Guarana – Weight Loss Benefits and Side Effects


What is Guarana?


Scientific name: Paullinia cupana

This maple plant is common to Brazil and is famous for its seeds which are similar to coffee beans.

Uses: Used as a medicine, supplement and a major ingredient in carbonated drinks. Also used as ingredient in many popular fat burning supplements.

Similar fat-burning ingredients:
Green coffee, green tea, yerba mate, etc.

A part of the maple family, this climbing plant is known for its coffee-like seeds, both in appearance and their caffeine content. The seeds of Guarana are black in colour and have about twice the caffeine as found in coffee beans. Guarana seeds have 2 to 4.5 percent of caffeine as compared to coffee beans that have 1 to 2 percent. The high concentration of caffeine protects the plant from herbivore animals due to its bitter taste. Guarana is used as an effective stimulant because of its high caffeine composition.

Benefits of Guarana for Weight Loss

Guarana has been popular for the following effects:

  • It suppresses appetite
  • It boosts metabolism
  • It increases expenditure of energy
  • It increases the breakdown of fat
  • Enhance exercise performance
  • Promotes weight loss
  • Serves as diuretic
  • Mobilizes stored fat

How Does It Work?

Because of the high caffeine content in guarana, its effects as a stimulant for weight loss include the following:

  • Increasing heart rate, boosting metabolism and suppressing appetite. If taken before meals, guarana sufficiently decreases your appetite, making you eat less which leads to weight loss.
  • Having a thermogenic effect on the body, i.e. more calories are burned because increased heat is produced in the body Through thermogenesis, fat oxidation and energy utilization is increased.
  • As a diuretic, caffeine promotes elimination of excess water weight through urine.

Other Benefits

Guarana is popularly used for many reasons including the following:

  • Commercial preparation of caffeine
  • Carbonated fizzy drinks and other sweetened beverages
  • Herbal teas, energy shots and drinks
  • Possible treatment for anxiety, diarrhoea, heart problems, joint pain, malaria, fluid retention and hypotension
  • Effective against fever and headaches
  • Improved short-term performance
  • Reduces physical and mental fatigue
  • Fights bloating and other digestive problems
  • Enhances intellectual performance

Clinical Studies

Clinical Studies on Guarana

In a study (source) performed in 2002, it was found that a mixture containing yerba mate, guarana and damiana helps in losing weight. The study was over a period of 45 days and 44 overweight but healthy participants took part in the study. The volunteers were either given the mixture of above mentioned ingredients or a placebo. After completion of the study, significant weight loss was observed in the test group.

Another study (source) in 2001 studied the effect of guarana and ma huang in a randomized trial consisting of 67 volunteers for 8 weeks. Volunteers were either given a combination of the two ingredients or a placebo. At the end of the study, the guarana-ma-huang group lost 4 kg (on average) while the placebo group was only able to shed off 0.4 kg.

Side Effects

Guarana is characterized as safe by the FDA to be used in amounts as present in foods or when taken for medicinal uses. There is no standard dose for guarana but a dose of 200-800 mg per day is typically used by most people. High doses are linked to serious side effects such as:

  • Diarrhoea
  • Anxiety
  • Diabetes
  • Hypertension
  • Bleeding disorders
  • Heart disease
  • Irritable Bowel Syndrome (IBS)
  • Glaucoma
  • Insomnia
  • Nervousness
  • Nausea
  • Vomiting
  • Heartburn and flatulence
  • Heart palpitations
  • Restlessness

A word of caution

It is necessary to ensure that your daily dose  of guarana doesn’t exceed the recommended dosage prescribed by health regulatory bodies. More than 300 mg of caffeine per day can lead to increased excretion of calcium from the bones which might cause osteoporosis. You should exercise more caution if you are:

  • Postmenopausal
  • Expectant or breast-feeding mother
  • Suffering from heart disease
  • Hypertensive


Guarana seeds

Guarana seeds are packed with caffeine, which accounts for its many benefits as a stimulant. This effect of guarana is the reason for its use as a weight loss supplement. Many studies have supported the role of guarana in weight loss, but due to the high caffeine content, caution is advised to everyone deciding to use guarana as a weight loss supplement. Proper care and caution needs to be exercised while starting with guarana and recommended doses need to be followed. As with all other supplements, it is best to use guarana with a healthy routine comprising of diet and exercise, in order to reap the maximum benefits of this plant.