Garcinia Cambogia is the predated named for the Garcnia Gummi-Gutta fruit. It’s also commonly referred to as the Gambooge Pazham Puzhi, Bitter Kola, Hydroxycitric acid, or Malabar Tamarind.
Malabar Tamarind is a name that stems from its country of origin, Indonesia. 
The Garcinia Cambogia tree grows to around 10-15 feet and bears fruits that look like green pumpkins, but approximately the size of a tomato . The visual similarity to a pumpkin ends at its shape, because it has a robust green skin and a fleshy interior that is pale yellow.The fruits contain seeds that are approximately 30% fat and so are used in the production of ghee .
It grows best in moist soil and forested areas which allows the tree to produce numerous Garcinia Cambogia fruits. The fruit is rich in an acid referred to as HCA (Hydroxcycitric acid), this is what gives the fruit its characteristic “sour flavour”. The acid HCA was discovered in the 1960s, found to be a derivative of Citric acid, differing by only a small change in its structure. 
Garcinia Cambogia in its native continent of Asia is frequently used in cooking, particularly in curry. Across Asia it is known as Malabar Tamarind and is used much like the traditional Tamarind in curries to add a rich flavour. In addition, due to its “sour flavours” it is also use to cure fish and tenderize meat. Throughout Ayurvedic history, Garcinia Cambogia has been treasured and famed as one of the great natural cures for illness and disease. It was typically used to treat indigestion and problems of the digestive tract . William Jackson Hooker, an English Botanist was the first westernised man to discover and write about the sour fruit in 1835  . Hooker played a massive role in bringing the growth and preparation techniques of the Garcinia Cambogia back to Western world for medicine.
What does Garcinia Cambogia claim to do ?
The main claim of Garcinia Cambogia is its promotion of weight loss and maintenance of a healthy weight. It does so by acting as an enzyme inhibitor for the enzyme Citric Acid Lyase. It inhibits de novo lipogensis, “novo” meaning new, “lipo” meaning fat/lipid and “genesis” meaning formation or creation. Citric Acid Lyase targets the production of fat from excess carbohydrate, inhibiting at this phase impedes the laying down of new fat deposits, thus, reducing weight gain . There is much debate about the efficacy of this, yet many studies show that Garcinia Cambogia can be used in conjunction with a healthy diet to promote consistent weight loss. One study showed that there was a significant decrease in fat mass in the group that took daily doses of HCA . Additionally, 2 studies showed in agreement that groups taking a daily dose of HCA also had lower visceral and subcutaneous fat store compared to the control group. 
In addition, Garcinia Cambogia has also been linked with :
- reduced cholesterol
- joint pain
- bowel health
- improved immune function.
Where can I get it from ?
The raw fruit preparation includes a complicated mix of steps such as slicing, burning and drying. This is not recommended, and these fruits in their raw form are not widely available. However, supplement companies have begun manufacturing easy to swallow tablets to provide access to resources such as this in a more convenient way.
Look for tablets that have a dosage between 25-78mg/kg body weight/day. Or alternatively look for the HCA, active ingredient content. It’s advised to take between 900 and 2800mg/day to see effects, but over no more than this, as it can become toxic. 
Note they can also be consumed in tablet, capsule, chewable and liquid forms.
- Orwell, S. Frank,K.. (2012). Garcina Cambogia. Available: https://examine.com/supplements/garcinia-cambogia/.
- Potential treatments for insulin resistance in the horse: A comparative multi-species review". The Veterinary Journal (Science Direct) 186: 282–291.doi:10.1016/j.tvjl.2009.08.032. Retrieved 6 October 2013.
- York-Morris,S. (2015). 29 Things You Didn’t Know About Garcinia Cambogia. Available: http://www.healthline.com/health/food-nutrition/things-you-didnt-know-about-garcinia-cambogia.
- Cox,L. (2015). What is Garcina Cambogia?. Available: http://www.livescience.com/39243-garcinia-cambogia-supplement-facts.html.
- Basu.A. (2010). Meals that Heal-Soul Curry. Available: http://www.thehindu.com/features/metroplus/Food/meals-that-heal-soul-curry/article515598.ece.
- Reddy,C. (2012). All About Garcina Cambogia. Available: http://theindianvegan.blogspot.co.uk/2012/10/all-about-garcinia-cambogia-fruit.html.
- Allen, Mea 1967. The Hookers of Kew 1785–1911.Joseph, London.
- Drugs.com. (2014). Garcinia Cambogia (hydroxycitric acid). Available: https://www.drugs.com/npp/garcinia-hydroxycitric-acid.html.
- Roongpisuthipong.C, Kantawna.R and Roongpisuthipon.W.. (2007). Reduction of adipose tissue and body weight: effect of water soluble calcium hydroxycitrate in Garcinia atroviridis on the short term treatment of obese women in Thailand.. Asian Pacific Journal of Clincal Nutrition . 12 (1), Pg 25-29.
- Hayamizu,K. Et-al. (2003). Effects of garcinia cambogia (Hydroxycitric Acid) on visceral fat accumulation: a double-blind, randomized, placebo-controlled trial.. Current Therapeutic Research, Clinical and Experimental. 64 (8), Pg. 551-567.
- Hayamizu K, Ishii Y, Kaneko I. Effects of long-term administration of Garcinia cambogia extract on visceral fat accummulation in humans: a placebo-controlled double blind trial. Journal of Oleo Science.2001;50(10):Pg. 43–50.
- Therapeutic Research Faculty . (2009). GARCINIA. Available: http://www.webmd.com/vitamins-supplements/ingredientmono-818-garcinia.aspx?activeingredientid=818.