubMed
    5. Effect of endurance training supplemented with green tea extract on substrate metabolism during exercise in humans. PubMed
    6. Cross sectional study of effects of drinking green tea on cardiovascular and liver diseases. PubMed
    7. Effects of Açai (Euterpe oleracea Mart.) berry preparation on metabolic parameters in a healthy overweight population: a pilot study. PubMed
    8. Eight weeks of supplementation with a multi-ingredient weight loss product enhances body composition, reduces hip and waist girth, and increases energy levels in overweight men and women. PubMed

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